pgl asks a good question on my previous post discussing speculation that, thanks to the Fed, the inflation risk premium built into real interest rates has fallen.
On inflation risk premiums, I'll concede they are lower now than say in 1980. But why would anyone suggest they are lower now v. say 10 years ago? Inflation has been low for almost 20 years.
I think I have an answer for that one. Because a picture is worth a thousand words (in this case anyway), here's the monthly 12-month growth rate of the CPI (in percentage terms), from 1983 through 2004:
This is impressionistic -- I arbitrarily split the sample at 1993 -- but if you did a formal, statistical break test on the trend, you'd come up with something pretty darn close. (We regularly did these tests at the Cleveland Fed until, sometime after 1995, we became convinced that the mean of the inflation rate really had shifted down.) The volatility decreased as well, as is apparent from eye-balling the picture.
So, the post 1970s period does seem to be comprised of of two distinct regimes -- the 80s and the 90s. The former was a big improvement over the 1970s, to be sure. But it seems that another step forward in monetary policy occurred in the 1990s as well.
Here's hoping it lasts.