Demography is the science dealing with the study of population and changes made to it.
The study population is carried out through clarifying the population, processes of movement (migration) and the natural movement of population. The latter is a major factor in the ever-changing population. Natural population growth, which is determined by the difference between the birth rate and mortality is an indicator, which mainly characterizes the ongoing shifts in population.
The population determine periodic population censuses (see), which give an accurate idea of the number of population at the time of the census, its composition by sex, age, nationality, level of education and other census Data are needed for planning in all sectors of the economy, including in the field of cultural construction.
Of great importance are the changes in the number and composition of the population, resulting from migration processes. The peculiarity of these processes in the USSR is planned basis, excluding the spontaneity, which creates unfavorable sanitary condition of the population.
The most important topic of demography is the study of reproduction, natural movement of population processes in the birth rate (see), child and overall mortality (see). These processes not only reflect changes in the number and composition of the population, but are of great importance for assessment of the health status of the population. Especially important in this regard are the mortality rates of children under the age of 1 year (see child mortality).
Cm. also, so-3, PL., section "Health".