Do demographics and productivity explain the centuries-long decline in real interest rates?
Core argument: Global long-maturity real interest rates across 8 countries covering over 80% of advanced-economy GDP are trend stationary and show a persistent downward trend since the Renaissance, based on annual data spanning 1311–2022.
We analyze the statistical properties of global long-maturity real interest rates over the past seven centuries. The series covers over 80% of advanced-economy GDP on an annual level across 8 countries, both marketable (consolidated) debt and relevant personal loans transactions by sovereign creditors. We deflate the nominal rate in year t with a seven-year lagged inflation measure to approximate inflation expectations. Real interest rates are trend stationary and exhibit a persistent downward trend since the Renaissance. We show that demographic and productivity factors do not represent convincing drivers of real interest rates over long spans; [indeed] we can qualitatively go beyond these existing facts and find strong evidence in favor of a long-run negative prediction of aggregate population growth and aggregate real output growth for real rates. The most recent decades in which the correlation with real rates is positive appear [to be] a unique exception in a multicentury perspective.




