Regulation and the financial crisis

Various people have argued that the current crisis has been the result of a lock of regulatory oversight, that basically allowed banks to do silly things. I fail to be convinced about this argument for the simple fact that the only financial entities that have run into trouble were regulated ones, and the unregulated hedge funds, while obviously facing losses, are still in business without outside help. But it is still worthwhile thinking whether regulation is at an optimal level.

Joshua Aizenman provides a rather intuitive model of banking regulation: regulation reduces the risk of a crisis, but the perceived lower risk reduces support for regulation. Thus, one would always have under-regulation and even no regulation after sufficiently long, crisis free spell. This under-regulation is exacerbated by the fact that the public typically does not observe (or understand) the regulator's efforts. Of course, there is over-regulation immediately following a crisis, especially if it is very costly. Bayesian updating will do that to you. How to prevent these issues? Essentially the same way one prevents the inflation bias of a central bank: independence, transparency and predefined goals.

That said, and I mentioned it above, under-regulation may not necessarily be the trigger of the current crisis. What is sure, however, is that additional regulation is certainly not necessary now. All the activities that people have decried (under-priced sub-prime lending, over-leveraging, etc.) have disappeared without regulatory intervention. Such is the market...