Birthrate—See fertility measures.
Demography—The scientific study of human population, especially its dynamics, as reflected in fertility, mortality, and migration.
Economies of scale—Reductions in average cost resulting from increased production.
Ecosystem—The entire set of relationships between the physical environment and the living populations of plants, animals, and human beings that inhabit the environment and depend upon it for life support. The environment provides living space, energy and raw materials to the biological community, and the community is structured in such a way as to allocate space and the flows of materials and energy among the many species that live together the environment.
Fertility measures—Three principal measures of fertility are referred to in this report:
Birthrate—The number of children born during a year per 1,000 total population at the middle of that year. In 1970, there were 18 births per 1,000 population.
Fertility rate—The number of children born in a year per 1,000 women of reproductive age, or any age group within the childbearing range. In 1970, there were 88 births per 1,000 women 15 to 44 years old.
Total fertility rate—This measure expresses births in a year in terms of the implied average number of children per woman over lifetime. The measure is calculated by summing the fertility rates for each age of women in the childbearing years. In 1970, the total fertility rate averaged between 2.4 and 2.5 children per woman.
Fiscal year—Runs from July 1 through June 30; for example, Fiscal year 1973 begins July 1, 1972, and ends June 30, 1973.
GNP (gross national product)—Measures the total goods and services output of the economy at market prices.
Growth ethic—The value that growth is good, as an index of progress.
Median age—The age which divides a population into two halves.
Metropolitan areas—Depending on the context and source, this refers to two somewhat different definitions:
(1) Historical data or 1970 data based on census materials refer to Standard Metropolitan Statistical Areas (SMSA’s); that is, one city with 50,000 inhabitants or more, or two contiguous cities with a combined population of 50,000, plus those adjacent counties which are functionally integrated with the central city. There are currently 243 SMSA’s in the United States.
(2) In the projections presented in Chapter 3, the term refers o functionally integrated areas of 100,000 population or more, composed of an urbanized area or central city of at least 50,000 people, and the surrounding counties. In New England, whole county areas are used in contrast to the official SMSA definition which is based on sub-county units.
Nonmetropolitan—The remainder of the country which is not included in the metropolitan classification.
Nuclear family—Parents and children only.
Pronatalist—Describes laws and other public policies, and other features of society such as informal social pressures and cultural expectations, which directly or indirectly encourage people to have more children.
Replacement fertility—The level of reproduction consistent with ultimate zero population growth. Under contemporary conditions f mortality, this averages out to 2.11 children per woman over a lifetime. The figure allows for deaths among women before they reach childbearing age, and also for the fact that slightly more males than females are born.
Rural—Rural population includes persons living in the open country or in towns of less than 2,500 people. It is subdivided in the rural farm population which comprises all rural residents living on farms, and the rural non farm population which includes the remaining rural population.
Stabilization—Zero population growth. See Chapter 12.
Unplanned fertility—Births which, just before conception, were not wanted at that time, but were wanted at some time in the future.
Unwanted fertility—Births which, just before conception, were never wanted at any time in the future.
Urban—The urban population comprises all persons living in urbanized areas (which contain at least one city of 50,000 and its surrounding closely settled area) and places of 2,500 or more population outside of urbanized areas.
Urban regions—Areas of one million population or more, comprised of a continuous metropolitan zone or system of metropolitan areas which may include a few enclosed or connecting nonmetropolitan counties.
Zero population growth—A condition in which population is not growing.