Of Human Population | Demography: The Study

Most modern demographic analysis is framed by the , which describes the historical shift from high birth and death rates to low ones as societies develop.

: The movement of people across borders. While net migration is zero at a global level, it is a critical driver of "fast demography" at the national level, often offsetting natural population declines in developed countries. The Demographic Transition Model (DTM) Demography: The Study of Human Population

: Both rates are low; the population stabilizes. Most modern demographic analysis is framed by the

: The actual reproductive performance of a population. Demographers measure this through the Total Fertility Rate (TFR) —the average number of children a woman would have in her lifetime. Currently, the world is nearing the "replacement level" of 2.1, below which a population eventually begins to shrink. The Demographic Transition Model (DTM) : Both rates

: The incidence of death in a population. Improvements in healthcare and nutrition have led to a significant increase in global life expectancy, which rose by over eight years between 1995 and 2026.

Demography is the scientific study of human populations, primarily focusing on their size, composition, and spatial distribution, as well as the dynamic processes that drive change—, mortality , and migration . It is a multidisciplinary field, drawing on statistics, sociology, economics, and biology to analyze how individual life events shape global and local trends. The Core Pillars of Demography

: High birth and death rates; population size remains stable but low.