Demography is a broad social science discipline concerned with the study of human populations. Demographers deal with the collection, presentation, and analysis of information relating to the basic life-cycle events and experiences of people. This discipline emphasises the theoretical and empirical investigation of population processes, and the study of their determinants and consequences. Practitioners frequently draw on related disciplinary areas: sociology; economics; political science; anthropology; psychology; public health and ecology; to illuminate their analyses. Students may also explore biological and biosocial aspects of fertility and mortality in areas such as reproductive health and epidemiology. The field of Demography is also concerned with the broader nature of social and economic change, and with the impact of demographic change on the natural environment.