Patience breeds interest : the rise of societal patience and the fall of the risk-free interest rate

Abstract

The risk-free rate of return has been declining in real terms over millennia. We isolate the role of time preference – or patience – in explaining this decline. Three facts support our approach: experimental evidence finds significant heterogeneity in patience; individual preference characteristics are highly intergenerationally persistent; and, longitudinal data shows that patience is positively related with fertility decisions. Together these suggest we should expect average societal levels of patience to increase over time as the composition of the population shifts towards ever more patient dynasties. We test this mechanism in a Barro-Becker model of fertility with heterogeneous dynasties. We use the present day distribution of patience to calibrate the model. We are able match – both quantitatively and qualitatively – the decline in the risk-free return over the last eight centuries.