John McCain's campaign recently released a letter signed by 90 economists, titled "100 Economists Warn That With Current Weak Financial Conditions Barack Obama's Proposals Run A High Risk Of Throwing The US Into A Deep Recession'".
I'll leave aside the McCain campaign's inability to mark to acutal sample size and note that the letter includes several eminent scholars. It also includes some folks not known for simultaneous independence and influence; entertaining examples include chief McCain economic policy adviser Doug Holtz-Eakin (I guess they needed him just to get to 90), American Enterprise Institute President Chris DeMuth, and former Secretary of State George Shultz. As an influential friend wrote me earlier today, "in the context of the NBER or scott Adams surveys....[t]his is just an existence proof--there exist  economists who are pro- McCain." For more on those surveys, click here and here.
In the meantime, Greg Mankiw explains why he didn't sign the letter:
Some blog readers may ask, why didn't I sign? I am not particularly fond of Obama's proposed tax hikes or his apparent retreat from free trade. (See this article of mine.) But I thought the statement in the group letter that "his proposals run a high risk of throwing the economy into a deep recession" was a tad too hyperbolic for my tastes.
I disagree with plenty, though certainly not all, of what Mankiw has written about public policy. And I think anyone who would agree to be George Bush's chief economic adviser after having a chance to watch him in action ought to develop a different associational threshold.
But I've noticed that as the McCain campaign has gotten loopier, Mankiw has both blogged about the presidential campaign less and made statements like the one above. Kudos to Mankiw for calling out his side in this case.