Expectations and the inertia of inflation: The case of Indonesia

It has long been recognised that the balance between backward-looking and forward-looking expectations has critical policy implications. This is because backward-looking expectations impart a substantial degree of inertia to the inflation rate whereas forward-looking expectations lead to rapid adjustment in response to shocks. In this paper we examine the policy implications for the Indonesian economy of the form taken by the price adjustment equation. We allow for both backward-looking and forward-looking effects of inflation expectations, proxying forward expectations with the realised rate and using a GMM estimator to allow for the resulting endogeneity. Using monthly data from 1980:1 to 2008:12, our estimates show that CPI inflation in Indonesia is significantly determined by backward-looking inflation expectations, forward-looking inflation expectations, the output gap, exchange rate depreciation, and money growth. However, the backward expectation attracts a significantly higher weight than the forward rate leading to the conclusion that inflation in Indonesia has considerable inertia. The implication of this is that a gradualist monetary policy is likely to be more effective as a means of smoothing fluctuations in inflation and real output.