Social Science Smackdown Week!

There have been an awful lot of high-profile battles going on in the blogosphere lately. And I'm not talking about the typical blogger-vs.-blogger spats. I'm talking about big-shot social science Ph.D.s going at it hammer-and-tongs over issues directly related to public policy. A breakdown:

-- Richard Posner vs. Alan Greenspan on whether Greenspan deserves some blame for the economic crisis, with commentary by Megan McArdle (she calls this round for Posner).

-- Scott Sumner vs. Brad DeLong and Paul Krugman on the utility of models of asset-price bubbles. Of course, Sumner has been fighting with Krugman practically non-stop since joining the blogosphere.

-- A real-live bet (for money!) between Bryan Caplan and John Quiggin over U.S. vs. E.U. unemployment rates over the next decade. I previously covered this here.

-- William Easterly vs. Jeffrey Sachs, and Dani Rodrik, and Paul Collier, all on different aspects of development policy. Plus a bonus: Dambisa Moyo goes after Sachs, too! It's usually not nice to gang up, but then again, Sachs started it.

-- Robin Hanson vs. Andrew Gelman on the signaling motivations of the approaches conservatives and libertarians take to public policy, with a cameo by Tyler Cowen whose contribution was one pithy line: "don't forget the villains also".

Whew! I must say, I've tried to pick a few fights in recent days but nobody ever notices me (except dear Emmanuel, who is always willing to argue in favor of the proposition that I am either silly or stupid). But for fun, here's my scorecard on the above arguments:

1. Posner vs. Greenspan is a draw; Greenspan certainly bears some responsibility for the consequences of his actions, however it is hard to imagine anybody else in the same position doing much better (as evidenced by the fact that Greenspan had few critics until last Fall). I also think that Posner over-states his case.

2. Sumner vs. Krugman/DeLong goes to Sumner; even if Krugman and DeLong succeed in fitting past data onto a model, its utility going forward is probably close to nil.

3. I'd take Caplan's side over Quiggin's in their bet, but I think it'll be very close. Caplan's first proposal was pretty obviously skewed in his favor, which is why Quiggin forced a compromise. The new terms strike me as fair and much more interesting.

4. Easterly vs. Sachs goes to Easterly; Easterly vs. Rodrik is probably a draw; Easterly vs. Collier goes to Collier.

5. Hanson vs. Gelman goes to Gelman.