A new paper that was presented last week at the 2017 U.S. Monetary Policy Forum has garnered, rightly, a lot of attention. The paper, entitled “Deflating Inflation Expectations: The Implications of Inflation’s Simple Dynamics,” has spawned news articles such as “Research undercuts Fed’s two favorite U.S. inflation tools” (Reuters) and “Everything the Market Thinks About Inflation Might Be Wrong,” (Wall Street Journal) the titles of which are a pretty decent summary of the impact of the article. I should note, because the WSJ didn’t, that the “five top economists” are Stephen Cecchetti, Michael Feroli, Peter Hooper, Anil Kashyap, and Kermit Schoenholtz, and the authors themselves summarize their work on the FiveThirtyEight blog here.

The main conclusion – but read the FiveThirtyEight summary to get it in their own words – is that the momentum of the inflation process is the most important variable (last year’s core inflation is the best predictor of this year’s core inflation), which is generally known, but after that they say that the exchange rate, M2 money supply growth, total nonfinancial credit growth, and U.S. financial conditions more broadly all matter more than labor market slack and inflation expectations.

Whoops! Who farted in the Fed’s elevator?

The Fed and other central banks have, for many years, relied predominantly on an understanding that inflation was caused by an economy running “too hot,” in that capacity utilization was too high and/or the unemployment rate too low. And, at least since the financial crisis, this understanding has been (like Lehman, actually) utterly bankrupt and obviously so. The chart below is a plain refutation of the notion that slack matters – although much less robust than the argument from the top economists. If slack matters, then why didn’t the greatest slack in a hundred years cause deflation in core prices? Or even get us at least close to deflation?