Demography is the study of human populations, their characteristics, and changes.
Demographic transition is the hypothesis that economies proceed through a series of stages, resulting in stable populations and high economic development. The model is based on the historical, social, and economic development of Europe and North America.
A baby boom is a significant increase in birthrate over a specific period of time.
The age distribution of a population is the comparative percentages of different age groups within a population.
Differences in North America include: higher gross national product, higher individual income, lower infant mortality rate, higher age expectancy, lower birth rate, greater availability of food, higher consumption of energy, greater access to education, greater availability of jobs, and greater waste.
People who live in overpopulated countries use plants as their main source of food because they cannot afford the 90-percent energy loss that occurs when plants are fed to animals. The same amount of grain can support ten times more people at the herbivore level than at the carnivore level.
Factors influencing life in the future are energy availability, food availability, size of the world and national populations, and availability of resources.
If the world population were to double in the next fifty years, we would expect to see an increase in total energy consumption, travel and mobility restricted, recreational activities change, less food in third-world nations, a decrease in the standard of living, and a redistribution of wealth.
Africa, Asia, and South America have the highest population growth rates and the lowest standard of living.
The U.S. population growth rate would stabilize if each woman had less than 2.1 children. However, even at a fertility rate of one child per woman, the growth rate may still increase due to immigration.
Women in poor countries are usually poorly educated, do not have disposable income, and depend on their husband's income. They are more likely to have children they do not want because they cannot afford or understand birth control and because they view children as workers and caregivers.
Children are valued as workers and provide an income. Children provide for parents in their old age, and some cultures and eligions encourage large families.
