Arnold writes:

With one exception, I think there is nothing that the public can look for in terms of a signal about economists. The best thing is to force economists to explain their arguments clearly in layman’s terms, and then to evaluate the arguments on their merits. That means you have to know enough about economics to be able to distinguish a compelling economic argument from demagoguery.

But he gives up too easily. Besides the heuristic Arnold mentions (seeing whether people break ranks with their own ideology), there are several others:

  • Compare credentials. If the advocate of X teaches at Harvard, and the opponent of X teaches at a community college, this raises the probability that X is true. (And yes, this means that all else equal, you should side with Dani Rodrik against me. Fortunately, all else is not equal).
  • Adjust for social sanction. If X is a popular, crowd-pleasing conclusion, you should expect this to make smart defenders of X more abundant – regardless of the truth of X. You should therefore hold the defenders of such views to higher standards.
  • Check the bets. If only one side is willing to bet hard cash, that side is probably right.
  • You don’t have to take a side. If you really have no idea who to believe, remain agnostic. In fact, it would be much better for the world if the less-informed practiced Swiss neutrality, leaving the well-informed to guide policy.

I could go on. None of these heuristics is perfect, but they’re all better than nothing. Who’s got some more?