Stage 3 suggests that technology holds the key to population control. Instead of the out‐of‐control population explosions that Malthus predicted, demographic transition theory claims that technology will ultimately control population growth and ensure enough food for all.
Population control: The importance of family planning
Historically, many groups and societies have discouraged contraception (the prevention of conception, or birth control) to assure survival of its members and humanity as a whole. Certain religious groups strongly disapprove of sexual activity that does not culminate in coitus and the possibility of conception. Other groups place little importance on the matter of contraception. The Yanomamo of South America, for instance, harbor little or no concept of contraception. Instead, they parent as many children as possible, and then kill off those they view as the undesirable, such as some females and deformed infants.
Modern medicine has spread throughout different parts of the world, and people of all ages now live longer, causing the world's population to explode in growth. In fact, at five billion today, the world's population doubles, on average, every 35 years, with most of this growth occurring in developing countries. Given this population crisis, certain governments, like that of China, regulate the number of births allowed per household.
Besides the issue of controlling overpopulation, other benefits to practicing contraception exist. For example, a young couple may want to postpone having children until their finances improve. Or an unmarried, sexually active teenager may wish to finish her education or get married before starting a family, thereby reducing her chances of eventually relying on the government for financial support.
Family planning also plays an important role in protecting the physical health of both mother and child. The older or younger a woman is, and the closer together she bears children (that is, more frequently than every two years), the greater the risk of pregnancy and birth complications, early infant mortality, and maternal death. For example, women over age 40 or under age 19 have an increased risk of bearing a child of low birth weight, and thus a variety of birth defects and even outright death. Estimates say that approximately one million teenage women in the United States become pregnant each year.