Paul Samuelson made a series of important contributions to population theory for humans and other species, evolutionary … theory, and the theory of age structured life cycles in economic equilibrium and growth. The work is highly abstract but much … of it was intended to illuminate issues of compelling policy importance, such as declining fertility and population aging …

We set up an overlapping generations model with endogenous fertility to study pensions policies in an ageing economy … have negative effects on the fertility rate, thus exacerbating population ageing. …