How does overpopulation cause poverty?

Overpopulation, the situation of having large numbers of people with too few resources and too little space, is closely associated with poverty. It can result from a high population or from low amounts of resources, or from both. Only a certain number of people can be supported on a given area of land, and that number depends on how much food and other resources the land can provide. In countries where people live primarily by means of simple farming, gardening, herding, hunting, and gathering, even large areas of land can support only small numbers of people because these labor-intensive subsistence activities produce only small amounts of food.

In developed countries such as the United States, Japan, and the countries of Western Europe, overpopulation generally is not considered a major cause of poverty. These countries produce large quantities of food through mechanized farming, which depends on commercial fertilizers, large-scale irrigation, and agricultural machinery. This form of production provides enough food to support the high densities of people in metropolitan areas.

High birth rates contribute to overpopulation in many developing countries. Children are assets to many poor families because they provide labor, usually for farming. Cultural norms in traditionally rural societies commonly sanction the value of large families. Also, the governments of developing countries often provide little or no support, financial or political, for family planning, even people who wish to keep their families small have difficulty doing so, because they do not know or unable to get contraception. For all these reasons, developing countries tend to have high rates of population growth.

Most developed countries provide considerable political and financial support for family planning. People tend to limit the number of children they have because of the availability of this support, for example contraception.