2.10: Key Terms Defined
Agricultural density: The number of farmers per unit area of arable land.
Arithmetic density: The population of a country divided by its total land area.
Carrying capacity : The maximum population size that the environment can sustain indefinitely.
Cartogram: map in which some thematic mapping variable—such as population—is substituted for land area or distance.
Cohort: A subset of a population, generally defined by an age range.
Crude birth rate: Total number of live births per 1,000 of a population in a year.
Crude death rate: Total number of deaths per 1,000 of a population in a year.
Demographic transition : The transition from high birth and death rates to lower birth and death rates as a country or region develops.
Dependency ratio: The ratio of those not in the labor force (generally ages 0 to 14 and 65+) and those in the labor force.
Doubling time: The period of time required for a population to double in size.
Ecological Fallacy: Characteristics about the nature of individuals are deduced from inference for the group to which those individuals belong.
Ecumene: The Greek concept of the habitable part of the Earth
Infant mortality rate: The number of infant deaths that occur for every 1,000 live births.
Life expectancy: The number of years that one is expected to live as determined by statistics.
Morbidity: The state of being diseased or unhealthy within a population.
Mortality: The number of people who have died within a population.
Overpopulation: A condition in which a place has outstripped its ability to provide for its own needs.
Physiological density: The number of people per unit area of arable land.
Population density: A measurement of population per areal unit, such as the world, a region, a country or other area.
Population momentum: The tendency for population growth to continue due to high concentrations of people in the childbearing years.
Population projection : An estimate of future population.
Population pyramid: Graphical illustration that shows the distribution of various age groups in a population.
Rate of natural increase: The crude birth rate minus the crude death rate. This rate excludes the effect of migration.
Replacement level: The average number of children a woman needs to have to ensure the population replaces itself. The number is roughly 2.1.
Total fertility rate : The average number of children that would be born to a woman over her lifetime.