 Demographically realistic overlapping generations models, in which agents can live for up to, say, 100 years, are very complicated mathematical structures.Agents who are young would, if they were rational and precognitive, consider all future interest rates and wage rates in deciding how much to save and work in the current as well as in their remaining future years.This path of interest rates and wage rates will, in turn, depend on the course of the economy's relative supplies of capital and labor, since these relative supplies determine whether capital or labor is relatively scarce in any given future year and, therefore, what these factors of production will get paid in the competitive market.