"Ricardo's Difficult Idea"

The usefulness of mathematical modeling, a subject brought up by Krugman in this commentary, seems to have struck a bit of a chord. So let me follow up with one or two more commentaries from Krugman on this topic. Let's start with this defense of both economic models and Ricardo's theory of comparative advantage (this is fairly long -- Section 4, "The Two Cultures," deals directly with mathematical modeling):..more>>