Human Population

age structure

Percentage of the population (or number of people of each sex) at each age level in a population.

Crude Birth Rate (CBR)

the number of live births yearly per thousand people in a population

Crude Death Rate (CDR)

The total number of deaths in a year for every 1000 people alive in the population.

cultural carrying capacity

the maximum number of people who could live in reasonable freedom and comfort indefinitely, without decreasing the ability of the earth to sustain future generations.

demographic transition

The process of change in a society's population from a condition of high crude birth and death rates and low rate of natural increase to a condition of low crude birth and death rates, low rate of natural increase, and a higher total population.

family planning

Providing information, clinical services, and contraceptives to help people choose the number and spacing of children they want to have.

infant mortality rate

The total number of deaths in a year among infants under one year old for every 1,000 live births in a society.

life expectancy

The average number of years an individual can be expected to live, given current social, economic, and medical conditions. Life expectancy at birth is the average number of years a newborn infant can expect to live.


movement of people from one place to another

population change

Increase or decrease in the size of a population. It is equal to (Births + Immigration) - (Deaths + Emigration).

Replacement level fertility rate

average number of children a couple must have to replace themselves.

Total Fertility Rate (TFR)

an estimate of the average number of children that each woman in a population will bear throughout her childbearing years (ages 15-44)