Did lower interest rates reduce Japan's household savings rate since the 1990s? Evidence based on the maturation of postal savings certificates

Japan's traditionally high household saving rate has declined substantially since the early 1990s. While this decline is often explained as a result of the rapid increase in the population share of the elderly who are dissaving, we argue that the cause is a decline in interest income triggered by falling interest rates. To examine our hypothesis, we focus on the effect of the maturation of relatively high-yielding postal savings certificates. Estimating a savings function, we find that the reduction in interest income caused by the maturation of the postal saving certificates reduced household saving rates by more than 3 percentage points.