'Some Big Changes in Macroeconomic Thinking from Lawrence Summers'

Adam Posen:

Some Big Changes in Macroeconomic Thinking from Lawrence Summers: ...At a truly fascinating and intense conference on the global productivity slowdown we hosted earlier this week, Lawrence Summers put forward some newly and forcefully formulated challenges to the macroeconomic status quo in his keynote speech. [pdf] ...

The first point Summers raised ... pointed out that a major global trend over the last few decades has been the substantial disemployment—or withdrawal from the workforce—of relatively unskilled workers. ... In other words, it is a real puzzle to observe simultaneously multi-year trends of rising non-employment of low-skilled workers and declining measured productivity growth. ...

Another related major challenge to standard macroeconomics Summers put forward ... came in response to a question about whether he exaggerated the displacement of workers by technology. ... Summers bravely noted that if we suppose the “simple” non-economists who thought technology could destroy jobs without creating replacements in fact were right after all, then the world in some aspects would look a lot like it actually does today...

The third challenge ... Summers raised is perhaps the most profound... In a working paper the Institute just released, Olivier Blanchard, Eugenio Cerutti, and Summers examine essentially all of the recessions in the OECD economies since the 1960s, and find strong evidence that in most cases the level of GDP is lower five to ten years afterward than any prerecession forecast or trend would have predicted. In other words, to quote Summers’ speech..., “the classic model of cyclical fluctuations, that assume that they take place around the given trend is not the right model to begin the study of the business cycle. And [therefore]…the preoccupation of macroeconomics should be on lower frequency fluctuations that have consequences over long periods of time [that is, recessions and their aftermath].”

I have a lot of sympathy for this view. ... The very language we use to speak of business cycles, of trend growth rates, of recoveries of to those perhaps non-stationary trends, and so on—which reflects the underlying mental framework of most macroeconomists—would have to be rethought.

Productivity-based growth requires disruption in economic thinking just as it does in the real world.

The  full text explains these points in more detail (I left out one point on the measurement of productivity).