The time-frequency analysis of conventional and unconventional monetary policy: Evidence from Japan

The effects of monetary policy on the aggregate economy is an important issue that has been addressed mainly in the time domain, and relatively little is known about how monetary policy affects the macroeconomy in the time-frequency space. With a continuous wavelet multiple coherency and partial coherency approach, this paper contributes to the literature by characterizing the macroeconomic effects of monetary policy across frequencies and over time using a monthly dataset from Japan, which is in the vanguard in the practice of unconventional monetary policy. The empirical results show that: First, interest rate changes could be largely captured by inflation fluctuations across frequencies before 1999 but only at low frequencies after 1999. Second, movements of M1 could well reflect the variations of industrial production at the scale of 2–4 years before 1999, but this relationship was reversed at the same scale after 1999. Third, changes in M2 could roughly mirror the fluctuations of inflation at the scale of 3–4 years between 1966 and 1969, and this relationship was reversed at the scale of 1–3 years between 2003 and 2007. This study indicates that in Japan conventional and unconventional monetary policy generate heterogeneous effects on the aggregate economy and the level of heterogeneity partially depends on the chosen instrument.