More on today's apparent theme, at least for the moment, economic methodology. This is from Simon Wren-Lewis:
Microfounded and other Useful Models, mainly macro: This title harks back to one of the books that have influenced me most: Blanchard and Fischer’s Lectures on Macroeconomics. That textbook was largely in the mould of modern microfounded macroeconomics, but chapter 10 was not, and it was entitled ‘Some Useful Models’. One of their useful models is IS-LM.
The role of such models in an age where journal papers in macro theory are nearly always microfounded DSGE models is problematic. Paul Krugman has brought this issue to the forefront of debate, starting with his ‘How Did Economists Get It So Wrong?’ piece in 2009. His view has been recently stated as follows: “That doesn’t mean that you have to use Mike’s [Woodford] model or something like it every time you think about policy; by and large, ad hoc models like IS-LM are actually more useful, in my judgment. But you probably do want to double-check your logic using fancier optimization models.”
This view appears controversial. If the accepted way of doing macroeconomics in academic journals is to almost always use a ‘fancier optimisation’ model, how can something more ad hoc be more useful? Coupled with remarks like ‘the economics profession went astray because economists, as a group, mistook beauty, clad in impressive-looking mathematics, for truth’ (from the 2009 piece) this has got a lot of others, like Stephen Williamson, upset. I think there are a lot of strands here, many of which are interesting.
The issue I want to discuss now is very specific. What is the role of the ‘useful models’ that Blanchard and Fischer discuss in chapter 10? Can Krugman’s claim that they can be more useful than microfounded models ever be true? I will try to suggest that it could be, even if we accept the proposition (which I would not) that the microfoundations approach is the only valid way of doing macroeconomics. If you think this sounds like a contradiction in terms, read on. ...[continue reading]...
I don't disagree, but my view on this is a bit different, e.g. see the post New Old Keynesians? (though the claim that the newer models weren't built to answer the important questions we needed to confront when the crisis hit is not as valid today -- much of the current work in macro is intended to fix this problem).