A new technique is demonstrated for the simultaneous estimation of potential output and the Phillips curve. In this paper, we define potential output as the non-accelerating inflation level of output (NAILO). The NAILO is not a simple trend of actual output. Instead, it is the critical level of output such that, were actual output at this level, the inflation rate would be neither accelerating nor decelerating. Our application is the case of Japan, for which we estimate both the NAILO and the Phillips curve and investigate their properties. It is shown that during the 1980s and 1990s, the Japanese output gap, as measured using the NAILO, was negative on average, reflecting the global trend of disinflation. We also point out that this NAILO-based output gap has displayed a tendency to move in line with corporate sentiment and is thus a useful indicator of business conditions. However, being subject to re-estimation due to the revision of source data and the arrival of new data, the NAILO estimate is surrounded by uncertainty. This uncertainty needs to be kept in mind in real-time analysis, and the NAILO estimate should be interpreted with care, particularly in the process of policymaking.
Keywords: Potential output; Phillips curve; Hodrick-Prescott filter
Views expressed in the paper are those of the authors and do not necessarily reflect those of the Bank of Japan or Institute for Monetary and Economic Studies.