You remember the dialogue:
Queen: Slave in the magic mirror, come from the farthest space, through wind and darkness I summon thee. Speak! Let me see thy face.
Magic Mirror: What wouldst thou know, my Queen?
Queen: Magic Mirror on the wall, who is the fairest one of all?
Magic Mirror: Famed is thy beauty, Majesty. But hold, a lovely maid I see. Rags cannot hide her gentle grace. Alas, she is more fair than thee.
I was reminded of this particular snippet from Snow White and the Seven Dwarfs while reading the various defenses of contemporary macroeconomic models. Mainstream macroeconomists failed to predict the most recent economic crisis, the worst since the Great Depression of the 1930s, but, according to them everything in macroeconomics is just fine.
There’s David Andolfatto, who argues that the goal of macro models is not really prediction; it is, instead, only conditional forecasts (“IF a set of circumstances hold, THEN a number of events are likely to follow.”). So, in his view, the existing models are mostly fine—as long as they’re supplemented with some “financial market frictions” and a bit of economic history.
Mark Thoma, for his part, mostly agrees with Andolfatto but adds we need to ask the right questions.
we didn’t foresee the need to ask questions (and build models) that would be useful in a financial crisis — we were focused on models that would explain “normal times” (which is connected to the fact that we thought the Great Moderation would continue due to arrogance on behalf of economists leading to the belief that modern policy tools, particularly from the Fed, would prevent major meltdowns, financial or otherwise). That is happening now, so we’ll be much more prepared if history repeats itself, but I have to wonder what other questions we should be asking, but aren’t.
Then, of course, there’s Paul Krugman who (not for the first time) defends hydraulic Keynesianism (aka Hicksian IS/LM models)—”little equilibrium models with some real-world adjustments”—which in his view have been “stunningly successful.”
And, finally, to complete my sample from just the last couple of days, we have Noah Smith, who defends the existing macroeconomic models—because they’re models!—and chides heterodox economists for not having any alternative models to offer.
The issue, as I see it, is not whether there’s a macroeconomic model (e.g., dynamic stochastic general equilibrium, as depicted in the illustration above, or Bastard Keynesian or whatever) that can, with the appropriate external “shock,” generate a boom-and-bust cycle or zero-lower-bound case for government intervention. There’s a whole host of models that can generate such outcomes.
No, there are two real issues that are never even mentioned in these attempts to defend contemporary macroeconomic models. First, what is widely recognized to be the single most important economic problem of our time—the growing inequality in the distribution of income and wealth—doesn’t (and, in models with a single representative agent, simply can’t) play a role in either causing boom-and-bust cycles or as a result of the lopsided recovery that has come from the kinds of fiscal and monetary policies that have been used in recent years.
That’s the specific issue. And then there’s a second, more general issue: the only way you can get an economic crisis from mainstream models (of whatever stripe, using however much math) is via some kind of external shock. The biggest problem with existing models is not that they failed to predict the crisis; it’s that the only possibility of a crisis comes from an exogenous event. The key failure of mainstream macroeconomic models is to exclude from analysis the idea that the “normal” workings of capitalism generate economic crises on a regular basis—some of which are relatively mild recessions, others of which (such as we’ve seen since 2007) are full-scale depressions. What really should be of interest are theories that generate boom-and-bust cycles based on endogenous events within capitalism itself.
With respect to both these issues, contemporary mainstream macroeconomic models have “stunningly” failed.
I imagine that’s what the slave in the magic mirror, who simply will not lie to the Queen, would say.