Functionalism: Population and the environment aﬀect each other. Normal
population growth is essential for any society, but population growth that is too
great or too little leads to various problems. Environmental problems are to be
expected in an industrial society, but severe environmental problems are
Conﬂict theory: Population growth is not a serious problem because the world
has suﬃcient food and other resources, all of which must be more equitably
distributed. The practices of multinational corporations and weak regulation of
these practices account for many environmental problems.
Demography - The study of population growth and changes in population
It encompasses several concepts: fertility and birth rates, mortality and death rates, and
Fertility - The number of live births.
Crude birth rate - The number of live births for every 1,000 people in a population in a
General fertility rate (aka the fertility rate or birth rate) - The number of live births per
1,000 women aged 15-44 (childbearing age)
Total fertility rate - The number of children an average woman is expected to have in her
Fertility rates differ around the world and are especially high in poor nations.
First, poor nations are usually agricultural ones. In agricultural societies, children are an
important economic resource, as a family will be more productive if it has more
children. This means that families will ordinarily try to have as many children as
possible. Second, infant and child mortality rates are high in these nations. Because
parents realize that one or more of their children may die before adulthood, they have
more children to make up for the anticipated deaths.
A third reason is that many parents in low-income nations prefer sons to daughters,
and, if a daughter is born, they try again for a son. Fourth, traditional gender roles are
often very strong in poor nations, and these roles include the belief that women should
be wives and mothers above all. With this ideology in place, it is not surprising that
women will have several children. Finally, contraception is uncommon in poor nations.
Without contraception, many more pregnancies and births certainly occur. For all these
reasons, then, fertility is much higher in poor nations than in rich nations. Mortality and Death Rates:
Mortality is the number of deaths. It is measured by the crude death rate.
Crude death rate - The number of deaths for every 1,000 people in a population in a
The movement of people into and out of specific regions.
Immigration rate is the number of people moving into a region for every 1,00 people in
Emigration is the number of people moving from the region for every 1,000 people
The difference between the two is the net migration rate (immigration minus
Domestic migration happens within a country's national borders, as when retired people
from the northeastern United States move to Florida or the Southwest. International
migration happens across national borders.
Population Growth and Decline:
Natural growth rate is simply the difference between the crude birth rate and the crude
Overall, the world population is growing by about 80 million people annually.
To determine how long it takes for a nation to double its population size, divide the
number 70 by its population growth rate.
Population growth begins to level off after exploding.
Views of Population Growth:
One of the first to warn about population growth was Thomas Malthus, an English
economist, who said that population increases geometrically (2, 4, 8, 16, 32, 64, 128,
256, 512, 1024…). If you expand this list of numbers, you will see that they soon become
overwhelmingly large in just a few more “generations.” Malthus said that food
production increases only arithmetically (1, 2, 3, 4, 5, 6…) and thus could not hope to
keep up with the population increase, and he predicted that mass starvation would be
the dire result. During the 1970s, population growth became a major issue in the United States and
some other nations. Zero population growth, or ZPG, was a slogan often heard. There
was much concern over the rapidly growing population in the United States and,
especially, around the world, and there was fear that our “small planet” could not
support massive increases in the number of people.
The Debate over Overpopulation:
Many experts continue to be concerned about overpopulation, as they feel it is directly
responsible for the hunger and malnutrition that plague hundreds of millions of people
in poor nations.
The official added that enough grain (cereal and soy) exists to easily feed the world, but
that one-third of cereal and 90 percent of soy feed livestock instead. Moving away from
a meat-laden Western diet would thus make much more grain available for the world’s
Sociologists Stephen J. Scanlan and colleagues add that food scarcity results from
inequalities in food distribution rather than from overpopulation: “[Food] scarcity is
largely a myth. On a per capita basis, food is more plentiful today than any other time in
International organizations such as the World Bank and several United Nations
agencies have long believed that hunger is due to food scarcity, and this belief underlies
the typical approaches to reducing world hunger that focus on increasing food supplies
with new technologies and developing more efficient methods of delivering food. But if
food scarcity is not a problem, then other approaches are necessary.
Scanlan et al. point out that poor nations lack the funds to import the abundant food
that does exist. These nations’ poverty, then, is one inequality that leads to world
hunger, but gender and ethnic inequalities are also responsible. Nations with higher
rates of gender inequality and ethnic inequality have higher rates of hunger. In view of
this fact, the authors emphasize that improvements in gender and ethnic equality are
necessary to reduce global hunger.
Demographic Transition Theory:
This theory links population growth to the level of technological development across
three stages of social evolution and suggests that this growth slows considerably as
nations become more industrialized.
In the first stage, coinciding with preindustrial societies, the birth rate and death rate
are both high. The birth rate is high because of the lack of contraception and the several
other reasons cited earlier for high fertility rates, and the death rate is high because of disease, poor nutrition, lack of modern medicine, and other problems. These two high
rates cancel each other out, and little population growth occurs.
In the second stage, coinciding with the development of industrial societies, the birth
rate remains fairly high, owing to the lack of contraception and a continuing belief in the
value of large families, but the death rate drops because of several factors, including
increased food production, better sanitation, and improved medicine. Because the birth
rate remains high but the death rate drops, population growth takes off dramatically.
In the third stage, the death rate remains low, but the birth rate finally drops as families
begin to realize that large numbers of children in an industrial economy are more of a
burden than an asset. Another reason for the drop is the availability of effective
contraception. As a result, population growth slows, and, as we saw earlier, it has
become quite low or even gone into a decline in several industrial nations.
Population Decline and Pronatalism:
For a country to maintain its population, the average woman needs to have 2.1 children,
the replacement level for population stability. But several industrial nations, not
including the United States, are below this level. Increased birth control is one reason
for their lower fertility rates but so are decisions by women to stay in school longer, to
go to work right after their schooling ends, and to postpone having their first child.
Because people in many industrial nations are living longer while the birth rate drops,
these nations are increasingly having a greater proportion of older people and a smaller
proportion of younger people.
As this trend continues, it will become increasingly difficult to take care of the health
and income needs of so many older persons, and there may be too few younger people to
fill the many jobs and provide the many services that an industrial society demands. The
smaller labor force may also mean that governments will have fewer income tax dollars
to provide these services.
Pronatalist - Referring to policies that encourage women to have children
In particular, they provide generous child-care subsidies, tax incentives, and flexible
work schedules designed to make it easier to bear and raise children, and some even
provide couples outright cash payments when they have an additional child.
Two Other Problems Related to Population Growth:
Countries with large numbers of people drive many motor vehicles that pollute the air,
and these countries engage in many other practices of the industrial era that pollute the
air, water, and ground. Further, as populations have expanded over the centuries, they have cut down many
trees and deforested many regions across the globe. This deforestation ruins animal
habitats and helps to contribute to global warming because trees help remove carbon
dioxide from the atmosphere and release oxygen into the atmosphere.
As populations grow, they need more and more food, water, and other resources. When
these resources have become too scarce over the centuries, many societies have decided
to take resources from other societies.
The history of the United States is filled with prejudice and hostility of this type. Starting
with the Pilgrims, this nation was settled by immigrants who came to these shores
seeking political and religious freedom and economic opportunity. Despite these origins,
when great waves of immigrants came to the United States beginning in the nineteenth
century, they were hardly greeted with open arms.
Almost 40 percent of Latinos and two-thirds of Asians in the United States are foreign-
In another fact that may surprise immigration opponents, many studies also find that
immigrants, both legal and illegal, have lower crime rates than nonimmigrants. These
low rates are thought to stem from immigrants’ stable families, strong churches, and
high numbers of small businesses that make for stable neighborhoods. Ironically, as
immigrants stay longer in the United States, the crime rates of their children, and then
those of their children’s children, become higher. As immigrant families stay longer in
the United States, then, their crime rates tend to rise, in part because they become
Efforts to Limit Immigration:
In a 2011 CNN poll, one-third of the public said it is “somewhat” or “very”
unsympathetic toward illegal immigrants and their families. In the same poll, more than
half the public favored building a seven-hundred-mile fence along the border with
Many critics of immigration hope these and other laws (having to carry documentation
at all times) and practices will make life so difficult for unauthorized immigrants that
they engage in self-deportation by returning to Mexico or their other native countries.
There is little evidence that self-deportation actually occurs. A major reason for this fact
is that two-thirds of unauthorized adult immigrants have been in the United States for
at least ten years, a