The observational equivalence of the Taylor Rule and Taylor-type rules

In a variety of recent papers, researchers have found that interest rate behaviour approximately follows a Taylor rule. From this they have concluded that the central bank is following a Taylor rule as its monetary policy reaction function. We show that such interest rate behaviour results when the central bank may be following quite different monetary policy rules from the one proposed by Taylor. In other words an interest rate relation with output and inflation does not identify a central bank reaction function.