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...

We develop a novel method for assessing the effect of constraints imposed by spatially-fixed natural resources on aggregate economic output. We apply it to estimate and compare the projected effects of climate change and population growth over the course of the 21st century, by country and...

This paper develops a unified growth model that captures the historical evolution of population, technology, and output. It encompasses the endogenous transition between three regimes that have characterized economic development. The economy evolves from a Malthusian regime, where technological...