Real-Time Estimation of the Output Gap in Japan and its Usefulness for Inflation Forecasting and Policymaking

This paper examines the methods used by the Bank of Japan for the estimation of the output gap. Attention is paid to the real-time estimation problem. After reviewing the evolution of output gap estimation at the Bank, I discuss advantages and disadvantages of the various output gap measures. First, I examine the usefulness of the output gap for inflation forecasting and show that the real-time output gap sometimes includes much noise. Second, I investigate the implications of the real-time estimation problem for the policy evaluation. Third, I exploit TANKAN to enhance the usefulness of the real-time output gap.