The demographer applies different research methods (surveys, statistical analyzes, census, etc.) to study a given population under different aspects (size, geographical distribution, structure by age, sex, education, employment, income, marital status, etc.) He tries to explain the causes of certain demographic phenomena such as, for example, the drop in the birth rate, the aging of populations, the increase in single-parent families, etc. He tries to determine the consequences of these phenomena on social functioning and tries to identify future trends in the evolution of populations The demographer carries out his research according to a rigorous methodology so that his work serves to guide many related decisions For example: development of policies and programs of social security, employment or retirement or the planning of health, education, transport or urban development services. public structures or private companies, he is consulted by decision-makers in his sector and participates in the writing of numerous studies.In addition to a very good level in maths, statistics and computer science, he must be an expert in economic analysis and sociological. Sense of teamwork and a spirit of analysis and compulsory synthesis. Employers can be, for example, ministries, a national or international or even regional observatory, public research institutes, local authorities (civil servant or contractual status). The demographer can also be in education or a researcher. There are also some opportunities in the private sector (architectural firm, insurance companies, etc.). In general, the outlets are quite limited.