Noah Smith has a post on the failure of macro theory to predict the crisis. He concedes that DSGE models did very badly on this score, but, he continues, “There are no other models out there that did forecast the crisis” and there is no better alternative.

The word “better” is important here because some “angry heterodox” people have pointed Smith to at least one alternative—Wynne Godley’s Seven Unsustainable Processes—that had in fact predicted the crisis. However, Smith rejects this as “basically just chartblogging” [emphasis added]. He writes that

Yeah, sure, if you put out hand-wavey reports saying “capitalism sux, there’s gonna be a crash!” every year or two, you’re eventually going to be able to say “see, I told you so”. But that’s no replacement for real modeling.[sic]

First of all, there is nothing wrong with chartblogging. In fact, Noah Smith is a chartblogger—an excellent one.

Having said that, is Godley’s argument just hand-wavey-capitalism-sux-chartblogging or is there something more to it (perhaps even some real modeling)?

To begin with, Godley’s argument in the Seven Unsustainable Processes (which is a policy paper) is based on his theoretical work. Godley was one of the major proponents of what is today called Stock-Flow Consistent methodology. Some of his books and his writings (with real models and everything) are here, here, and here.

(The other major proponent of this methodology was James Tobin. His lecture when he was awarded the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel was a manifesto of this methodology.)

Based on this theoretical work, in the 1990s Godley built a more policy-oriented macroeconomic model at the Levy Economics Institute. The simulations in the Seven Unsustainable Processes were produced with this model (and are thus far from chartblogging).

To understand the argument of the Seven Unsustainable Processes we need to keep two things in mind. First of all, the analysis is Keynesian, so it is aggregate demand that drives output, employment, and growth. These Keynesian results do not stem from imposing rigidities on an otherwise supply-side neoclassical model.

A second important piece of the analysis is a simple macroeconomic identity that comes straight from the National Accounts:

(Private Expenditure – Income) + (Government Expenditure – Income) = Current Account Deficit

In other words, the sum of the private sector and government sector deficit is always equal to the current account deficit. Accounting consistency requires that the flows expressed in the three balances accumulate into related stocks. For example, if the private sector is running a deficit, that will (ceteris paribus) tend to decrease its net worth and increase its debt and debt-to-income ratio.

The examination of these financial balances in relation to income (or GDP) is important because it gives clues about (i) central structural characteristics of an economy, (ii) which component of demand is driving growth, and finally (iii) what net assets/income ratio for each sector is implied from the current situation.

Having said this, we can now go to the crisis and the question of whether Godley actually predicted it or not. continue reading…