Which of the following is a correct statement about demography?

The correct option is: Demographic change is based on economic, social and cultural variables.

Demography is the scientific study of human populations, primarily focusing on their size, structure, development, and distribution. Demographic changes—which refer to shifts in population characteristics such as birth rates, death rates, migration patterns, and aging—are not isolated events. Instead, they are deeply influenced by a complex interplay of various external factors:

1. Economic Variables: Economic development, employment opportunities, and income levels significantly affect family planning decisions and migration. For example, higher economic growth often leads to better career opportunities for women, which can delay marriage and childbirth, thereby lowering fertility rates. Conversely, people often migrate from economically depressed regions to areas with better job prospects.
2. Social Variables: Social factors include education levels, healthcare access, and urbanization. Increased access to quality healthcare reduces infant mortality rates, which historically leads to a subsequent decline in overall birth rates. Education, particularly for women, is one of the strongest social predictors of lower fertility rates globally.
3. Cultural Variables: Cultural norms, religious beliefs, and traditional values shape societal attitudes toward family size, marriage age, and gender roles. For instance, in societies where large families are culturally valued or where religious beliefs discourage artificial contraception, birth rates tend to remain higher.

Let us evaluate why the other options are incorrect:
- "Demographic change is purely biological" is incorrect because, while birth and death are biological processes, the rates at which they occur are strongly governed by social, economic, and behavioral choices.
- "Demographic data is a static data for a population" is incorrect because populations are dynamic and constantly changing due to continuous births, deaths, and migration.
- "Population explosion does not happen in every country", while factually true in a literal sense, does not define the fundamental, comprehensive nature of demography as effectively as the correct option, which highlights the underlying drivers of demographic change.