This article focuses on the estimation of the hybrid New-Keynesian Phillips Curve with different kinds of price indices. This helps not only to find to what extent inflation in Russia reacts to the change in the phase of real business cycle, but also to estimate the ratio between agents with rational and adaptive expectations. Such knowledge might be crucial for monetary authorities, because the effectiveness of their policies depends on the understanding of inflation dynamics. Incorrect estimates of the share of rational economic agents can lead to errors in the conducting of monetary policy, which, in turn, may reduce the credibility of central bank amongst population and negatively affect the effectiveness of the future policy conduct.

The study uses three different measures of inflation based on the following indexes: the GDP deflator, the CPI, and the GDP deflator, net of export. The main method of estimation is the continuously updating general method of moments (CUE), which has a smaller bias on finite samples and more valid values of the Hansen J-test for the over identification compared to the standard generalized method of moments. Altogether, this makes the inference more valid.

The main conclusion is that it is the dynamics of inflation calculated on the basis of the GDP deflator, net of exports, that is best described by the Phillips curve equation, and that the output gap is significant and has a positive sign which is consistent with the theory. Mayhap this is due to the fact that the prices of imported and exported goods are not explicitly included to this measure of inflation, that is, it can be referred to as some "internal" inflation. Also, an important result is a slightly greater weight of forward looking expectations in the formation of the inflationary process.