Can central banks’ monetary policy be described by a linear (augmented) Taylor rule or by a nonlinear rule?

The original Taylor rule establishes a simple linear relation between the interest rate, inflation and the output gap. An important extension to this rule is the assumption of a forward-looking behaviour of central banks. Now they are assumed to target expected inflation and output gap instead of current values of these variables. Using a forward-looking monetary policy reaction function, this paper analyses whether central banks’ monetary policy can indeed be described by a linear Taylor rule or, instead, by a nonlinear rule. It also analyses whether that rule can be augmented with a financial conditions index containing information from some asset prices and financial variables. The results indicate that the monetary behaviour of the European Central Bank and Bank of England is best described by a nonlinear rule, but the behaviour of the Federal Reserve of the United States can be well described by a linear Taylor rule. Our evidence also suggests that only the European Central Bank is reacting to financial conditions.