Comment on Krugman's "The Fall and Rise of Development Economics"

This was assigned reading in my Economic Development class.  Krugman won the most recent Nobel Prize for Economics and is an influential author.  One can see why from this example.  He is certainly good at communicating his economic ideas.  This article deals with methodology and I found it especially interesting.  Methodology in economics is a topic that interests me and I have generally wrestled with how mathematical the profession has become.  Modern theories and models must be advanced using a model based on mathematical tools.  I admit that I have been sceptical of this at times.  This article wrestles with this question and I was especially struck by this statement:

"If you look at the writing of anyone who claims to be able to write about social issues without stooping to restrictive modeling, you will find that his insights are based essentially on the use of metaphor. And metaphor is, of course, a kind of heuristic modeling technique.

In fact, we are all builders and purveyors of unrealistic simplifications. Some of us are self-aware: we use our models as metaphors. Others, including people who are indisputably brilliant and seemingly sophisticated, are sleepwalkers: they unconsciously use metaphors as models."

A well-written and worthy defense of mathematical modeling in social sciences.