Dylan Matthews had a piece on Modern Monetary Theory in the Washington Post yesterday that featured Levy Institute scholars James Galbraith and Randall Wray.  WaPo also put together a “family tree” that displays some Post Keynesian and New Keynesian lineages.

The piece has been bouncing around the internet, first with some supportive comments by Jared Bernstein (he critiques the political viability of being able to control inflation through tax increases and insists on the long-term challenge we face due to rising health care costs).  Both Dean Baker and Kevin Drum ask what’s so special about MMT, with Drum suggesting a focus on views about inflation.  According to Drum, this is the central question:

So should we focus instead on a genuine target of 4% unemployment, reining in budget deficits only when we fall well below that? That depends a lot on what you think the productive capacity of the country really is, and the mainstream estimate of NAIRU, the highest unemployment rate consistent with stable inflation, is around 5.5% right now. If that’s the right estimate, then you could argue that we’ve been doing OK for the past few decades. But if full employment is really more consistent with an unemployment rate of 4%, then we’ve been wasting an awful lot of productive capacity for nothing.

… Of course, you might also want to consider MPT, or Modern Petro-Monetary Theory. Rather than asking what level of economic growth kicks off unacceptable inflation, it asks what level of economic growth kicks off an oil price spike that produces a recession and higher unemployment. I have to admit that I increasingly think of the economy in those terms these days.

In comments at Mother Jones, Galbraith engages with Drum’s “MPT” point:

Kevin – your instinct on the oil price is on target, in my view.  The inflation threat that we face doesn’t come from deficits or high employment — it comes from the cost and price of energy.  But managing this is not within the competence of the Federal Reserve.

I have been trying to call attention to this issue for years (it’s in my 2008 book, The Predator State, and in articles written recently with Jing Chen, most recently in the Cambridge Journal of Economics, which contains the following paragraph:

“Our central argument is that stimulus fell short – and would have fallen short even if the amounts had been greater – because increased demand under existing high-fixed cost structures drove, or would have driven, the price of resources too high, too quickly. The constraint on growth was not inflation generated by easy money, but the combination of the rising real marginal cost especially of energy, combined with monopoly control of and speculative instability in energy prices, which together act as a choke-chain on the return to full employment.”

But the endless debate over deficits, debt and quantitative easing tends to obscure this issue — and in public discourse one cannot easily answer questions that are not being asked.  So thanks for making the point, and keep digging at it.