"Actual Federal Reserve Policy Behavior and Interest Rate Rules," FRBNY Economic Policy Review, 2001.Paper: pdf file
Several studies have attempted tomodel how the Federal Reserve makes policy choices affecting interest rates. These studies have yielded "rules" relating the interest rate that the Fed is assumed to control to a set of variables thought to affect Fed policy behavior.
Many of these studies conclude that interest rate rules do not have stable coefficient estimates over time---a finding that suggests structural change in the Fed's policy behavior.
A specification of an interest rate rule, estimated over the 1954:1-1979:3 and the 1982:4-1999:3 periods, does pass a stability test.
Nevertheless, the results show a large economic difference in the coefficient on inflation between the first and second periods, and the relatively restrained behavior of inflation in recent years makes it hard to determine whether there has been a structural break.