population & migration

Crude Birth Rate (CBR)

The total number of live births in a year for every 1,000 people alive in the society.

Crude Death Rate (CDR)

The total number of deaths in a year for every 1,000 people alive in the society.

Natural Increase Rate (NIR)

The percentage by which a population grows in a year, calculated as (CBR - CDR) / 10

Doubling Time

The number of years needed for a population to double in size, calculated using the Rule of 70: 70 / NIR.

Net Migration Rate (NMR)

The difference between the number of immigrants and out-migrants per 1,000 population.

Demographic Equation

The formula used to calculate total population growth rate: (CBR - CDR) + (Immigration Rate - Emigration Rate)

Fecundity

The biological capability of a woman to conceive, typically occurring between ages 15 and 45.

Total Fertility Rate (TFR)

The estimated average number of children a woman will have throughout her childbearing years.

Replacement-Level Fertility

A TFR of 2.1, which maintains a stable population without growth or decline.

Infant Mortality Rate (IMR)

The annual number of deaths of infants under one year of age per 1,000 live births.

Life Expectancy

The average number of years a newborn infant can expect to live based on current mortality levels.

Dependency Ratio

The ratio of people too young (under 15) or too old (over 65) to work, compared to the number of people in their productive working years (15–64).

Dependency Ratio Formula

((% under 15) + (% over 65)) / (% between 15 and 64) * 100.

Pronatalist (Expansive) Policy

Government policies designed to promote reproduction and encourage larger family sizes (e.g., tax breaks).

Antinatalist Policy

Government policies designed to reduce fertility rates and control overpopulation (e.g., China's former One-Child Policy).

Eugenic Policy

Population policies designed to favor the reproduction of a specific demographic or cultural group within a country.

Female Infanticide

The deliberate killing of female infants, often an unintended consequence of strict antinatalist policies in patriarchal societies.

Demographic Momentum

The tendency for a population to continue growing after fertility rates fall because a large young cohort is entering childbearing years.

Maternal Mortality Rate

The annual number of female deaths per 1,000 live births from pregnancy-related causes or management.

Gender Equity

Equal fairness and welfare for women across education, healthcare, social roles, and political power.