Assuming that a decline in labor force lowers the economic growth rate and that the extension of longevity results in an increase in savings, this study estimates that about 270 basis points can be attributed to demographic changes out of the 640 basis points decline in real interest rates over the past 50 years in Japan.
Nao Sudo and Yasutaka Takizuka, "Population Aging and the Real Interest Rate in the Last and Next 50 Years: A Tale Told by an Overlapping Generations Model," Bank of Japan Working Paper Series, no.18-E-1, January 2018, https://www.boj.or.jp/en/research/wps_rev /wps_2018/data/wp18e01.pdf.