Anybody interested in the future of mathematical theory in economics should read Cesar Hidalgo’s book Why Information Grows. There are many things to like about this lucid account of the evolution of our scientific understanding of information. One of the most important may be the simplest. It illustrates what it means to think like a physicist. Thinking like a physicist is very different from using such tools from physics as partial differential equations.

If we broaden the frame from mathiness narrowly defined and look for academics who are guided by the norms of politics instead of the norms of science, it is not hard to find examples from both ends of the political spectrum. No matter which end they come from, they can bring science to a halt. If you ever want to reach a scientific consensus about anything–whether wage growth in the UK has been positive or negative, whether England even exists–you will not want to invite either Niall Ferguson or Paul Ehrlich into the discussion.

It might be helpful to pull back from some of the specifics in the instances of mathiness that I’ve cited in recent posts and recap the background motivation, which springs from concern about the interaction between science and politics. I. There are two different styles of discourse–the discourse of politics and the discourse of science. They are supported by different norms about good ethical behavior and acceptable professional conduct. A. Reputation

Dietz Vollrath has a new post that goes a long way toward clarifying the battle lines in the fight over the foundations of growth theory. If you haven’t read it, go read it now, then come back. Any attempt I might make to summarize it here will only add noise. The trilemma he lays out is crystal clear. He acknowledges conversations with Pietro Peretto, who apparently deserves some of the credit for the distilled clarity of the post.

1. Marshallian Intuition One type of reaction involves a recitation of some Marshallian intuition about rents or quasi rents and a request for clarification about what this intuition misses. My suggestion is that if you are stuck, try approaching the problem from a new angle. In this case, a good way to do so is to work through the logic of the proof based on Euler’s Theorem and try to see whether its assumptions fit the example you are considering.