Population density, fertility, and demographic convergence in developing countries

Whether the population tends towards a long-run stationary value depends on forces of demographic convergence. One such force is the result of fertility rates being negatively affected by population density. We test the existence of such an effect in 44 developing countries, matching georeferenced data from the Demographic and Health Surveys for half a million women with population density grids. We find a causal relationship from population density to fertility such that a rise in density from 10 to 1000 inhabitants per square kilometer corresponds to a decrease in fertility of about 0.7 children. The corresponding half-life for population dynamics is of the order of four–five generations.