Teenage achievement and the house price bubble

The general economic context of where and when you grow up matters. Think, for example, of those raised during the Great Depression in the US or World War II in Europe who are likely to be very careful with their spending, never through anything away and finish their plates. In this regard, what should we expect from those reaching adulthood in the past years?



Daniel Cooper and María José Luengo-Prado study the impact on teenagers of the house price boom before the current crisis in the United States on educational outcomes. Using the Panel Study of Income Dynamics (PSID), they find that a 1% higher house price at age 17 leads to a 0.8% higher income as adult if the parents owned the home, 1.2% lower if they were tenants, after conditioning for socio-economic characteristics. These are big numbers. They can be justified by the observation that higher house prices allows more collateral to borrow for education. Indeed households with a below median non-housing wealth saw even a 1.6% boost in their child's future income. To explain the impact on tenants, I suppose one can explain it with higher tuition in reaction to larger loans, which tenants cannot afford as well.



The consequences from the recent house price crash are daunting in this context. And given that state are disengaging themselves from financing their public colleges, leading to even higher tuition, the outlook is even worse.

File sharing and the structure of the music market

For as long as music has existed, artists have lived from performing. The advent of packaged music (radio, TV, disk, tape or CD) has changed little to this, as the new medium has been more about promoting the artist than making money for the artist, with few exceptions. The ones making money from sales are the record companies, and the appearance on file-sharing is challenging their business model while not affecting the artist's way of living. In fact, the latter appreciate the zero marginal cost promotion. But the record companies want to survive.



Ralf Dewenter, Justus Haucap and Tobias Wenzel study the interaction of record and ticket sales under the assumption that both benefit from each other. Clearly, the impact of file sharing is ambiguous: it may increase record sales if people discover an artist through file-sharing and attend a show. But some potential sales are lost when a very close substitute is available for free. The solution for the record companies to to take over the management of concerts as well. Whether the artists want to go along with that is another question.

Do we need awards in Economics?

I do not like awards. They always create jealousies, and one cannot help that whenever a committee is involved, something may not have gone right. I am thus quite happy that economists give very few awards. It makes their CVs look bad compared to other scientists, but that is the price for a relative peace in the profession.



But we still have some prizes. The Nobel one, which is not really part of the Nobel family but is still attributed much prestige is always under much scrutiny. And in the end, the right people tend to win it. There have been a few controversial cases, Myrdal, Hayek, Buchanan and Ostrom come to mind as example where quite a few eyebrows were raised, but overall this award works well.



The American Economic Association gives an award that is considered to be even more difficult to get than the Nobel Prize: the Clark Medal, given to an American aged under 40. It is difficult to get because only one is awarded every year (no joint winners) and until recently it was given every second year. When comparing to the Nobel Prize, it is relevant to understand that American get a vast majority of them.



Now let us have a look at the past few year for the Clark award:

2011: Jonathan Levin, PhD MIT, Faculty at Stanford

2010: Esther Duflo, PhD MIT, Faculty at MIT

2009: Emmanuel Saez, PhD MIT, Faculty Harvard then Berkeley

2007: Susan Athey, PhD Stanford, Faculty at MIT then Stanford and Harvard

2005: Daron Acemoglu, PhD LSE, Faculty at MIT

2003: Steven Levitt, PhD MIT, Fellow at Harvard then faculty at Chicago

2001: Matthew Rabin, PhD MIT, Faculty at Berkeley

1999: Andrei Shleifer, PhD MIT, Faculty at Princeton, Chicago and Harvard



Do you see a pattern? Well I do, and others have, too. I am not saying these awardees are not bright and promising economists, but is there really no other qualifying economists that could have received it? Of course, John List comes to mind, who has no connection with MIT (or Harvard). But it actually worse than that. The award is given by a small committee, designated by the AEA. The AEA leadership is stacked with people with MIT and Harvard connections, so they also nominate their friends to the various committees, and you see the result.



It is even worse. In 2010, Ester Duflo was considered to be in the pool of strong candidates for the award. Guess who was on the awarding committee? Abhijit Banerjee, her PhD advisor, frequent co-author and colleague at MIT. In such a situation, an ethical person would decline the invitation to serve on the committee. That does not seem to have crossed the mind of Banerjee, who may be used to this cronyism.



There is another award, this time given by the European Economic Association: the Yrjö Jahnsson Award, to an European economist under age 45. It is given every two years, but can have several recipients. This awards has looked much cleaner because the committees and awardees have been distributed all over Europe. Europeans are indeed very sensitive to this. The last one was a shocker, though. Armin Falk won it to the surprise of many. And guess who chaired the awarding committee? His advisor, Ernst Fehr. Again, ethics would have indicated that if Falk had a chance of winning it, Fehr should have recused himself not just from chairing the committee, but from participating in it. In retrospect, this is not Fehr's first wrongdoing: two years earlier he was also on the committee when Fabrizio Zilibotti co-won the award. Zilibotti is a colleague of Fehr in Zurich.



I think we should do away with these two awards. It simply does not work.

Trust in private money

Money does not have to be supplied by government. Private money could work under some circumstances, and it has in particular been argued that competition should be beneficial. While previous attempts have failed, the wider availability of information, rating agencies (gasp) and information technology could make it happen. So it is of interest to find out what those circumstances are.



Ramon Marimon, Juan Pablo Nicolini and Pedro Teles say that money is an experience good, as you only observes its quality after the exchange is performed. This leads to serious limitations. If issuer of currency cannot commit to not inflate in the future, then competition over currency in the present has no bite. Building a reputation can solve this to some degree, but building the necessary trust means that future rewards must be larger that immediate gains from inflating. That implies that full efficiency cannot be attained: inflation needs to remain positive, while full efficiency implies negative inflation so that money has the same return as a risk-free bond. Unfortunately it also implies that there is indeterminacy and any inflation rate could happen. Oh well, may be the government could step in to help achieve efficiency...

Public consumption and the business cycle

One aspect of government purchases the current crisis has highlighted is how volatile they can be. Quite obviously, they are influenced by politics, to the point of complete reversal between massive spending and severe belt-tightening within months as in the US and the UK. But there could also be a more systematic component that is linked to the business cycle. After all, the government may be trying to improve the welfare of its constituents and for example substitute public consumption for lacking private consumption, or the same for investment.



Ruediger Bachmann and Jinhui Bai look at this using an augmented real business cycle model. They claim that 25-40% of the variance of public consumption can be accounted for by shocks to total factor productivity once implementation lags and costs of public consumption, as well as taste shocks to public vs. private consumption. I am no particular fan of taste shocks, as they are the symptoms of a modeler who is giving up on trying to explain something and simply equates the error term in the Euler equation to a shock. Then much is driven by how this shock is calibrated, in this case to match a four year electoral cycle and some data moments. When I think about shocks in this context, I think indeed about who is in power to decide on public expenditures. But that is not completely exogenous. Indeed, the state of the economy has an impact on who gets elected or reelected. And this can be calibrated without trying to match the data moments one is trying to explain.

Job referrals can be more efficient than open search

I a perfect world with heterogeneous workers and jobs, the matches are those that maximize efficiency. But when information about the quality of either is private and cannot be revealed credibly, the economy quickly looses efficiency. The solution is then to make hiring and firing easy, so that good matches can be found by trial and error. Employers also try to gather information about their potential employees, and their socio-demographic characteristics are certainly among them. While this looks like discrimination, it is OK if it is only statistical discrimination. But one can improve on this.



Christian Dustmann, Albrecht Glitz, and Uta Schönberg study job referrals from co-workers. They find that typically shunned minority workers are more likely to be hired the more other minority workers are already present, a clear sign of job referral. In addition, these workers earn on average higher wages and are more likely to stay in such firms. In some sense, this shows that job search networks can be better than open competition under some circumstances. One could even stretch the argument to claim that favoritism could be beneficial.

Penis size and growth

Understanding why some countries are poor and why some grow than others is probably one of the most important questions in Economics. The traditional tool to tackle this challenge has been growth regressions: use cross-country data and regress the GDP growth rate on various indicators that could be relevant in order to find which matter most. These regressions have been abused over the years, especially as there are obvious endogeneity and collinearity issues. Also, the results are driven by a multitude of (poor) countries where data quality is quite horrendous. The worst is probably all the data mining that is going on in this literature, which culminated with Xavier Sala-i-Martin's two million regressions.



Tatu Westling uses a variable the previous literature completely ignored: the average length of the erect human penis. Adding this variable to the regression shows a U-shaped relationship for the GDP level, explaining 15% of its variation. The optimal penile length is 13.5 cm, and 16cm is disastrous. For GDP growth, the relationship is negative, explaining 20% of the dispersion. This is not negligible, and more than institutional variables that are thought to be the key to growth and convergence.



I wonder how many people will take these results seriously and try to get policy recommendations from it. Westling hypothesize about the impact of self-confidence. The paper is very well written, taking the 'male organ hypothesis' very seriously, but in truth tongue-in-cheek. Very different from this study on flag colors I wrote about previously.

Sustainable retirement pension reform?

With increasing longevity, it is obvious that something needs to be done to keep pension systems around the world sustainable. The main options are postponing the normal retirement age, lowering retirement benefits or increasing contributions. The typical studies that compare these options and are thrown around in the public arena are done by accountants and actuaries, who do not take into account the changing incentives of market participants. Economists can do better.



Peter Haan and Victoria Prowse take up the challenge and estimate a very complex life-cycle model for Germany. It includes idiosyncratic risk, consumption and labor supply decisions and a complex tax structure. They find that the 6.4 year increase in life expectancy over the next 40 years needs to be met either by an increase in the full-pension age by 4.3 years or a reduction of benefits by 38%. The first approach markedly increases the unemployment rate. This is ironic in Europe where a reduction of that age is typically viewed as a way to reduce chronic unemployment among the young. The other option would markedly increase savings, as people have to fend for themselves more. Consumption of retirees is higher in the first option though.



Am I satisfied with this study? It is much better than what you typically see, yet I want more. The easy bit is that one could actually determine whose welfare increases under which option. That could help in understanding the (political) feasibility of such reforms. And maybe a combination of them turns out best. More critically, the model does not attempt to consider the consequences in the changes in aggregate supply. Lengthening the work age this much increases the work force dramatically and must have consequences for aggregate, and thus individual, wages. Also, while the matching probabilities and wages of retirement age workers are estimated from current data, I do not think these estimates apply once more previous retirees are forced into this pool. The new ones have different qualities compared to those who would have continued working anyway. Therefore, I see more work to be done.

Procrastination in team work

Teamwork can turn out very bad when moral hazard is present: if people do not trust each other or care about each other, nothing gets done. When doing research, we are lucky to be able to choose our co-authors, but even then things can turn for the worse if a team member looses interest. And we remember how bad it is when a team is forced upon you during our studies. Now, this is all very loose reasoning, let us get on firmer ground.



Philipp Weinscheink studies team production in a dynamic game with moral hazard. If all players are rewarded equally, they will all wait until the last moment to participate. This is very like what we often see in political negotiations with a deadline, where nothing happens until the last moment, and player consciously wait for the last moment. The same often happens at collective agreement bargaining. And of course, the outcomes are far from optimal, as the debt ceiling mess in the US has recently shown.



If the rewards are not equally distributed, the outlook is better. Quite obviously, those who are rewarded better will tend to procrastinate less. But they are not necessarily better off that those less rewarded, as they put more effort. Thus, second-best contracts are unequal ones. But all this falls apart if some players have limited liability (which means they have better outside options) or if some can sabotage. Then everyone will wait until the last moment and very little gets done. Think about the US situation again...

Has the US economic policy been Keynesian for centuries?

Suppose the abstract of a paper starts with "It is demonstrated that the US economy has on the long-term in reality been governed by the Keynesian approach to economics independent of the current official economical policy." My first reaction is that of puzzlement, as I would not have thought as the US being particularly keen on Keynesian policy, except for the recent years (which are not considered in the quoted study). But again, data may speak differently from policy intentions, so let us dig deeper.



A. (Agung?) Johansen and Ingve Simonsen come to this stunning conclusion by looking at the correlation between (nominal?) (federal?) public debt and the Dow Jones Industrial Average. One can first question whether public debt is a good indicator of Keynesian policy. Public deficits or even public expenses would be better. And does the DJIA represent the US economy? It is certainly not an indicator of current activity, but rather of expected present value of future profits from a particular class of firms.



Whatever. Let us go with that. The analysis is done by computing over the 1791-2000 sample a sliding correlation between these two indicators over a five-year window. Surprise, the correlation is zero most of the time, except during some wars when it is strongly positive (and strongly negative during the second war with the Seminole Indians). From this they conclude the Keynesian policy was mostly pursued during wars. Now let us take a step back: the authors show that there is by their definition no Keynesian policy during peacetime. But during wartime, the government is credited with a policy geared towards expansion of the DJIA. They, one may ask, if this is the government overwhelming policy, as the authors seem to believe, why did the US wait so long to get into the two World Wars when the opportunity was there? I cannot make sense of all this.

Land titling and access to credit

It is widely believe that a key ingredient of economic development is the accessibility of credit. Indeed, entrepreneurs typically need credit to develop their business plans, and much of capital accumulation is performed through credit. But no one is going to grant credit on a promise, some collateral is needed. And that is a problem in many developing economies, as people hold little property and even land is communal or without clear property rights. Hence the idea that distribution of untitled land, with well-established property rights, should provide collateral to a large fraction of the population and make credit possible. How does this work in practice?



Caio Piza and Maurico Moura study the case of a major land titling initiative in Brazil. They use an interesting natural experiment. Two neighboring and very similar communities of the city of Corosco (correction: Osasco) were to get property titles for every inhabitant, but five year apart (2007 and 2012). This leads to a nice control group, which allows to overcome the problem of the endogeneity of ownership rights of a typical study by using a difference-in-difference approach. Indeed, the authors conducted a survey in 2007 before the titling, and another one in 2008. In addition, the context here is urban, which is unusual for a titling study. It appears access to credit increases by 22 percentage points, or about a half, within 18 months of titling. This is major. I do not think such large estimates have been found in rural studies. And given that developing countries become increasingly urbanized, this is very interesting.

Convergence in recessions

Growth theory and data teach us that, at least in developed countries, economies tend to converge in the long run: the dispersion across regions or nations of per capita income (or similar indicators) tends to decline. While this is a long term phenomenon, there is a priori no reason to believe this is a constant process.



Eldon Ball, Carlos San Juan and Camilo Ulloa study total factor productivity in agriculture across US states. While they indeed find a general trend towards convergence, it turns out that its speed is much faster during recessions. Why would this happen? If we follow Schumpeter, the worst firms should be dropping out during a recession, thereby relatively increasing TFP in the worst areas. And voilà, you have faster convergence. But only farm-level data would tell whether my conjecture is true.

What if the US looses its reserve currency privilege?

Since the Bretton Woods agreement in 1945, the United States have enjoyed the so-called "Exhorbitant Privilege." During the fixed exchange rate regime, the US could conduct monetary policy without regard to what was happening in other countries. The US dollar was a reserve currency, which also helped the US maintain low interest rates and a guarantee that US dollars (and Treasury bonds) would always find a buyer. With flexible exchange rates, not much has changed. But with the recent shenanigans in a Congress that considered reneging on its debt, the likelihood of this advantage changing has dramatically increased. What would the consequences of the loss of the Exhorbitant Privilege be?



Wenli Cheng and Dingsheng Zhang study this scenario using a general equilibrium model where a peripheral country (say, the Asian economies) pegs its currency to the money of a central country (say, the United States), the latter being used as the vehicle currency for international trade. In addition, the foreign exchange reserves of the periphery are invested in government bonds of the center. This means that no matter what current account deficit of the center, it is always financed by the periphery. Yet the center may be tempted to inflate it away. This limitless and to some extend free borrowing is the Exhorbitant Privilege.



Now remove it by assuming that the periphery does not want to invest in the center, either because it views the Treasury bonds are excessively risky or because it does not peg to the dollar any more. This would lead to a dramatic readjustment of the terms of trade to favor the tradable sector of the center. This decpraciation of the dollar would be more pronounced of the center is incapable of raising taxes and finances its debt with inflation. This already all sounds familiar.

About very large risk aversion estimates

The equity premium puzzle is an enduring challenge to our estimates of risk aversion. Indeed, as Rajnish Mehra and Edward Prescott have highlighted, the only way to reconcile a standard model with the observed long-term equity premium is to assume a risk aversion coefficient of 10, while micro-estimate hover around two. This puzzle has been resolved a little bit in various way, most prominently by taking into habit persistence and some other deviations of the standard CRRA or CARA utility functions. But all this still boils down to a risk aversion parameter that is linked by an identity to the intertemporal elasticity of substitution (it is the inverse). But we know how to disentangle the two.

Xiaohong Chen, Jack Favilukis and Sydney Ludvigson estimate a model with the recursive preferences of Larry Epstein and Stanley Zin and Philippe Weil. This is not obvious to do because to estimate the coefficient of risk aversion in this context, one needs a measure of claims to future consumption. Here this is overcome by estimating nonparametrically the continuation value of the consumption process from within the model. The result is that the elasticity of intertemporal substitution is above one, and the coefficient of risk aversion is somewhere between 17 and 60. These are huge numbers. But they still imply a rather modest and sometimes even negative risk premium.

Aid and remittances as hedges against food price shocks

Food is a substantial part of household expenses in developing economies, and in many of the latter foreign aid and remittances from emigrants provide a substantial part of national income. As world food prices have been subject to large fluctuations lately, causing much grief and even riots, it is natural to ask whether aid and remittances can provide some smoothing against the effects of these fluctuations.

Jean-Louis Combes, Christian Ebeke, Mireille Ntsama Etoundi and Thierry Yogo use a cross-country panel data set to study this question. First, they confirm that food fluctuations have a notable impact on aggregate consumption, especially in the poorest economies. Second they find that aid and remittances do help, and remittances seem to be more efficient at hedging. Indeed, an aid-to-GDP ratio of 29% is theoretically necessary to absorb food price fluctuations, while 9% is sufficient is for remittances. Only Mozambique and Nicaragua satisfy the first, while a few more countries satisfy the second.

How is China now planning its economy?

Since 1978, China has undergone a fundamental and very successful reform from a planned economy towards a market economy. But one should still keep in mind that this is still an autocratically governed country where technocrats call the shots at all levels. China is still working with five-year plans and the economy is still tied to administrative goals. SO how does economic planning work in China nowadays?

Gregory Chow offers some insights, in particular on how this planning has recently become more important due to the global economic crisis. Administratively, policy is guided by the five-year plans, which interestingly have recently included new sections on welfare and management of society, making apparent some worries about the adverse effects of market economies and rapid development (or democracy when people can complain?). The remarkable part of these plans is that explicit targets are set, and policy is in a major way oriented towards these targets. Of course, the government still controls directly a considerable number of state-owned enterprises. And it has the traditional tools of policy in a market economy at its disposal to influence the rest of the economy. These policies are coordinated at all levels thanks to the very central nature of government.

In some sense it would also be good for market economies to also set some targets for policy. In fact, this is what politicians should be arguing about and then let technocrats put policy in place to achieve these targets. I would not mind targets like putting a man on Mars by 2020, making sure everyone in covered by health insurance by 2015, get 50% of commuting kilometers on public transportation, or defense expenses being completely dedicated to defense (and not attack) by 2015, for example. In fact, the World Bank has well-defined targets for developing economies. In do not see why this should not be applicable for developed ones. At least it would make governments capable of rallying support for some goals and be explicitly accountable.

Policy risk and the business cycle

The US economy seems stuck in its tracks, and many blame uncertainty about future public policy, including me. Indeed, private firms are currently sitting on a lot of cash and are making very good profits, yet they are not investing or hiring. This really looks like a wait-and-see game. But it this justification well-founded or is it just a cheap excuse to justify higher than usual profits in the face of high unemployment?

Benjamin Born and Johannes Pfeifer put some structure into these arguments by taking a standard New Keynesian model and adding uncertainty about monetary and fiscal policy. They measure this by looking at tax rates and monetary policy shocks with time-varying volatility. Previous literature already looked at the impact of aggregate uncertainty, which policy makers can do little about. But policy uncertainty is another matter. And there is hope, as Born and Pfeifer show that the impact of policy uncertainty is not that important (but much larger than uncertainty about productivity shocks) thanks to monetary policy reaction through a Taylor Rule. So that is somewhat reassuring, but then the size of the current policy uncertainty is an order of magnitude larger than when this paper was written, and monetary policy is bound by non-negative nominal interest rates.

The debt ceiling circus is another media debacle

If you compare the media coverage about the current debt ceiling "discussions" in the US to abroad, it is a stark contrast of style. While the US media is focused on the power haggling of politicians, ignoring completely policy matters, foreign media puzzle why such a silly policy the Republicans are proposing is even being discussed. And once more, it makes me wonder why the US media is sleeping.

Roughly, the Republicans want to erase the public deficit from one day to the next, in the middle of difficult times, and without raising taxes, cutting anything to defense expenses and farm subsidies or closing corporate tax loopholes. This is mathematically simply impossible and must results in partial default on public debt, a major increase in interest rates and in then more public expenses to service the debt. In other words, this is an own goal. To top it, the policy uncertainty is severely hurting the US economy which does not seem to be able to get back on track.

The saddest aspect of this is that the media is completely oblivious to this. It is so obsessed to present both views that it shows without critical discussions complete absurdities from the Republicans. I have a hard time understanding the motivations of the right, except hurting the economy ahead of elections or participating in some grand scale insider trading, and nobody in the media is pointing this out. In fact it is relaying the arguments that decreasing taxes will increase revenue, especially if the rich get those breaks. To repeat myself, this is so wrong, especially now. If you want to improve the economy and insist on reducing the deficit, give tax breaks or transfers to the poor and tax the rich significantly more.

The worst is that there are some serious negative externalities on many who have absolutely no say here, and not just the US tax payers, but also foreign economies. Rarely have I seen such a policy kamikaze, say since Saddam Hussein invaded Kuwait. But at least the US media was then on top things.

Referee home bias

Referees are supposed to be impartial. In academics, this is most of the time helped by the fact that they are anonymous. In sports, referees are public and meeting participants, including spectators, try to influence them. This becomes particularly relevant when the referee has to take a decision against the home team than leaves spectators irate. They could retaliate against him. Does this influence referees?


Andrés Picazo-Tadeo, Francisco Gónzalez-Gómez and Jorge Guardiola Wanden-Berghe look at first division football in Spain, carefully taking into account stadium capacity, how full it is, how far spectators are from the pitch, and referee experience. They find that awarding a free kick does not have a home bias, which is consistent with the fact that this is a split-second decision. The ensuing decision to give the offending player a caution is, however, affected by home bias. This decision is not instantaneous, and social pressure can be exerted on the referee, especially when the stadium is full. The presence of a running track that separates the local supporters form the action does not seem to matter, though. I wonder whether some teams have a larger home bias than others, as the fans' reputation could also influence referees.

Do unemployed and employed compete for the same jobs?

In times like now, it is easy to forget that job seekers are not only the unemployed, but also the currently employed. On-the-job search is rather common but difficult to measure, as it is often not openly conducted. But it is important to understand it for policy, for example to evaluate the impact of job creation programs.

Simonetta Longhi and Mark Taylor just finished a couple of papers that offer some insights about these two types of job seekers in the United Kingdom. In the first one, they compare their characteristics and search behavior and conclude that employed and unemployed job seekers are different. My reading is that the unemployed are often stuck in a sequence of low paying jobs and drift in and out of employment. The employed job seekers are rather on the way up and improve their situation at each change. Thus these two types are not substitutes and do not compete for the same jobs.


In the second paper, they compared the job finding probability of both types. Consistently for search theory, they observe that on-the-job seekers take much longer to find jobs, reflecting that they can afford to wait for the perfect match. The unemployed, however, have content themselves with the first offer, especially since unemployment insurance criteria have tightened in the UK. The presence of the former has no impact on the search success of the latter, confirming that they are not substitutes.

Kuznets in a post-industrial world

The Kuznets curve traces the evolution of inequality as an economy develops. It is based on Kuznets observation that income and wealth inequality increased and then subsided as economies get richer. While this was established on a cross-section of countries, it has been proven right in the time dimension in some cases, like England and Wales through the Industrial Revolution. But what happens thereafter, when an economy further develops into one where the service sector dominates or globalization becomes most relevant?

Jordi Guilera asks this question noting that most developed economies have recently experienced a sharp increase in inequality. Is thus Kuznets' inverted-U becoming a N? Beyond simply observing this, one would also need a theory with predictions about other correlations to make some progress. The theory here is that skill-biased technological change generates increasingly large education premia, and evidence from long-term wage inequality in Portugal seems to corroborate this hypothesis. In particular it shows that inequality between sectors was the leading determinant of inequality until the 1980s, while inequality within sectors has taken over now.

Trade constraints of developing countries

With all the current posturing in the US and Europe, while addressing doubtlessly important problems, it is easy to forget that there are much bigger issues that need to be solved: how to get the poor and especially the poorest economies to a decent standard of living. We have been blessed to be born in the right families and in the right countries, and we should share this luck with those who were no so fortunate. This does not necessarily mean to give to the poor, just giving them a fair chance may be enough.

Jean-Jacques Hallaert, Ricardo Cavazos Cepeda and Gimin Kang consider the consequences of trade barriers on developing economies. The latter should be able to benefit greatly from selling on world markets goods produced with the factor they are relatively rich of, unskilled labor and to some extend land, while importing the complementary goods, likely capital-intensive investment goods. This OECD study finds that developed economies cannot do much more in terms of reducing import tariffs. Where there is more potential is with home-grown issues: unreliability of electricity, high transportation costs, poor education, bad governance, and instability. These results have been obtained by regressing exports, imports or their sum on a number of indicator for a panel of data. I am not particularly keen on these exercises due to poor data quality, gigantic endogeneity and especially the fact that proxies for essentially unquantifiable variables are used, like property rights and governance. But I suppose this is the best one can do, and the results appear to be rather stark. Now as to how to solve these economic problems, that is a gigantic task that we should be really talking about these days, instead of posturing for political gain.

How not to think about class struggles

Depending on the research question being asked, some degree of heterogeneity is required in a model. Sometimes this modeling requires distinguishing between those who provide capital and those who work. This is obviously an abstraction, because in reality these "capitalists" may just be shareholders who also work on the labor market. In fact, they often are, and they save and invest for various purposes, like self-insurance, retirement or bequests. But making households purely capitalists and workers can sometimes prove useful in making a result emerge more clearly, as long as one is conscious of the abstraction. In some circumstances, it is useful to explain why these "classes" emerge, like differences in access to credit or in subjective discount rates. But again, these are abstractions useful for modeling.

Alberto Russo takes this abstraction very seriously. In his model, people are born capitalists or workers, which translates in households either investing in an activity with a multiplicative risk or working for a wage with additive risk. Why that is so and what should be achieved with this is left unexplained. Households face an additional risk: they randomly switch between classes, the probability depending on wealth. The model is "closed" with exogenous and distinct propensities to consume for both classes. The model is then calibrated with parameters values not related to anything observable. The simulations reveal that if one starts with everyone having the same wealth, wealth heterogeneity then emerges. Well, that was unexpected... Even back in 1993, Mark Huggett had a much better model to explain heterogeneity in wealth.

We are turning into a rentier society again

Wouldn't it be nice to live on old money? One does not really need to work, or at least on a regular basis, one is worry free, and one gets to enjoy life at its fullest. But this is only a dream that is reserved to a preciously small elite.

Thomas Piketty, Gilles Postel-Vinay and Jean-Laurent Rosenthal show that about a century ago in Paris close to 10% of the population were in fact rentiers, that is, people who consume more than their labor income during their lifetime. They thrived in an economy where the return of wealth was substantially higher than the growth rate. And by the looks of it, it appears that we are heading into a similar situation, as a small proportion of the population is generating substantial wealth from labor income, wealth that cannot be spent in a lifetime and will be inherited by happy an idle descendants. Perhaps more importantly, existing wealth is enjoying far better returns than average wages are growing at, laying the seeds of a new rentier society. History repeats itself.

Obesity on the German labor market

Being obese makes you a social outcast, especially in countries were obese people are relatively rare. This can have consequences on the labor market, as there is plenty of evidence that handsomeness matters, for example. So are obese people discriminated against on the labor market?

Marco Caliendo and Wang-Sheng Lee look at newly employed people in Germany and find that there is not much evidence of discrimination there. Only obese (but not overweight) women may be suffering in the land of beer and wurst. Of course, one may question the validity of a study that must be relying on very few observations for a subgroup of the sample. Yet, surprisingly, half of the men and 37% of the women are considered overweight or obese, proportions I would never have imagined from walking around German towns. And with sample ages averaging in the thirties, they are relatively young too. As the survey sample is based on people who have been unemployed, I wonder whether the discrimination is rather in unemployment rather than employment.

Is it cheaper to live in poor economies?

If you are a rich country resident and travel to a poor country, you are continuously amazed how inexpensive life is there. One rationalizes this with the lower local wages which make domestic goods (and price discriminating imports) cheaper. Is this anecdotal evidence true in general? Does it hold across all countries?

Fadi Hassan finds that indeed rich countries have higher price levels. But once you go further down the development ladder, the statistical evidence is not that clear, and once you reach the lowest rungs, the cost of things could be increasing again. This analysis is performed using the ratio of purchasing power parity to the exchange rate, as measured in the Penn World Tables and finds that the best non-linear fit of the price-income relationship is not increasing for 40% of the countries. The challenge is now to understand why it is so.

Public pensions are not sustainable, even in Norway

By now, everyone must be aware that populations are getting older and that this puts some serious strain on pension systems. Unless one plans far ahead or is blessed with substantial sustained growth, some problems in financing retirement will appear. But there must be some place that is going to do fine, say a country with a forward-thinking government, a recently reformed pension system, a well managed endowment of natural resources and a small and smart population, like Norway. Right?

Wrong, say Christian Hagist, Bernd Raffelhüschen, Alf Ering Risa and Erling Vårdal. To come to this conclusion, they use generational accounting, which measures the fiscal sustainability of the public sector and in particular the publicly funded retirement pensions. The latter went this year through a significant reform, which includes pension indexation below wage growth, benefits adjusted to be actuarially fair if life expectancy increases further, and work incentives for elderly. It turns out the pension reform has helped substantially for the sustainability, about as much as the presence of the endowment of oil and natural gas. But that is not going to be enough, even with higher oil prices and an exceptionally well managed petroleum wealth. And for those hoping that future growth of the economy or higher fertility would help, well at least in the case of Norway this would barely help. To close the gap, a 17% increase in taxes would be needed, and they are already very high in this country. So, if Norway cannot make it, how could countries with inactive governments and little or poorly managed endowments make it?

Should we encourage business ownership?

Politicians claim left and right that small business owners are critical to the success of an economy. They woo them with various tax credits and by turning a blind eye to their opportunities to hide income from taxation. Yet, politicians also rewards large companies with generous tax abatements, especially when the relocate or just promise not to move away. So, in the end, who should be encouraged. the small business owner or the big conglomerate? In part, this is a question about whether it is better to have many self-employed workers or many employed workers.

Mirjam van Praag and André van Stel address this question by trying to determine the optimal business ownership from a sample of 19 OECD countries over 26 years. They proceed by estimating a Cobb-Douglas production function augmented with a business ownership rate, its square, tertiary education, as well as interactions of the latter with the formers. This is not a production function that has an interpretation for factor shares, it is rather a test of some relationships in the data. And by the implied non-linearity, it allows to computed from the regression coefficients what the optimal business ownership rate would be. On average, it is 12.5%, which is definitely not high, and it declines over time.

Furthermore, van Praag and van Stel find that countries with a higher proportion of workers with tertiary education enjoy a lower optimal business ownership rate, converging towards 11% when everyone has a university education (no gravediggers?). The interpretation they offer is that better educated people run larger firms. As business owners are a minority in a developed economy anyway and only the top business owners really matter for economic performance, I am not quite convinced by this argument, but it is apparently supported by microeconomic evidence. I would have rather thought that a more educated workforce is more specialized, and under such circumstances it is more difficult to be a business owner. The only exception are start-ups, which then either fails or are gobbled up by a larger firm.

Razor innovation in macroeconomics

Macroeconomics is sometimes like Gillette razors. There is regularly an innovative razor that happens to have more blades than the previous one. And once it gets out of hand, the new razor goes back to fundamentals and has only one blade, before the cycle starts again. In macroeconomics, there was this fad of adding more an more shocks to models until everything became very confusing and unidentifiable. So we returned to simple models (Occam's razor was the innovation) that became more powerful because of the presence of a market friction. Now, these search frictions are appearing everywhere, one-by-one or in pairs, and the latest generation of models has three frictions.

In a pair of papers, Etienne Wasmer alone and then with Nicolas Petrosky-Nadeau introduces search frictions on labor, credit and goods markets. The first is more of an exercise of style, showing it can be elegantly solved in steady-state thanks to block-recursiveness. The second paper is more interesting, as it looks at the dynamic properties of the model and shows that is can better account for the persistence of fluctuations in the data (what frictions are good at) and the volatility of labor flows. Interesting results, especially in the light of the pronounced lag in the recovery of employment in the US these days.

I am waiting for the four-friction model now.

Should immigration quotas be traded?

We all want to end world poverty, and a particularly efficient way to do this is to allow the free movement of people. Unfortunately, this often puts a burden on the receiving country, and thus immigration limits are set. But there is clearly a positive externality on the other countries from allowing immigrants in, as long as the others also care about world poverty. This implies that immigration quotas should be set higher.

To make this happen, Jesús Fernández-Huertas Moraga and Hillel Rapoport suggest a system of tradable immigration quotas, that mimics the market for pollution quotas. There is one difference, though, as migrants have preferences on where to go. Thus, there is a global number of migration slots put on the market and countries can trade them, paying for a slot elsewhere if local costs of immigration are particularly high. A central assignment authority attributes migrants to countries following their preferences and a particular assignment scheme.

This market allows to extract the price of immigrants to the host country as well as price the benefit of migration to world social welfare. Unfortunately, it does not appear immune to strategic behavior, as most bilateral assignment problems. But it seems to be a very promising step towards a better world, especially in the light of potentially large migration following climate change.

The welfare gain from inflation targeting

It is rather well accepted that transparency is preferred for policy, because it anchors better expectations, people generally do not like uncertainty, and discretion can lead to adverse biases compared to set policy rules. Yet, the United States exhibit little transparancy, with the Federal Reserve being one of the few western central banks not to declare some explicit policy target, and fiscal policy being as uncertain as ever. That would not be a big deal if the welfare costs were low, but you can think that there are high and in the case of fiscal policy are currenctly holding back the recovery.

Giorgio Di Giorgio and Guido Traficante are taking a closer look at the welfare benefits of inflation targeting. For this they use a model where households observe policy interest rates and do not know whether their changes are due to reactions to output gaps or shocks to the inflation target. Households are sophisticated, they use a signal extraction device to estimate the latent, unobservable variable. Yet, they still face substantial costs from the uncertainty. Money is not neutral because of Rotemberg pricing, a variant of Calvo pricing. Oh well, I guess this is what you need to do to get a result with some bite.

Households know there is a policy rule that determines the interest rate from the output gap (unobservable) and the inflation target (stochastic and persistent) as well as known preference and cost-push shocks. In other words, households know a lot about the structure of the economy and the shocks, except for the policy shock, but then somehow cannot figure out what the output gap is. The central bank can, though, but then has for obscure reasons a trembling hand when it comes to set its inflation target. That seems to be quite the opposite of what I would have thought: everyone is confused about the output gap, and only the central bank knows what the inflation target is. Instead of a story of households trying to disentangle output gap and inflation target from the interest rate signal, one would have a story of a central banker not quite sure what to do given the circumstances. Too bad, this could have been an interesting paper.

The military draft, mortality and education

The data sometimes work in mysterious ways and provide puzzling correlations that lead to interesting research questions. One such correlation is that exemption from military service leads to lower mortality later in life.

Piero Cipollone and Alfonso Rosolia find this while looking at a natural experiment following the 1981 earthquake in Southern Italy. Boys from the affected region were exempted from military service, and they were followed, along with non-exempted neighbors, to track their life and education. By concentrating on boys both sides close to the border of the exempt region, they find that those exempt ended up being more educated. I can easily believe that, as they were not spending some of their prime learning years hiding in bushes and peeling potatoes, and they were expecting a longer work life. But the exempt also have lower mortality. This is not due to a lower incidence of military accidents, it is rather linked to the higher school completion rates. In fact, the authors conclude that raising high school completion by 10 percentage points would lower mortality by one or two percentage points in the decade thereafter. That is impressive at that age.

The Internet did not raise a generation of loners

The image of the basement-dwelling World-of-Warcraft-playing loner is often shown as an example of the adverse impact of the Internet on social capital and in particular social interactions. Whether this is true is not so obvious, as the Internet also makes possible social interactions that could not exist before, as this blog shows in a limited way.

Stefan Bauernschuster, Oliver Falck and Ludger Woessmann study the impact of broadband Internet on social capital using a natural experiment in Eastern Germany. There, some choice by the telecommunications provider resulted in 11% of East German households to be on OPAL lines instead of DSL, which better supports high speeds. Using the German Socio-Economic Panel, they measure social capital with the frequency of going out, visiting friends and performing volunteer work. They find that Internet access has no visible impact on social capital. To the contrary, for children it seems to enhance social capital, possibly because it makes them aware of new opportunities to interact in real life. This is in stark contrast with television use, which has many times been shown to be detrimental to social capital, likely because it is a one-way communication, while the Internet can build two-way communication.

How should I lie?

Is it OK to lie? The usual answer is that it depends. Big lies are frowned upon, while small lies are somewhat tolerated. Does this necessarily mean I should avoid lying?

Gerald Eisenkopf, Ruslan Gurtoviy and Verena Utikal study the size of lies in an experimental setup. Their first observation is that it depends whom you are lying to. Honest people punish according to lie size, while chronic liars really do not care. Their second is that big lies are punished more than small lies. This is hardly surprising. What would have been more interesting to learn would be whether the punishment function is concave or convex, that is, whether the returns to scale are increasing or decreasing. In some sense we already have some idea about this by looking at tax penalties, which are usually proportional to the offense, plus a fix cost. And ultimately, one would want to compare the shape of the penalty function to that of the benefit function. Then I would finally know whether I should lie big or small.

State-owned banks in the US?

Many countries have state operated banks that support local development or other objectives that deviate somewhat from those of usual for-profit banks. No such institution exists in the US except for the Bank of North Dakota.

Yolanda Kodrzycki and Tal Elmatad study the Bank of North Dakota in the perspective of the feasibility of a similar bank in Massachusetts. They find that the BND is not a typical bank. While it favors local development, it rarely does so directly, but rather by helping local banks. It thus encourages a network of small and local banks, something that does not quite seem efficient to me. The BND was, however, not particularly useful in periods of crisis, like the agricultural crisis of the 1980s, because it also had financing difficulties. All in all, the bank of North Dakota is very different from state banks abroad, which offer all customer services like private banks and thus help regulate through competition some the excesses of private banking. The BND looks much more like existing development corporation that exist in most if not all US states. If Massachusetts just wants to em ulate North Dakota, it does not seem worth the large cost of the initial bond issue, especially in the current economics context.

Animals as forecasters

Futures markets and in particular prediction markets are a good way to hedge against various risks as well as establish what people really think about the likelihood of some event. As they a putting money on the line, these markets are deemed (and have proven) to be more really than surveys and polls. Of particular interest in this context was the short-lived "terrorism futures market" organized by the Pentagon, which was supposed to offer an additional tool for predicting terrorist threats, and which would allow those who could suffer from terrorism to buy insurance against it. Unfortunately, there was also a fear that threats could materialize because of the market, as people would try to manipulate it.

Adi Schnytzer and Yisrael Schnytzer point out that there is another potential for prediction markets: natural disasters. Of course, we humans are so far not particularly good at forecasting such events as earthquakes, but some animals have evolved a sixth sense in this respect that is rather underexploited. While it seems difficult for scientists to drum up money to study this, maybe because this technology does not seem credible or usable, the Schnytzers point out that if prediction markets are created for natural disasters, then funding would emerge if money is to be made. And this would also establish whether these theories have credibility.

Fiscal policy as insurance

The goal of fiscal policy is at the macroeconomic level to steer the economy towards efficiency and, depending on the country, to smooth somewhat economic fluctuations. It has long been debated whether this is desirable or possible at all, given the large delays in implementing public expenses. But changes to tax policies are quicker to put in place and implement. At the microeconomic level, the focus is more on the long term, again try to attain better efficiency as well to optimize some definition of fairness across economic agents, however this may be defined in the respective countries. These micro and macro aspects have largely been regarded as separate. This does need to be so.

Eduardo Engel, Christopher Neilson and Rodrigo Valdés look at the particular fiscal policy of Chile. This country is characterized, like many emerging economies, by wild fluctuations in economic activity. In this case this is triggered by changes in commodity prices, in particular for copper. The most important implication is that government revenue varies wildly (a macroeconomic impact) between 1 and 8% of GDP, which changes Chile's ability to redistributes across heterogeneous households (a microeconomic impact). Adhering to a balanced budget rule would have a dramatic effect, in terms of aggregate welfare it would be like renouncing to half of the copper revenue. The reason is that households' incomes is also correlated with copper revenue, and a countercyclical policy is then optimal. And to be the most effective, the poorest households are helped in hard times, both because they have the highest marginal utility from consumption and because they have the highest propensity to consume.

Chile has been pursuing so far something that is close to a balanced budget rule: expenses are related to a permanent income measure of income. This means expenses are relatively constant, except for the last years, where expenses grew significantly despite a reduction in copper prices. This appears to have worked well, in particular because the poor have been the target of this largesse, not the rich. That was stimulus spending done right. This paper shows how this can be done even better.

Do Italians trust the television or the judges?

In several countries, mass media have become, at least from my viewpoint, a dominant means of forming public opinion on just about anything. In the US it is particularly apparent that experts are less trusted by the public than media, or even less than people's prejudice. In politics, this is even more widespread, where media make or brake a politician, and politicians cater directly to the media. Imagine how things could turn when the politician owns the media. This is the current situation in Italy, where Prime Minister Silvio Berlusconi heads a formidable media empire and tries to fend off numerous accusations of corruptions and abuse of power (loosely speaking) that emanate from the judiciary.

Fabio Sabatini studies how much the Italian Prime Minister is trusted by the public. He finds that trust in television is by far the cleared determinant for trust in Berlusconi, and the second is lack in education, the third distrust in the judiciary. So much for Berlusconi claiming his empire has nothing to do with his repeated elections.

The child quality/quantity trade-off in the Industrial Revolution

Non-economists cringe when they hear us talking about investment in children and the quantity/quality trade-off in this regard. Yet, this is a very real aspect of child rearing pointed out by Gary Becker that is at the core of many models, and has been found wild in nature. This trade-off is though to be an integral part of the demographic transition, where fertility suddenly drops massively in the course of development.

Marc Klemp and Jacob Weisdorf look at data from Anglican parish registers from the 18th century that contain all sort of demographic data to look at the child quality/quantity trade-off during the Industrial Revolution. Theory tells us that if the returns to education and/or the cost of time (wages) get larger, parents switch from having many children with no education to few of them with better education. Klemp and Weisdorf's data indicates clearly that this trade-off is present: each additional sibling reduces by 8% the probability of a child eventually becoming literate. That is a strong effect, in particular considering the larger number of children at the time, and its rather large standard deviation during this time of transition.

Do not waste degrees of freedom with macro data

Dealing with microdata is relatively easy, as you have plenty of data points and can freely add explanatory variables with running the risk of running out of degrees of freedom. The story is different for macrodata, as series are much shorter, and one can quickly eat degrees of freedom by using lagged variables. The prime example here are the often abused vector autoregressions (VAR), that get larger and larger, and faster than new data points accumulate. The latest fad is to run regressions with time varying parameters, including in VARs, which is deadly for degrees of freedom as this is roughly equivalent to adding a boatload of dummy variables to the mix. Hence the need to be more parsimonious.

How parsimonious should one be? Joshua Chan, Gary Koop, Roberto Leon-Gonzalez and Rodney Strachan think the solution is in time-varying parsimony. The idea is that sometimes one needs a more complex model, and sometimes a few variables are sufficient. While this allows to spare degrees of freedom when one can do with few variables, this gain on paper is lost, and probably more than lost, by the implicit degrees of freedom used in selecting the right model. This is an old problem than is swept under the rug is many empirical applications, but in this case it becomes even more apparent because so many parameters and models are involved.

Venezuela's downfall

Venezuela was once the poster child in Latin America on how to do well (the opposite being Argentina), growing richer than European economies in the 1950's from quite modest means in less than two generations. And then all went downhill, and the country continues to slide into poverty. While many like to put blame on Chavez and his "revolution," the trend started long before he came to power.

Omar Bello, Juan Blyde and Diego Restuccia, instead of going through the usual case study that just rehashes anecdotal evidence, perform a growth accounting exercise to give the start of an answer. They find that the exceptional growth episode was due to a combination of plain old capital accumulation along with total factor productivity growth originating in the booming oil industry and its foreign direct investment transferring know-how to locals. The following collapse shows the undoing of this but with a very different origin. A severe misallocation of resources lead to a drop in total factor productivity, which then triggered capital loss. And how did the government manage ti create the mess? First, it steered the economy away from oil, which may be a good idea for diversification. But the second error was to favor heavy industries, a common development mistake. And third, general government meddling in affairs it should not be looking at. Chavez has just continued a long tradition in this regard.

Energy spending and household poverty

There is broad agreement that energy, especially polluting energy, is too cheap, calling for higher energy taxes. The problem is that such taxes are believed to be highly regressive, as poor households spend a larger share of their income on energy for transportation, heating and cooling. Of course, this could be alleviated by an appropriate redistribution of the proceeds, but to do this properly one first needs to understand well the energy spending of poor households.

Tooraj Jamasb and Helena Meier do this for the United Kingdom. There, households that spend more than 10% of their income on energy are considered "fuel poor" and deemed as having difficulties heating their home. I have always been suspicious of such definitions, as one may choose to spend more to heat at higher temperatures, for example, without being considered at risk. But this definition may indeed capture a good portion of the households of interest. While Jamasb and Meier find the usual conclusions (fuel poor households are poor, have children or are retired, spend more time at home), they also put high hope in smart meters. By showing current energy consumption, they hope that these meters will trigger behavioral changes and in particular help so far ill-informed households manage better the available energy and look for energy efficiency. As so often, good information goes a long way in managing scarcity.

Education for gifted students: all for nothing?

Not every kid progress at the same pace through school, this is why some occasionally need to repeat their grade. How to handle gifted children is more controversial. Should they be allowed to skip a grade? Should they be offered special classes? Or should they simply follow the normal stream at the risk of getting bored? A good argument for devoting additional resources to them is that they will likely be the future leaders and entrepreneurs, and those are deemed to be the engines of growth.

Sa Bui, Steven Craig and Scott Imberman study the issue in the United States. Interestingly, the US has been steering towards channeling additional funding towards lagging students through the "No child left behind" laws, ironically implemented by a Republican administration. Gifted programs suffered from this reallocation, and the question whether this had an impact on the outcomes of gifted children. Comparing fifth-graders who were the last eligible for a gifted student program to those how just missed out, Bui, Craig and Imberman hardly find a difference. The science outcomes are better when looking at a randomization experiment for eligibility to a gifted student magnet school. This may be due that in such schools, classes are at a higher level and teachers may be better (and parents may get more involved). However, students may be suffering from a lower class rank among their peers. So it may all come to a draw. There is no easy solution.

About the bastardization of news

Earlier this week, I have has the "opportunity" to spend significant time in a US hotel room. The town being of little interest, I used my time to get some work done and to watch some TV. There was the opportunity to see two interesting events, on the same day: the press conference of Ben Bernanke and the statement of Barack Obama about the war in Afghanistan. What a huge disappointment both were.

This is not Bernanke's or Obama's fault, though. The big news channel were treating this like an American Idol contest, with personalities (or journalists, what is the difference now anyways) doing instant ratings on how well they perceived the speakers. Which was then followed by an analysis of some random tweets.

The sad truth is that people will form their opinion from this circus. Never mind that Bernanke and Obama are experts in their field, have thought very hard about their issues with a lot of expert advice, these journalists know on the spot what is best and will dismiss without justification any argument by the push of a button.

This brings me back to the idea that Economics needs some way to certify people to separate those who pretend to know something about Economics and those who do. The latter are mostly unwilling to talk in sound bites and instant opinion, thus the media rushes to the pretend economists. And I wonder how many of the journalists I saw judging Bernanke have any degree in Economics, let alone a graduate degree.

Property rights and natural resources

It is a firmly established conventional wisdom that natural resources are best preserved when there are well established property rights. It is the quintessential example of the tragedy of the commons that if everyone is allowed, say, to take water, water will be over-exploited. This wisdom takes, however, a crucial assumption: that once the resources is taken, property rights are well established and uncontestable. What would happen if not?

Louis Hotte, Randy McFerrin and Douglas Wills show that reverting this assumption can have a dramatic impact. Suppose that you took a freely available resource, but that now anyone can contest your ownership of that resource. Depending on the consequences, you may not want to extract in the first place. It thus matters in which way the state is weak. If it is weak in that it gives away rights to natural resources, then there will be over-exploitation. If it is weak in that it cannot enforce property rights in general, and in particular when it comes to bring product to the market, then it is the Wild West and under-exploitation may ensue. Theft is a powerful mechanism to kill markets.

What is a sticky price?

An amazing amount of scholarly effort is devoted to figuring out optimal stabilization policies in developed economies. I am not convinced this effort is well-placed, as fluctuations in developing economies are much larger and long-term trends quickly swamp short-term fluctuations in welfare assessment for developed economies. The last recession in the US may make it worth to look at stabilization though.

Greg Mankiw and Matthew Weinzierl have a piece of rather pedagogical nature trying to convince us that stabilization policy is worthwhile. Their model is essentially the one that is taught to undergraduates: a two-period model with households maximizing intertemporal utility from consumption, a government, and firms that maximize discounted profits. Oddly, firms do not care about the resale value of capital in the second period, which makes investment largely irrelevant. Finally, prices are fixed the first period, but can be changed in the second period.

Beyond the pedagogical merit, can this model be used for serious policy prescriptions, which Mankiw and Weinzierl even quantify? For one, the last recession was sufficiently important that prices and wages actually adjusted down in the short term, which violates the critical premise of the model. Indeed, all what policy tries to do is undo the frictions stemming from price rigidity. Second, when prices do indeed not change in the short-term, it is presumably when it is not worth doing do so, thus policy intervention also does not seem worth it. Of course, it could be that there is a genuine Keynesian lack of demand, but this can be attacked best by dealing with what causes the lack of demand, not by creating artificial demand through government expenses. For the last recession, this would have been easing collateral constraints. Third, the model assumes a money quantity equation, which imposes a constant money velocity. I thought we all had agreed long ago this was a silly assumption.

I really do not understand the point of this paper. After all, as Mankiw likes to say on his blog, all this can already be found in his favorite textbook.

The marital college premium

There are a lot of good reasons to marry an educated partner. Among them is that his/her income is higher, and theory has consistently pointed to the fact that one's own returns to education should be higher. This is known as the supermodularity of the marriage return function: the second derivative of outcomes with respect to both education levels is positive. This implies that the return to education becomes even higher, as the couple's surplus increases even more due to the supermodularity. But how much?

Pierre-André Chiappori, Bernard Salanié and Yoram Weiss use an extract of the US Census to confirm that supermodularity is present is very significant manner. It varies by cohort, though, with in particular younger females seeing stronger returns than young males. This means that women have done better in three dimensions in recent decades: they closes a large part of the wage gap with men, they get a higher marital college premium and they marry better. All this compounds to remarkable progress for women, who also work more and get a larger share of the marital surplus.

Inattention and bank overdrafts

It happens to everyone: you are not careful and despite having sufficient funds, your checking account is drying up at the wrong moment and you incur an overdraft fee from the bank. Oh well, you say, the penalty is somewhat stiff, but bad planning has consequences. But for those who have genuine liquidity problems or those that are really bad at planning, those fees can add up quickly and become substantial. Even on an aggregate level, it is important. Apparently, US banks earn $35 billion a year from overdraft fees, or a staggering $100 per capita.

Victor Stango and Jonathan Zinman study what can make that people avoid those fees. A lot has of course to do with education and self-discipline, thus reminders become an important tool. Indeed, they notice that people who were exposed to information about overdraft fees in surveys are less likely to incur such fees in the next month, by 12%, and this effect builds up over multiple exposures. This works best with those who need it the most: low education and low financial literacy. And as people avoid overdrafts by making fewer transactions, not increasing balances, it indicates they lower their expenses as a reaction to realizing that they may not afford that much spending. In other words, financial and economic literacy are important and should be favored.

Mission drift in microfinance?

Microfinance is based on a very simple principle. The poorest can only improve if they invest, and very small loans may be sufficient to get them started. But conventional banks do not bother with such loans, and informal money-lenders charge horrendous rates. Microfinance step in and lend small amounts, often without collateral in a community-based scheme where one's reputation is sufficient to obtain somewhat reasonable repayment rates. I am not totally convinced this scheme would work without subsidies, but it obviously serves a useful purpose, as long as it does not crowd out the regular financial system.

Beatriz Armendáriz and Ariane Szafarz point out that the latter can become a problem because of mission drift: as microfinance institutions grow, they gradually target larger loans, neglecting their original mission and becoming more like regular banks. This is like car models that grow in size through the years to follow the life-cycle of their drivers. But Armendáriz and Szafarz think that what looks like mission drift could very well be cross-subsidization, and larger and more profitable loans are made to help continue giving small and less profitable ones. The distinction is important, as donors could be put off by mission drift.

Socialist economies smooth better the cycle

Capitalism is often presented as a wild economic system where conditions are harsh as everyone fights for his survival. The fact that economic agents are not sheltered against shocks leads them to be more efficient and possibly protect themselves better against events. Incentives are not as well aligned in a socialist economy, as free-riding is more prevalent and weaker agents may be more likely to survive in such a sheltered system. The endless discussions on which system is better ultimately boil down to preferences about risk tolerance and fairness, and on which system offers higher welfare.

Bruno Amable and Karim Azizi point out that more socialist economies appear to be better at smoothing out business cycles in the aggregate. Indeed, they tend to adopt more readily Keynesian policies, which do smooth somewhat economic fluctuations, France being the prime example. But that does not yet mean these economies are better: while fluctuations are lesser, the average level may also be lower. And fluctuations may be optimal, as we have learned from the real business cycle literature. So the jury is still out.

The daycare assignment problem

Assigning people with heterogeneous preference to medical residency, schools, job candidates or marital partners is a difficult problem, and with the help of the work of Al Roth, we have made much progress in finding optimal systems. More and more situations are uncovered that required a special analysis because some feature requires rethinking the whole process.

John Kennes, Daniel Monte and Norovsambuu Tumennasan study assignments of toddlers in daycares as applied in Denmark. It is special because if the overlapping generation nature of daycares, and the fact that some children get preferential treatment (like previous attendees and siblings). The usual Gale-Shapley algorithm appears to be Pareto-optimal, at least among stable matching algorithms, as in simpler setups, but it is unfortunately not strategy proof and does not Pareto dominate all strongly stable algorithms. For once, another assignment mechanism seems to perform better. But I wonder what would happen when there is rationing in daycares, as is typically the case.

The economic behavior of bees

I find it fascinating that there is also plenty of Economics in the animal kingdom. Two recent papers about bees just caught my attention.

Antoine Champetier studies the interaction of bees and farmers, as bees play an important role in pollination and are thought to be subject to a mysterious decline in numbers. He takes California almonds as an example and builds a model of pollination supply with hive owners and bees that forage. One aspect appears to be rather important: economies of scale in the hive, as larger hives have an easier time regulating the temperature and can devote more time to more aggressive foraging. Champetier formulates a spatial model of foraging and coordination in the bee colony, where energy used and gained by foraging is assessed, as well as time costs in each step of pollen acquisition and storage.

Noam Bar-Shai, Tamar Keasar and Avi Shmida study what makes that a bee departs early or stays longer in a flower patch. Looking at videos, they concluded that bees cannot count, but are rather governed by clues left by odor marks (to prevent revisiting the same flowers) and current foraging success.

Economic education and opinions about free markets

Public opinion about economic policy in France and the United States are very contrasted. In France, free markets are viewed very suspiciously and government intervention is required left and right. In the US, it is about the opposite, the government should stay out of any business and no tax can be justified. I find it very frustrating to talk to people (not economists) from both countries as they seem conditioned to believe steadfastly in their view. In the case of France, I was nice shocked to hear an elected politician claim that social security could easily be fixed by taking the money that "lies" in the banks.

Radu Vranceanu and Jerome Barthelemy try to relate beliefs in economic paradigms and economic education. Through a survey, they asked French Internet users about their knowledge of basic economic principles, their views on pro-market reforms, along with various demographic and education indicators. The survey was linked from a business school's website, so answers come from a population likely to be more interested than average in economic issue, and probably more likely to be open to pro-business reforms than the average French citizen. Still, it is clear that economic literacy is a god predictor of open-mindedness towards free markets. I bet it is just the opposite in the US.

The pitfalls of $1 CEO salaries

CEO how agree to be paid no salary, or a minimal one, are viewed as heroes in media and the public. But in all the cases I know off, they are of course also compensated with stock options and other deferred pay schemes. So does it really make a difference to being paid a substantial salary?

Gilberto Loureiro, Anil Makhija and Dan Zhang find that not everything is rosy abut these $1 CEOs: They tend to be overconfident and thus expect to have very high compensation in the future. As a consequence, they try to deflect future criticism about their earnings by putting on an angel face now. Also, their overconfidence implies that shareholders do not fare well with them, probably the reason institutional investors avoid them. In other words, be wart of $1 CEOs!

What is the value of research?

What is the value of the research we do? The typical way we have to evaluate the impact of research is to count citations, and possibly weigh them in some way, in Economics and any other sciences (except maybe where patents are relevant). But this only evaluates how the research output is viewed within a narrowly defined scientific community. The contribution to social welfare is an entirely different beast to evaluate.

Robert Hofmeister tries to give research some value. The approach is to consider the scientific process through cohorts, where each wave provides fundamental research as well as end-applications based on previous fundamental research. A particular research results thus can have a return over many generations. It is an interesting way to properly attribute the intellectual source of a new product or process, but the exercise is of little value if it is not possible to quantify the social value of the end-application. Indeed, Hofmeister goes back to using citations in Economics for a data application, which is equivalent to evaluate research only within the scientific community. In terms of the stated goal of the paper, we are back to square one. In terms of getting a better measure of citation impact, this is an interesting application of an old idea. And the resulting rankings of journals and articles look very much like those that are already available.

The high welfare cost of small information failures

Are stock markets efficient in the sense that stock prices reflect all available information? This question has preoccupied finance lately as many have started to doubt the efficient market hypothesis during the latest crisis. One critical aspect of this is whether current tests of the hypothesis actually give an accurate picture, and if not whether this matters in a significant way.

Tarek Hassan and Thomas Mertens
claim that it is possible for stock markets to aggregate information properly, that small errors at the household level can accumulate and amplify if these errors are correlated, and that the welfare consequences can be substantial even if the initial errors were small. This cost emerges for a portfolio misallocation due to the higher volatility of stock prices. To get to such a result, they take a standard real business cycle model, add to it that households get a noisy private signal about future total factor productivity. They then look at the stock market for additional information to form expectations. If you allow households to be on average more optimistic than rationality in some state, and more pessimistic in others, you get the above results. Interestingly, Hassan and Mertens show that households face little incentives to correct individually for these small common errors (0.01% of average consumption), but collectively the consequences are large (2.4%). Talk about an amplification.

Pollution has an impact on worker productivity

Pollution regulation is typically cast as a game between citizens and firms, the first suffering the consequences of pollution while the second are the origin of the pollution. In such a case, there is no incentive for firms to abate pollution, and the government has to mediate. But could a case be made that firms should be willing, individually or collectively, to reduce pollution. One way can be green labeling, which could increase the demand for their products. Another would be if firms realize pollution has an impact on their on productivity or on the labor supply.

Joshua Graff Zivin and Matthew Neidell take the worker productivity angle by using a dataset of dairy farm workers from a large farm in the Central Valley of California. In particular, they look how ozone levels impact the output of piece rate workers. At it is substantial. For example, a 10 ppb reduction of ozone increases productivity by 4.2%, noting that the standard deviation of ozone levels is 13 ppb. And if you object that some of the workers fall under minimum wage law and may not exert the right effort, be reassured, the authors took that into account. In addition, this impact happens even when the ozone level is well below the current national standards. Realizing this, industry should be more willing to accept the suggested tightening of pollution standards for ozone, and for nitrogen oxides and volatile organic chemicals that are the source of ground-level ozone.

Does it make sense to subsidize biofuels?

Ina relatively short time, biofuels have become remarkably popular, especially as an additive to regular petroleum based fuel. This is at least in part due to massive subsidies from the US to fuel and corn producers. As biofuels compete with food, this has lead to major price increases for corn and sugar, with adverse consequences for importing countries. This begs the question: is it actually a good idea to subsidize biofuels? I mentioned previously that it is preferable to tax other energy products rather than subsidize alternative energies (1, 2), but let us revisit this issue.

Subhayu Bandyopadhyay, Sumon Bhaumik and Howard Wall use a general equilibrium trade model and confirm that if there is a Pigovian tax on conventional fuels, subsidies are not needed. But if the Pigovian tax is not available or too low (as is the case in the US), then a subsidy for biofuels makes sense, But if the country in question is large, there are other implications through increased worldwide demand for food. In that case, a food exporter wants to subsidize biofuels and tax conventional fuels. A food importing country would only want to subsidize biofuels if the pollution reduction effect is large enough.

Hector Nuñez, Hayri Önal, Madhu Khanna, Xiaoguang Chen and Haixiao Huang look more specifically at the interaction of policies in the US and Brazil, the two largest producers of biofuels. Indeed, the US imposes a special tariff on the importation of biofuels, in particular the more advanced sugarcane based one from Brazil. Brazil is also the largest producer and exporter of beef. The paper uses a multi-country, multi-good model, unfortunately with a partial equilibrium, but it takes into account possible crop rotations and different categories of land. It concludes that eliminating the tariffs would significantly reduce biofuel production in the US, with the latter importing biofuels from Brazil and exporting corn. While this reduces producer welfare compared to the status quo, it increases consumer welfare. Given the political system in the US, guess what will happen.

Shortsightedness and tariffs

International trade theory is in large part about optimal trade theory, yet it is incapable to explain the observed level of tariffs. While under rather general circumstances theory will tell you that zero tariffs will improve general welfare, once you take into account that governments threaten and negotiate in a Nash equilibrium, tariffs should be at about 30%. They are generally far below that. It is a big challenge to explain the difference.

Mario Larch and Wolfgang Lechthaler argue that all that is needed is for trade theory to finally catch up with the rest of economics and use some dynamics. Specifically, transform the problem into a dynamic Nash equilibrium, take into account transition paths, and you get some realistic numbers if you assume that the negotiating politicians are short-sighted, which is certainly not far from the truth. This is important because the various transitional effect of a tariff change take different times. Indeed a decrease in tariffs has a faster and positive impact on consumption through an immediate increase in consumption. A counter-effect through the closing of inefficient firms takes much longer. Impatient politicians discount heavily the latter.

Should voting be compulsory?

Should one force people to vote? While there are clear incentives for people not to vote because it is very unlikely their individual vote would matter, there may be a social benefit to make sure that everyone, or at least many people, votes. Clearly, public decision-making is difficult when people do not voice an opinion. But imagine you are forced to vote, how should you vote? Selfishly, or for the public good? And how should that public good be defined? Your family, the neighborhood, your clan, your country? Indeed, if you force someone to vote, you must have an idea for what purpose you impose this.

Dan Usher tries to make sense of all this focusing on the idea of the duty to vote, the duty being an unenforceable obligation. The paper is impossible to summarize without making a massacre of it, so I will abstain. It is full of ideas on how to think about the duty to vote, abstention, and mandatory voting. Read it if you are interested.

Seat belts lead to safer driving

A classic example of the law of unintended consequences is how seat belt laws gave reasons to drive more dangerously, as car drivers feel more secure. This idea has been popularized by Sam Peltzman and several follow-up studies.

Yong-Kyun Bae puts some serious doubts in this results by pointing out that all these studies were based on aggregate data. Using individual data, which allows to exploit individual characteristics, as well as the circumstances of accidents. And once you control for these factors and exploit cross-state variations of how seat-belt laws became more or less stringent in the last decade, it appears more stringent laws make people drive more carefully. Indeed, pedestrians are getting safer. If this result stands, the challenge is to explain it: do tougher seat-belt laws signal stronger enforcement of other traffic laws? In particular, as Bae suggests, these laws may come in tandem with cell-phone and texting-while-driving laws.

Risk-free rate tax deductions

The Norwegian shareholder tax is rather peculiar in that it allows the deduction of risk-free interest income, thus only taxing the risky portion of capital income. This is rather counter-intuitive, as one usually wants to encourage risk-taking in the form of venture capital or plain entrepreneurship. But the idea in Norway was that this would make financing of firms neutral with respect to the source of funds.

Jan Södersten and Tobias Lindhe argue this line of reasoning is not appropriate for an open economy like Norway and 56% foreign ownership. Indeed, one needs to understand as well who is investing. Indeed, taxes are capitalized differently by different people. Indeed, for an economy that is so open, returns are largely determined on international markets, What is then determinant for Norway is the after-tax return, and this is where new distortion enter the picture: large firms are financed on international markets, and the after-tax rate is set abroad. Small firms that finance themselves domestically have provide similar after-tax returns, but domestic investors face different tax rules than their foreign counterparts. This is where new distortions can enter, and severe under-investment in domestic firms could be the consequence. But for a rather closed economy, this seems a good idea, especially as it is a neat way to prevent under-reporting of income.

Minimum wage and tax evasion

While the minimum wage is seen by many as an easy way to prevent poverty, it has its pitfalls. Apart from the fact that it may increase unemployment, it may lower wages and attract more immigrants. Now add to this that minimum wages may decrease disposable income and thus consumption.

Mirco Tonin looks at the case of a country with a significant underground economy. As only declared labor income is taxed, introducing a minimum wages means that everyone must declare at least the minimum wage as income. For at least some people this will reduce disposable income. Now increase that minimum wage, then everyone who was declaring such an income has to pay more taxes. Is this significant? Tonin looks at Hungary where there was a significant increase in the minimum wage in 2001 and it is believed half of those declaring minimum wage on their tax return actually earn more. Looking at the gap between consumption and income on household data, a common way to identify underground income, he finds that the effect on consumption was quite significant for those who were affected by the minimum wage hike.

What is a macroeconomic model?

Critics have had a field day the past couple of years claiming that Economics is not up to the task because its models are too abstract. Macroeconomics has been especially affected because the trigger of the bandwagon was a macroeconomic event, the now Great Recession. I have discussed a few bad attempts at criticism, which were usually bad because ill-informed and because they could not offer any viable alternative.

The latest salvo comes from Hashem Pesaran and Ron Smith. They have several arguments. The first is that macroeconomic modeling of the DSGE brand insists too much on internal consistency and should allow more degrees of freedom to fit the data. Pesaran and Smith should first specify what the goal of the model is before criticizing the approach. If it is short-term forecasting, then go ahead with a purely statistical approach on macro data. If you want policy advice, you need something that withstands the Lucas Critique, and strong micro-foundations is then the way to go. But without a given purpose, any criticism is moot.

Pesaran and Smith, given their track record, are of course strong advocates of purely statistical methods. Throw every possible series in a regression, and see what sticks. I am not saying this cannot be useful, it allows to establish relationships in the data and I regularly report on such results, but this does not allow you to explain things. For this, you need some structure and theory provides you that. This brings me to the title of this post. There appears to be some disagreement about the meaning of the word "model." To me, model is a set of relationships established by theory that can then be used on data, for policy experiments, etc. For Pesaran and Smith, a model is a set of aggregate data series that are used in a statistical analysis of some kind (VAR, non-parametric, etc.). If we cannot agree what we are talking about, of course there will be endless and fruitless discussions.

For example, they are not the first to criticize DSGE models for failing to include housing, finance and the external sector. Well, models (the way I see them) are abstractions, and you do not want to include everything them, or you cannot understand, interpret or do something useful with. It is so across all sciences. You build a model to answer a particular question, and you give it the necessary bells and whistles. The fact that most DSGE models did not include housing and bank liquidity is not a failure of DSGE modelling, it is a failure of recognizing what questions could be important in the future and this is damn hard to do properly.

Pesaran and Smith's solution to what they call the straightjacket of DSGE is to throw all these missing variables in a regression. Essentially, they want to bypass the discipline that theory imposes by letting the data speak. Again this is OK if you want to explore and find relationships, but this is not going to be very useful if you want to explain what is going on. Specifically, they advocate using vector autoregressions (VAR). As they complain that DSGE use representative agents when heterogeneity matters, they call for the use of data from several countries in the VAR, a rather strange argument, but I suppose this is because they are limited to aggregate data (and they neglect all the DSGE models using household level data...). In a statistical sense, the big problem is now that one quickly runs out degrees of freedom, as one has only so many time periods, and every additional variable eats degrees of freedom at a quadratic rate (times the number of lags). The other problem is that interpreting the resulting errors ("shocks") becomes difficult. One is then limited to vague notions like demand and supply shocks, much like in factor analysis. But at least Pesaran and Smith acknowledge that theory can be useful in selecting, say, long-term restrictions.

PS: I gave much of the same arguments in the discussion of a paper by David Hendry. Pesaran appears to be more knowledgeable of DSGE and is more willing to use theory to guide empirics. Unfortunately, Pesaran has the same habit of abusing self-citations, 12 out of 32.