Population Theory Discussions of the main principles of demography and population theory not applied to actual data, including such concepts as Malthusianism, the demographic transition, overpopulation, optimum population, and stable and stationary population models as distinct from methodological studies and models using data, which are classified under N. Methods of Research and Analysis Including Models . Rodolfo A. Completing the demographic transition. Population Council Policy Research Division Working Paper, No. 125, 1999. Despite ongoing declines in fertility in many countries, the population of the world is experiencing a period of rapid expansion, and its size is expected to exceed 10 billion by the end of the demographic transition. A set of simple analytic expressions is proposed for estimating these factors from standard demographic indicators.
Population momentum is shown to be the main cause of future growth in most countries and regions.
This paper develops a unified model of growth, population, and technological progress that is consistent with long-term historical evidence. The economy endogenously evolves through three phases. The economy endogenously undergoes a demographic transition in which the traditionally positive relationship between income per capita and population growth is reversed. In the Modern Growth regime, population growth is moderate or even negative, and income per capita rises rapidly. Second, technological progress creates a state of disequilibrium, which raises the return to human capital and induces patients to substitute child quality for quantity.