Formal demography simply refers to a mathematical study of such vital events as birth, death, migration, marriage and divorce. Social demography refers to a study of relationship between demographic phenomena on the one hand and social and economic phenomena on the other.
Changes due to shift from formal to social demography
The recent development in the field of demography have marked a shift from formal demography to social or substantive demography which takes into account not only the demographic components such as economic, social and cultures factors. The shift in demography has made these sciences more relevant and meaningful because demographic changes can be explained not only from social, economic and cultural perspectives. Social demography as a new branch of knowledge exists at the margin of demography and sociology.