demography: population estimation

Population

It is the study of the character, number, and a distribution of living organisms residing in or migrating through particular places.

Surveys

Simple way of estimating the number of population in a smaller area.

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.

Fertility, Mortality, Migration

population may change due to

Fertility

Involves the number of children that women have and is to be contrasted with fecundity

Mortality

It is the study of the causes, consequences, and measurement of processes affecting death to members of the population.

Migration

The movement of persons from an origin place to a destination place across some pre defined, political boundary

Demography

It is the statistical study of the human population

Formal, Social, Population

types of demographic analysis

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

Defined as an official and periodic enumeration of population

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

Population Estimation

A process of calculating or predicting the number of people in a specific area at a given time

Inter-census Estimation

is for a date between two census takings and usually takes the results of the two censuses into account

Post-Census

estimates are typically conducted for the current year.

Population Data

Vital Statistics Data

Sample Survey

Registration Systems

Social-Economic Censuses

types of data

Population Census

Conducted by a national government and attempts to enumerate every person in a country that occurs every 10 years

Vital Statistics Data

Collected continuously and summarized on an annual basis.

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 to record vital events in the community

Social-Economic Censuses

Collect information about families or households

Direct and Indirect

two methods of data collection

Direct Data

Come from vital statistics registries that track all births and deaths.

Indirect Data

Collecting data is required in countries where full data are not available.

Arithmetic Method

Geometric Method

Exponential Method

methods of population estimation

Arithmetic Method

Assumes a constant number of people are added every year

Geometric Method

Assumes the population grows at a constant rate (percentage) each year.

Exponential Method

Assumes the population grows at a constant rate (percentage) each year.

Annual Growth Rate

Calculated using geometric and exponential methods to find how fast the population increases each year (in percentage)

Absolute Increase Per Year

Shows the exact number of people added each year (difference between two population counts)