W3 Demography

• Demography is the statistical study of human population.
• Demography encompasses the study of the size, structure and distribution of populations.
• Demography:

  • spatial and/or temporal changes in response to birth, migration, aging and death
• Demographics refers to characteristics of a population.
• Population is the study of the character, number, and distribution of living organisms residing in or migrating through particular places.
• FACTORS IN POPULATION:

  • Social and Biological Science
  • Size of Breeding Group
• 3 PRINCIPAL USES of Population Data in health administration:

  • The computation of vital and health statistics rates and ratios.
  • Setting up coverage of activities.
  • Setting up norms for assignment of health facilities, staff and funds.
• Estimates of Population Size

  • Continuous Population Registration

  • Consist of registering births, deaths, emigration and immigration, making necessary additions and subtractions to the existing population.
• Surveys- Simple way of estimating the number of population in a smaller area.
• • Mathematical Estimates:

  Maybe done by means of Arithmetic and Geometric increase method
• Arithmetic Increase Method - it is assumed that the population increases at a constant amount per year.
• Geometric Increase Method - assume that population increases at a constant rate per year.
• DEMOGRAPHIC ANALYSIS

  • can be applied to whole societies or to groups defined by criteria.

  – education, nationality, religion and ethnicity.
• demography is considered a field of sociology
• Formal Demography

  –limits its object of study to the measurement of populations processes
• Formal Demography

  –it comprises "a set of techniques by which data collected in censuses, surveys and vital registration systems about age, sex, births, deaths, migrations and marriages.
• Social Demography

  –population studies analyze the relationships between economic, social, cultural and biological processes influencing a population.
• Population studies

  –encompasses the study of fertility, mortality and migration.
• CENSUS is the common DIRECT method of collecting demographic data.
• CENSUS is conducted by a national government and attempts to enumerate every person in a country.
• CENSUS occur every 10 years.
• CENSUS is NOT the best source of data on births and deaths.
• Census is defined as an official and periodic enumeration of population.
• Census –determining and explaining TRENDS in terms of population changes and planning programs and services.
• Vital statistics data

  – collected continuously and summarized on an ANNUAL basis.
• 2 WAYS of Assigning People when census is being taken:

  • De jure method
  • De facto method
• De jure method is done when people are assigned to the place WHERE THEY USUALLY LIVE regardless of where they are at the time of census.
• De facto method is done when the people are assigned to the place WHERE THEY ARE PHYSICALLY PRESENT AT THE TIME of the census regardless of their usual place of residence.
• Sample Survey

  –obtained data come from a SMALL number of people proportionate to the total population, the results will always be GENERALIZED for the whole population.
• Registration systems

  – collected by the civil registrar’s office deal with recording vital events in the community.
• Vital events

  – refer to births, deaths, marriage, divorces and the like.
• Censuses

  – collect information about families or households
• Censuses

  – occupation, and geographical location.

  – characteristics as age, sex, marital status, literacy/education, employment status
• Censuses

  • collect data on migration (or place of birth or of previous residence), language, religion, nationality (or ethnicity or race), citizenship.
• Censuses

  • used as a direct source of information about fertility and mortality.
• Two methods of data collection:

  • direct
  • indirect
• Direct data

  • come from vital statistics registries that track all births and deaths.
  • changes in legal status (marriage, divorce)
  • migration (registration of place of residence)
• registry statistics are the BEST method for estimating the number of births and deaths
• Indirect methods of collecting data are required in countries where full data are not available.
• Sister method technique

  – where survey researchers ask women how many of their sisters have died or had children and at what age.