The empirical validity of the New Keynesian Phillips curve using survey forecasts of inflation

This paper investigates the performance of the New Keynesian Phillips curve when survey forecasts of inflation are used to proxy for inflation expectations. Previous authors such as Brissimis and Magginas (2008) have applied survey measures of inflation expectations to the NKPC, and have concluded that these estimates are superior to those estimated using actual data on future inflation. However this approach employs the use of the labor income share as the proxy for real marginal cost, something which is highly problematic once we consider the countercyclicality of this variable. This paper develops and tests a procyclical marginal cost variable alongside various survey measures of inflation forecasts in the NKPC, while recognizing the problem of weak instruments that occurs when estimating the model using conventional GMM. We find that the NKPC produces a counter-intuitive negative and significant coefficient on procyclical marginal cost when surveys of inflation forecasts are used, which casts serious doubt on the empirical viability of the NKPC model, even when estimated with survey inflation forecasts.

► Many in the literature estimate the NKPC using survey forecasts of inflation. ► We estimate the NKPC with a new proxy for marginal cost, given adjustment costs. ► Using procyclical marginal cost yields a counter-intuitive negative coefficient. ► Therefore positive NKPC findings rely on the countercyclicality of marginal cost. ► Thus using survey measures of inflation forecasts in the NKPC is a secondary issue.