Population growth rates in perfect contraceptive populations.

Abstract Eventually, world population must cease to grow. In many countries attempts are made to decrease population growth by providing family planning services to all who want to prevent pregnancies. In this paper we use the concept 'perfect contraceptive population',(1) - a population in which no unwanted births occur - to derive estimates of the maximum contribution that prevention of unwanted births might make toward attaining a zero rate of natural increase in population.