The study of factors that affect birth and death rates in a population. This reflects the relative rates of factors that add individuals (birth and immigration) to those that eliminate them (death and emigration). Birth and death rates depend on sex and age. Population's sex ratio and age structure are its most important demographic features.

De*mog"ra*phy (?), n. [Gr. the people + -graphy.]

The study of races, as to births, marriages, mortality, health, etc.

© Webster 1913.