At the end of a long post about obesity--part of an ongoing debate she has been having with a number of other bloggers--Megan McArdle considers the possibility of government action and writes:

Ultimately, the answer to "what could it hurt"? is that all actions have costs, which you cannot assume away on the grounds that those costs don't interest you.  But they should interest you, because not least among those costs is the simple fact that the government cannot do everything well.  Making all sorts of changes in the name of obesity means not making others that might be more important, because we have limited political and bureaucratic bandwith.  Do you want obesity intervention, cap and trade, or health care reform?  You may not be able to have any of them.  But you probably can't have all three.  And if you did, you'd make it more likely that the government would screw all of them up. [Italics Hers]

You might think that, as a self-described "pessimistic libertarian", McArdle would be arguing that an expanded government mandate would translate into a bigger federal government. But no: Instead she argues that our limitied bureaucratic space will be forced to take on another task. The major problem with this excerpt, however, is that there are so many large claims in such a short paragraph. I see six relatively strong statements here, and none of them are backed up with the least bit of evidence. Do all actions have costs (or at least costs worth noticing)? Does enacting changes in obesity policy mean not enacting other more important policy changes? Is there limited bandwith? Can we really not have a cap-and-trade bill, health reform, and obesity intervention? And, most importantly, does enacting all three sets of policies make it more likely that government will screw them up? Is that generally true of goverment actions? The reason I am asking these questions--rather than answering them--is that I genuinely do not have the answers. It is very tempting to speculate, but even speculation should at least have some evidence marshalled in its favor.

--Isaac Chotiner