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
: Birth rates begin to fall as society urbanizes and education (especially for women) increases. Demography: The Study of Human Population
: 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. Demography is the scientific study of human populations,
: 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) : The actual reproductive performance of a population
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.
: High birth and death rates; population size remains stable but low.