Well, in a different chapter Madrick recalls Milton Friedman’s dictum that economic models should be judged not by the realism of their assumptions but by the accuracy of their predictions. This lets general equilibrium off the hook, sort of. But has the proposition that free markets get it right ever been vetted for predictive accuracy? Of course not. Friedman’s own polemics on behalf of free markets consist mainly of “assertions based on how free markets may work according to the Invisible Hand,” Madrick writes, with hardly any evidence presented that they actually work that way.

In other words, economists arguing for free markets and limited government try to have it both ways: They claim that their doctrine is a deep insight derived from first principles, but dismiss as irrelevant the overwhelming evidence that these assumed principles don’t hold in practice.

Matters are even worse when it comes to the performance of financial markets. Here the proposition that markets should get it right — that major speculative bubbles can’t happen (bad idea No. 5) — doesn’t just depend on conditions that clearly don’t hold in practice, but is directly contradicted by evidence on herd behavior and excess volatility. Yet “efficient markets theory” has maintained its academic dominance. Eugene Fama of the University of Chicago, the father of efficient markets, still denies that financial bubbles even exist — and last year he shared a Nobel in economic science.

Still, all of these failings of mainstream economics were obvious long before the 2008 crisis. What has really come as news is the seeming inability of economists to agree on a policy response to mass unemployment. And here is where my quibbles with Madrick get louder.

No. 2 on Madrick’s bad idea list is Say’s Law, which states that savings are automatically invested, so that there cannot be an overall shortfall in demand. A further implication of Say’s Law is that government stimulus can never do any good, because deficit spending by the public sector will always crowd out an equal amount of private spending.

But is this “mainstream economics”? Madrick cites two University of Chicago professors, Casey Mulligan and John Cochrane, who did indeed echo Say’s Law when arguing against the Obama stimulus. But these economists were outliers within the profession. Chicago’s own business school regularly polls a representative sample of influential economists for their views on policy issues; when it asked whether the Obama stimulus had reduced the unemployment rate, 92 percent of the respondents said that it had. Madrick is able to claim that Say’s Law is pervasive in mainstream economics only by lumping it together with a number of other concepts that, correct or not, are actually quite different.