The Taylor principles study looked at different periods in monetary policy history and found that the Federal Reserve sometimes didn't follow the Taylor rule, a guideline for setting interest rates based on inflation and economic output. During the Great Inflation, the Fed didn't raise rates enough, and during the Volcker disinflation, it didn't respond enough to economic output. From 2000 to 2007, the Fed didn't follow any version of the Taylor rule, but from 2007 to 2015, it either ignored inflation or focused heavily on economic output when setting interest rates.