Birth and death rates

Birth and death rates are important measurements of population changes. They provide a way to... More >>

Birth control

Birth control is a term that includes all methods used to regulate or prevent the birth of... More >>

Census

Census is a survey conducted by a national government to gather information about the society... More >>

Collective behavior

Collective behavior is a term in sociology that refers to how people act in crowds and other... More >>

Condom

Condom is a thin rubber or plastic sheath that may be worn over a man's penis during sexual... More >>

Demography

Demography, dih MOG ruh fee, is the study of human populations. Demographers (population experts)... More >>

Ehrlich, Paul Ralph

Ehrlich, AYR lihk, Paul Ralph (1932-...), an American biologist, is a leader of the international... More >>

Life expectancy

Life expectancy is a statistical measure of the average number of years that a group of people of... More >>

Migration

Migration, in biology, is the movement of animals to a place that offers better living... More >>

Nomad

Nomad is a person who moves from one place to another as a way of making a living. The word nomad... More >>

Planned Parenthood Federation of America

Planned Parenthood Federation of America is an organization concerned mainly with voluntary... More >>

Population

Population of a country or other area is the total number of people who live in it. Populations... More >>

Sex ratio

Sex ratio is the proportion of males to females in a population. Studies of birth records for... More >>

United States census

United States census is an extensive nationwide information-gathering project conducted by the... More >>

United States census of 2000

United States census of 2000 was an extensive nationwide information-gathering project conducted... More >>