General population increase in the world was negligible until the Industrial Revolution. From the time of the Roman Empire to the colonization of America, the world population grew from about a quarter billion to a half billion persons. By the mid-19th cent., however, it had grown to about one billion, and by 1930 it had risen to 2 billion; the United Nations estimates the world population will peak at 10 billion in 2200. In world terms, the population is growing at about 1.2% annually (compared with 0.1% in ancient times and a rate of 1.75% as recently as the 1990s) in population. Although a 1.2% growth rate may appear small, it annually adds some 77 million persons to the world's population, with nearly all of this growth taking place in less developed nations.
During the Industrial Revolution, advancements in sanitation, technology, and the means of food distribution made possible a drop in the death rate so significant that between 1650 and 1900 the population of Europe almost quadrupled (from about 100 million to about 400 million) in spite of considerable emigration. As the rate of population growth increased, so did concern that the earth might not be able to sustain future populations. The phenomenal increase in numbers led Thomas Robert Malthus to predict that the population would eventually outstrip the food supply. Karl Marx emphatically rejected this view and argued that the problem was not one of overpopulation but of unequal distribution of goods, a problem that even a declining population would not solve.Modern Population Growth
In the late 20th cent., a major population difference arose in the comparative growth rates of the developed (0.6%) and developing (2.1%) nations. Africa's annual growth rate is about 3%, compared to 1.7% for Asia, 0.7% in Latin America, and 0.3% in Europe. If current rates hold steady, many developing countries will double their populations in 25 years or less, compared to 50 years or more for industrialized nations. Great Britain, for example, has a present doubling rate of 140 years, while Costa Rica has one of 19 years.
Great Britain has accomplished what is known as demographic transition, i.e., it has moved from a condition of high birthrate and high death rate (before the Industrial Revolution), to one of high birthrate and low death rate (during industrialization), and finally to one of low birthrate and low death rate (as a postindustrial society). Most of the countries in the Third World are in a condition of high birthrate and declining death rate, contributing to what is known as the population explosion.
A declining birthrate depends to a large extent on the availability and use of birth control and on high living standards that make unnecessary the production of additional children to provide necessary and inexpensive labor. Family planning is national policy in many industrial countries, such as Japan and most of Europe. As a result, in most cases the birthrate has declined. Many developing countries have followed the lead of India (which has since 1952 conducted an extensive, but not totally successful, birth control program) in trying to promote family planning as national policy. These countries include China, Kenya, Pakistan, Taiwan, Turkey, Egypt, and Chile.
In the United States, aspects of the population question, such as birth control and abortion, are among the most bitterly debated subjects. The United States has opposed at times the use of foreign aid appropriations for family planning overseas; domestic family planning is mainly run by private groups such as Planned Parenthood.
A number of nongovernmental organizations concerned with population growth have also appeared. Zero Population Growth, an educational group founded in 1970, aims to stop population growth, first in the United States and then in other countries. On the international level, besides the International Planned Parenthood Federation, the United Nations Economic and Social Council provides birth control aid to underdeveloped nations.
See D. Glass and D. Eversley, Population in History (1965); W. D. Borrie, The Growth and Control of World Population (1970); N. W. Chamberlain, Beyond Malthus (1970); D. Fraser, The People Problem (1971); P. Hauser, Population and the Urban Future (1982); K. Davis, Resources, Environment and Population (1991).
Statistical study of human populations, especially with reference to size and density, distribution, and vital statistics. Contemporary demographic concerns include the global birth rates, the interplay between population and economic development, the effects of birth control, urban congestion, illegal immigration, and labour force statistics. The basis for most demographic research lies in population censuses and the registration of vital statistics.
Learn more about demography with a free trial on Britannica.com.
Enumeration of people, houses, firms, or other important items in a country or region at a particular time. The first U.S. population census was taken in 1790 to establish a basis for representation in Congress. Censuses were taken in England, France, and Canada in 1801, 1836, and 1871, respectively. China was the last major country to report a census, in 1953. Census information is obtained by using a fixed questionnaire covering such topics as place of residence, sex, age, marital status, occupation, citizenship, language, ethnicity, religious affiliation, and education. From the responses demographers derive data on population distribution, household and family composition, internal migration, labor-force participation, and other topics. Seealso demography.
Learn more about census with a free trial on Britannica.com.
In biology a population is the collection of inter-breeding organisms of a particular species; in sociology, a collection of human beings. A population shares a particular characteristic of interest, most often that of living in a given geographic area. In taxonomy population is a low-level taxonomic rank.
Human populations can be defined by any characteristics such as mortality, migration, family (marriage and divorce), public health, work and the labor force, and family planning. Various aspects of human behavior in populations are also studied in sociology, economics, and geography.
Study of populations is almost always governed by the laws of probability, and the conclusions of the studies may thus not always be applicable to some individuals. This odd factor may be reduced by statistical means, but such a generalization may be too vague to imply anything. Demography is used extensively in marketing, which relates to economic units, such as retailers, to potential customers. For example, a coffee shop that wants to sell to a younger audience looks at the demographics of an area to be able to appeal to this younger audience.
In 2007 the United Nations Population Division projected that the world's population will likely surpass 10 billion in 2055. The last 50 years have seen a rapid increase in population due to medical advances and substantial increase in agricultural productivity, particularly in the period 1960 to 1995 made by the Green Revolution.
An important example of mandated population control is People's Republic of China's one-child policy, in which having more than one child is made extremely unattractive. This has led to allegations that practices like forced abortions, forced sterilization, and infanticide are used as a result of the policy. The country's sex ratio at birth of 112 boys to 100 girls may be evidence that the latter is often sex-selective. However, other countries without a one-child policy also have similar sex ratios but for different reasons.
It is helpful to distinguish between fertility control as individual decision-making and population control as a governmental or state-level policy of regulating population growth. Fertility control may occur when individuals or couples or families take steps to decrease or to regulate the timing of their own child-bearing. In Ansley Coale's oft-cited formulation, three preconditions for a sustained decline in fertility are: (1) acceptance of calculated choice (as opposed to fate or chance or divine will) as a valid element in fertility, (2) perceived advantages from reduced fertility, and (3) knowledge and mastery of effective techniques of control. In contrast to a society with natural fertility, a society that desires to limit fertility and has the means to do so may use those means to delay childbearing, space childbearing, or stop childbearing. Delaying sexual intercourse (or marriage), or the adoption of natural or artificial means of contraception are most often an individual or family decision, not a matter of a state policy or societal-wide sanctions. On the other hand, individuals who assume some sense of control over their own fertility can also accelerate the frequency or success of child-bearing through planning.
At the societal level, declining fertility is almost an inevitable result of growing secular education of women . However, the exercise of moderate to high levels of fertility control does not necessarily imply low fertility rates. Even among societies that exercise substantial fertility control, societies with an equal ability to exercise fertility control (to determine how many children to have and when to bear them) may display widely different levels of fertility (numbers of children borne) associated with individual and cultural preferences for the number of children or size of families.
In contrast to fertility control, which is mainly an individual-level decision, governments may attempt to exercise population control by increasing access to means of contraception or by other population policies and programs. The idea of "population control" as a governmental or societal-level regulation of population growth does not require "fertility control" in the sense that it has been defined above, since a state can affect the growth of a society's population even if that society practices little fertility control. It's also important to embrace policies favoring population increase as an aspect of population control, and not to assume that states want to control population only by limiting its growth. To stimulate population growth, governments may support not only immigration but also pronatalist policies such as tax benefits, financial awards, paid work leaves, and childcare to encourage the bearing of additional children. Such policies have been pursued in recent years in France and Sweden, for example. With the same goal of increasing population growth, on occasion governments have sought to limit the use of abortion or modern means of birth control. An example was Romania's 1966 ban on access to contraception and abortion on demand.
In ecology, population control is on occasions considered to be done solely by predators, diseases, parasites, and environmental factors. At many times human effects on animal and plant populations are also considered. See also Migrations of animals may be seen as a natural way of population control, for the food on land is more abundant on some seasons. The area of the migrations' start is left to reproduce the food supply for large mass of animals next time around. See also immigration.