Garcia Schmidt and Woodford on neo-Fisherian economcs

Mariana Garcia Schmidt and Mike Woodford are lighting up the internet with a presentation on neo-Fisherian economics -- the proposition that, when we are satiated in money as at the zero bound or with interest on reserves, raising interest rates raises inflation. Noah Smith, Marginal Revolution, Brad DeLong, and indirectly at Mark Thoma's econbrowser.

This is a particularly important voice, as it seemed to me that standard New-Keynesian models produce the new-Fisherian result. i = r + Epi is a steady state in all models. In old-Keynesian models, it was an unstable steady state, so an interest rate peg leads to explosive inflation or deflation. But in new-Keynesian models, an interest rate peg is the stable/indeterminate case. There are too many equilibria, but if you raise interest rates, inflation always ends up rising to meet the higher interest rate.

What I can glean from the slides is that Garcia Schmidt and Woodford agree: Yes, this is what happens in rational expectations or perfect foresight versions of the new-Keynesian model. But if you add learning mechanisms, it goes away.

My first reaction is relief -- if Woodford says it is a prediction of the standard perfect foresight / rational expectations version, that means I didn't screw up somewhere. And if one has to resort to learning and non-rational expectations to get rid of a result, the battle is half won.

But that's only preliminary relief. Schmidt and Woodford promise a paper soon, which will undoubtedly be well crafted and challenging.

For more on the issue, here is a a previous blog post. Section 3.1 ff of "Monetary policy with interest on reserves" has a full new Keynesian model with the Fisherian result. And a wry prediction: the Fed will raise rates to head off inflation, that will cause the inflation, then the Fed will congratulate itself on having headed off the inflation.  I also suspect that models with restricted liquidity (no interest on reserves) do give a temporary decline in inflation, but without that liquidity we now will get full Fisherian results. But that's just a conjecture so far.  My last foray into learning in new-Keynesian models, which didn't end well.

Why post now? Garcia Schmidt and Woodford clearly will have a thoughtful and sophisticated paper, on what I think is a deep and important point. I hope to encourage others to read and help to digest the paper.