by Scott Sumner
Econlib
Almost every time I see an expert interviewed on the macroeconomy, they suggest that a substantial portion of the inflation over the past 5 years has been supply side. That’s wrong; none of it has been supply side. I’d go even further; essentially none of the inflation over the past 50 years has been supply side.
To be clear, I am speaking of the total cumulative increase in prices over 5 years, or over 50 years. It is true that some of the inflation in 1979 was supply side, as well as some of the inflation during 2008, or 2022. There have been individual years where negative supply shocks pushed up prices, but just as many years where positive supply shocks pushed down prices.
Many experts implicitly seem to think there’s some sort of “ratchet effect”, where negative supply shocks push up prices, and then inflation settles back to its average rate. That’s false. When negative supply shocks are not causing inflation to rise above average, positive supply shocks cause it to fall below average.