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 religions encourage
large families.
