How is 'demography' best defined?

The best definition of 'demography' is the statistical study of populations. This field involves analyzing various characteristics of populations, including size, distribution, density, age structure, fertility rates, mortality rates, and migration patterns. By employing statistical methods, demographers can identify trends and changes over time, which is crucial for understanding social dynamics and planning for future needs in areas such as healthcare, education, and urban development.

The other options, while related to the broader study of society, do not encapsulate the essence of demography. The study of economic systems focuses on how resources are allocated in societies, political trends concentrate on governance and power structures, and the examination of individual behaviors pertains more to psychology or sociology rather than the collective statistical analysis inherent in demography. Therefore, the emphasis on statistics and population characteristics distinctly defines demography as a field of study.