Tuesday, March 1, 2011

Is it OK to disregard Macroeconomists? - Robin Hanson versus Robin Hanson

I don’t always agree with Robin Hanson on the Overcoming Bias blog, but I (very) often find him interesting.
Recently, Vladimir M  trashed macroeconomics for being a discipline dealing with ideologically charged questions and lacking clear research directions:
Even a casual inspection of the standards in this field shows clear symptoms of cargo-cult science: weaving complex and abstruse theories that can be made to predict everything and nothing, manipulating essentially meaningless numbers as if they were objectively measurable properties of the real world, experts with the most prestigious credentials dismissing each other as crackpots.
Hanson counters that
If ideology severely compromises others’ analysis on this subject, then most likely it severely comprises yours as well.  You should mostly just avoid having opinions on the subject.  But if you must have reliable opinions, average expert opinions are probably still your best bet.  (Unless of course you have a prediction market available. :) )
My first thought was that this sounds like a tiresome and difficult task. In a field as polarized as macroeconomics, estimating “average expert opinions” is not a simple matter (all economists? all AEA members? all Nobel Laureates? do we include both the DSGE models crowd, the Neo-Keynesians, Austrian Business Cycle theorists, New Keynesians, institutionalists? Only tenured professors – in the US only or globally?) And the choice of population is important when views are polarized: Changing the population you consider will have a big impact on the “average” opinion.
My second thought is that we might not need to bother. There is a different defence of Vladimir M from an earlier version of Robin Hanson.  Writing on the strong selection bias in economics, he noted that you can justify any conclusion or answer you want by selecting from the many assumptions and models that are available. He wrote that
we [economists] are so capable of choosing further assumptions to get the answers we want that outsiders can’t gain much policy advantage from our further insight.
 That sounds about right to me, given the current state of macro.