Let’s be clear about what we mean by (substantive) theory

I’ve had a few discussions recently about how to think about substantive theory. What should we be looking for?

A proposal I like comes from a passing remark by Dixit in Lawlessness and Economics (2004, p. 22; link):

The aim of theory should be to construct a collection of models that is sufficiently small to be remembered and used, and covers a sufficiently large portion of the spectrum of facts.

This is not so different than Clark and Primo’s proposal of theory as map-like working approximations that we use for guidance in addressing particular problems (link). I like their view and it’s one that I endorse when discussing how theory and empirics interact in the recent JOP piece (link; ungated).

Personally, I don’t use the word “model” lightly, and I suspect that Dixit doesn’t either. When I use it I do in fact mean a formal model. An important benefit of a formal model, to me, is its low semantic ambiguity, at least when compared to verbally stated theories. There is nothing more frustrating than debating the internal consistency of a theory when everyone has a different interpretation of the terms. Of course, formalization does not solve the problem of relating the theory back to reality, but then this issue of operationalization is separate.