What does demography study?

Demography is the statistical study of populations, particularly with respect to their size, distribution, density, and changes over time due to births, deaths, migrations, and aging. This discipline often analyzes demographic data to discern trends and patterns related to population growth and decline, which can be crucial for understanding social, economic, and environmental factors affecting societies.

By focusing on statistical data, demography allows researchers to generate insights about population structures and forecasts that support policy-making, resource allocation, and planning efforts in various fields, including public health and urban development. This foundational understanding of human populations can highlight important societal trends and challenges.

The other choices, while related to elements that might affect or describe populations, do not encompass the primary focus of demography, which is strictly on the statistical aspects and dynamics of populations as a whole.