ABSTRACT
Population growth is both an asset and a liability for development. It is an asset in that a growing population is a source of youthful labor, social-security contributions, and expanding markets. At the household level, children are sources of income and protection for their parents. Poor people typically prefer to have larger numbers of children as both a choice and a necessity. But they are also a liability. From a simple arithmetical standpoint, population growth subtracts from GDP growth in determining growth in per capita income. It also tends to be a source of declining land per capita, food insecurity, environmental degradation, congestion externalities, and urban blight, as well as a drain on public goods and services. There are both positive and normative questions associated with population growth. Positive questions include: what are the determinants of fertility behavior? Why do countries go through a demographic transition with a phase of exploding population growth? Why is there a decline in population growth as per capita income rises? How do countries benefi t from a one-time demographic dividend as fertility declines while the share of elderly people in the population is still relatively low? Normative questions include: how can we reduce population growth if it is deemed excessive? If contraception is the main instrument to reduce fertility, when is it more important to focus on the supply side and when on the demand side of contraception?
