Der Beitrag alternativer NAIRU-Kurven zur Erklärung der Inflation

The Non-Accelerating Inflation Rate of Unemployment (NAIRU) is a major concept in (monetary) economics in predicting changes in the inflation rate. As the inflation neutral unemployment rate is an unobserved and, in the long run, a changing variable, several questions arise about its adequate estimation. The following study determines four different possible NAIRU-curves for the German economy during the period of 1973Q1-2010Q2 by the use of a State-Space-Model. With the help of the Ordinary-Least-Square (OLS) and the Maximum-Likelihood (ML) method, these curves are implemented and utilized in regression models which are trimmed to satisfactorily explain inflation changes. It turns out that besides the NAIRU, several other variables like the changes in the unemployment rate or the labor productivity are necessary to forecast changes in the inflation rate accurately. Among the four regression models, the one applying the NAIRU with the lowest variance and with a high theoretic plausibility has the worst record, while the equation with a NAIRU fluctuating more than the unemployment rate explains the inflation rate best.