Unit 22 Population

1. Why are sociologists interested in demographic data?

Population data help us to understand social life. Sociologists are interested in relating these data to age, income, education, race, and other factors. Sociologists are particularly interested in the numbers of births, deaths, and migrations. Changes in these figures both reflect and cause changes in social institutions. Population data also are relevant when we assess the adequacy of a society's environmental resources and the impact of population numbers on an ecological setting. Although survey data are useful for establishing public opinion and attitudes, the conclusions of these surveys become more meaningful when placed in the context of changes in the demographic structure of a society.

Demography is the study of how births, deaths, and migration affect the composition, size, and distribution of populations. Demography has two aspects: 1) it is used in a broad way to describe social structure and 2) it is used in a more micro way to understand individuals and their actions. That is, demography has both structural and action perspectives.

2. How do sociologists study populations?

Demographic analysis requires accurate and detailed information from a variety of sources so that population distributions can be assessed and future trends can be projected. The most important source of demographic data is the national census, which counts the total number of people as well as the numbers of people in various regions. Many nations conduct elaborate censuses periodically, but a full census is not always practical. Many less developed nations have no established census programs. In such situations, demographers use surveys and ethnographic methods to arrive at indications of population patterns. Censuses often are the subject of political controversy because they may have implications for the distributions of power.

The U.S. Census may not be entirely accurate. For example, about seven million people were overlooked in the 1980 census. Immigrants, particularly illegal aliens, are undercounted. Under-counts also are prevalent in poor neighbourhoods. Overall the poor, the young, aliens, males, and minorities are more difficult to count than other people; these categories represent the more mobile groups in our society. Other problems with the census include the wording of questions, the opinion that the census violates privacy rights, and reservations regarding the confidentiality of the data.

The Census Bureau is interested primarily in the number of births, deaths, and migrations. The crude birthrate is the number of births per 1, 000 people per year. This rate has varied dramatically over the last 50 years.

Sociologists also distinguish between fecundity and the fertility rate. The former reflects the biological potential for reproduction; the latter reflects the number of actual births per 1, 000 women between the ages of 15 and 44. Birth and fertility rates in the United States have been declining steadily for many years. The rate of decline varies according to socioeconomic status. Since 1972 the U.S. birthrate has been below its replacement level of 2.1 children per woman of childbearing age. In addition, family size was decreased because of the high cost of bearing and rearing children, women's increased participation in the labour force, and the tendency for career-minded women to marry later and to postpone starting families. Several factors influence a nation's birthrate: 1) the desire for children, 2) the number of fertile women in the population, 3) the marriage rate and age at marriage, and 4) the availability of effective contraceptives.

The crude death rate is the number of deaths per 1, 000 people during a given year. This rate varies considerably by age and ethnicity. The infant mortality rate is the number of deaths among infants under one year of age per 1, 000 live births in a given year. Although the infant mortality rate of 10.8 in 1984 is the lowest ever recorded in this country, it is still higher than in several other developed countries. Life expectancy is the average number of years of life remaining for an individual of a given age; life span is the maximum number of years a human being can live. Life expectancy has increased dramatically in the last century; life span has not. Changes in mortality have had the strongest impact on the demographic history of the human population.

The migration rate is the difference between the number of people who leave a place and those who arrive each year, per 1, 000 people. Emigration is migration from one's native land; immigration is migration to a new country. Internal migration—movement within a country—is also an important demographic phenomenon. People migrate for a variety of reasons including disasters, political and religious persecution, and the desire for adventure. The United States has only Five percent of the world's population but takes in about 50 percent of the world's immigrants.

About 17 percent of the U.S. population moves every year; more than six percent move to a new state or country. Those who move still tend to move west. The climate, the availability of space, and other resources have attracted businesses and people who want to live in an area with more amenities. This shift in regional population distribution has caused a shift in regional political power.

Many cities are losing population to adjacent suburbs, which are the fastest-growing places of residence. In addition, black Americans increasingly have become urban dwellers. During the 1970s, Americans frequently responded to the problems of urban density by moving to smaller towns and rural areas. This growth in small towns and rural areas marked a major turning point in the region­al development of the United States.

The impact of the population dynamics outlined above can be summarized in the population pyramid. This pyramid graphically portrays the age distribution of a society and usually the sex distribution as well. Population pyramids for different points in time show the changes in the age structure in a society. Clearly, population distributions reflect structural forces at work.