Sociology of Demography and Ecology

Demography is the scientific study of human population and its processes, such as fertility, mortality, and migration, and how these factors change over time and affect population size, growth, structure and composition, and the natural environment. The field of demography typically has been organized in terms of two strands of scholarship: formal and social demography.

Ecology generally refers to the scientific study of an organism or community of organisms and their relationship to each other as well as to the environment. The ecological framework is used in biological sciences, social sciences, botany, zoological sciences, and other research areas and is applied to myriad subareas including human ecology, cultural ecology, organizational ecology, plant ecology, population ecology, spatial ecology, and more. Early writings on ecology were influenced by the works of Malthus and Darwin. This can be seen in ecology's use of natural selection and the presence of other competing species in the race for survival.

Age, Period, and Cohort Effects

Age, period, and cohort are variables often used in social research that are so closely interrelated that the effects of one cannot be studied without consideration of the effects of the others. Each variable is a perfect linear function of the other two, which means that when any two are statistically held constant, the third […]

Demography of Aging

The demography of aging began to emerge as a distinct subfield within demography during the second half of the twentieth century, when low fertility and mortality rates were creating dramatic shifts in the age structure of developed countries. Early in this field’s development, demography of aging researchers were focused on defining old age and aging, […]


Although still a modest subfield within demography, biodemography is arguably the fastest growing part of demography and one of the most innovative and stimulating. The two main branches today involve: (1) biological-demographic research directly related to human health, with emphasis on health surveys, a field of research that might be called biomedical demography (or ”epidemography […]

Kingsley Davis

Kingsley Davis, a grand-nephew of Confederate President Jefferson Davis, earned a Ph.D. from Harvard University studying with Talcott Parsons, Pitrim Sorokin, W. Lloyd Warner, and Carle Zimmerman. As one of the most influential and eminent sociologists of the twentieth century, he made major contributions to sociology, anthropology, and demography. A pioneer of sociological theory as […]

Demographic Data: Censuses, Registers, Surveys

Population censuses, registers, and surveys are the primary sources of demographic data, including information about the size, composition, and characteristics of a population or population subgroups. CENSUSES A census is an enumeration of all households in a well-defined territory at a given point in time. In the USA, data from the decennial census are used […]

Demographic Techniques: Population Pyramids and Age/Sex Structure

Age and sex are among the most fundamental demographic characteristics of individuals. Viewed in the aggregate, age/sex composition forms the basic structure of human populations. It tells us the relative numbers of young and old as well as the balance of men and women at different ages. By characterizing the ”raw materials” of human populations, […]

Demographic Techniques: Time Use

Time allocation is a major indicator of social differentiation and stratification. People with high levels of human capital may be better able to trade paid work time for leisure time and purchase time-saving goods and services than people with lower levels of human capital. Moreover, time use decisions have important implications for people’s health, financial […]

Demographic Transition

The demographic transition theory began as a description of the demographic changes that had taken place over time in the advanced nations: The transition from high birth and death rates to low birth and death rates, with an interstitial spurt in growth rates leading to a larger population at the end of the transition than […]


WHAT IS DEMOGRAPHY? Demography is the scientific study of human population and its processes, such as fertility, mortality, and migration, and how these factors change over time and affect population size, growth, structure and composition, and the natural environment. The field of demography typically has been organized in terms of two strands of scholarship: formal […]

Ecological Problems

Sociology devoted to local and global ecological problems (like air pollution in cities, the greenhouse effect, or overfishing of the oceans) is active in at least three areas of research: theories of the emergence of ecological problems, environmental attitudes and behavior of the general public, and environmental behavior of corporate actors (business firms, environmental movement […]

Environmental Problems

Humans have faced poor environmental conditions throughout history, but what we think of as ”environmental problems” became more common and apparent with urbanization. In the USA urban air and water pollution attracted growing attention throughout the last century, and by the 1960s became recognized as significant problems. Celebration of the first ”Earth Day” on April […]

Environmental Sociology

Environmental sociology emerged in the 1970s, largely in response to widespread societal awareness of environmental problems and mobilization of support for environmental protection symbolized by celebration of the first ”Earth Day” in 1970. Early sociological research on environmental topics involved analyses of public opinion toward environmental issues; environmental activism at both the individual and organizational […]

Fertility and Public Policy

Fertility levels vary widely among contemporary populations, from a high of 7.2 births per woman in Niger to a low of 0.9 in Macao (United Nations 2007). These levels are largely the result of decisions made by individual couples who are trying to maximize their families’ welfare. The fertility that results from this individual decision-making […]

Fertility: Transitions and Measures

Childbearing, or the fertility of human populations, has changed profoundly in the last several centuries. Four aspects are basic for measuring and studying human fertility: age, parity (number of children ever born), length of birth interval, and population reproductivity. Additionally, there are cross-cutting issues of time perspective and of fertility dimensions. The variety of fertility […]

HIV/AIDS and Population

The connections between human immunodeficiency virus (HIV) and population features are vast. While HIV has its largest impacts on population size and structure by increasing mortality among young adults, it also affects and interacts with the other key components of population make-up and change, namely, sexual behavior and fertility, and migration. Impacts on these key […]

Immigration Policy

Immigration policy specifies the laws and practices that allow persons to move permanently to other countries and petition for citizenship or to enter and stay for delimited lengths of time without the right to apply for citizenship. In developed countries, such policies include not only voluntary work and occupation-based and family-based migration but also the […]


Infertility is the physical inability to conceive a child or to successfully carry a child to term. Most medical professionals consider a couple to be infertile if they have failed to conceive after twelve months of unprotected intercourse. Either partner or both may have the reproductive impairment. Between 8 and 12 percent of couples -or […]

Thomas Robert Malthus

Thomas Robert Malthus is one of the most influential writers in history on the topic of population, especially his book Essay on the Principle of Population as it affects the future improvement of society; With remarks on the speculations of Mr. Godwin, M. Condorcet, and other writers. Malthus believed that human beings are ”impelled” to […]

Migration: Internal

Internal migration is typically defined as the permanent residential relocation of an individual or population from one geographical unit to another within a particular country. Examples of internal migration include a move between regions of a country, between a rural area and a city, from one city to another, and between the neighborhoods of a […]

Migration: International

International migration refers to the movement of people from one country to another on a permanent or semi-permanent basis. While people have migrated for centuries, international migration started with the carving up of the world into territorially bounded sovereign countries, a process that dates to the start of the Westphalian state system in the seventeenth […]