Megan McArdle has a post on government involvement in the economy, focusing on currency controls. While international finance makes my head ache, I think her concluding simile applies to more government regulation situations than just currency:
In general, the more the state intervenes in an economy, the worse that economy performs. Statists argue that this is irrelevant because the market produces some spectacular failures. Indeed it does. But arguing that we should fix it by turning to the State is like arguing that, because modern cancer therapy often fails, we should put a witch doctor in charge of treatment instead of an oncologist.