ABSTRACT
This is the first of the special topics chapters. It begins with a brief overview of the world population situation, including presentation of long-term trends and the current global situation with regard to population levels. It then distinguishes between the situation in low-income countries – where rapid population growth is endemic – and high-income countries, where population growth is slow, stagnant, or, in many cases, declining. These two situations present different challenges for policy. The discussion then turns to a theoretical way to think about population decisions made by individual families, the well-known Becker model of fertility. The Becker model treats individual decisions on childbearing as governed by individual utility-maximization subject to income constraints. This model provides a coherent way to think about factors that affect fertility decisions. We then broaden the focus of the discussion by presenting a way to think about population trends at a more macro-level, with the famous demographic transition model. This model interprets population growth as subject to a regular empirical pattern as economies develop over time. The discussion then interprets this pattern in terms of the so-called Malthusian trap, in which the world was caught – at low levels of per capita income – for millennia until around 1800. Escape from the Malthusian trap was enabled by advances on two fronts: increases in food production and reductions in population growth. The chapter concludes with a discussion of population policies to address both high-growth and low-growth/shrinking situations.
