DEMOGRAPHY Flashcards
is the scientific study of the characteristics of human populations in terms of structure, distribution, growth & developments, and spatial and/or temporal changes in them in response to birth, migration, aging and death.
Demography
Seeks reason or explanations why such conditions are changing
Demography
It focuses on:
o changes in population size (growth or decline)
o composition of the population (structure – age, sex distribution of population)
o distribution of population in space.
o size of population – total no. of population present in a geographical area.
It is the study of the character, number, and a distribution of living organisms residing in or migrating through particular places.
POPULATION
Major Elements
Population Size
Population Composition
Population Distribution
What are under the population size?
Estimate in Population Size
Demographic Analyses
Data and Methods
Three Processes Population can change
Method of measuring the Population size
What are under the population composition?
Age Composition of a Population
Sex Composition of a Population
Age and Sex Composition of a Population
What are under the population distribution?
Urban-rural distribution
Crowding index
Population Density
Continuous Population Registration
Consist of registering births, deaths, emigration and immigration, making necessary additions and subtractions to the existing population.
Estimate in Population Size
Simple way of estimating the number of population in a smaller area.
Surveys
What are the mathematical Estimates?
Arithmetic Increase Method
Geometric Increase Method
it is assumed that the population increases at a constant amount per year.
Arithmetic Increase Method
assume that the population increases at a constant rate per year.
Geometric Increase Method
- It can be applied to whole societies or to groups defined by criteria.
o Education, nationality, religion and ethnicity.
Demographic Analyses
is considered a field of sociology.
Demography
Types of Demographic Analyses
Formal Demography
Social Demography
Population Studies
o It limits its object of study to the measurement of population’s processes.
o 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.
Formal Demography
o Population studies analyze the relationships between economic, social, cultural and biological processes influencing a population.
Social Demography
o Encompasses the study of fertility, mortality and migration.
Population Studies
o It is the common direct method of collecting demographic data.
o Conducted by national government and attempts to enumerate every person in a country.
o Not the best source of data on births and deaths.
o It is defined as an official and periodic enumeration of population.
o Determining and explaining trends in terms of population changes and planning programs and services.
Census
Census can be conducted on the following basis:
De jure method
De facto method
conducted based on permanent place or residence regardless of where they are at the time of census. Operation census period is defined and counting of population is completed within this period. The period taken is generally 2 or 3 weeks.
De jure method
people are counted in place where they are physically present at the time of census regardless of their usual place of residence. This type of census is conducted at night because it is presumed that all household are present on their residence during that time.
De facto method
Collected continuously and summarized on an annual basis.
Vital Statistics Data
o Obtained data come from a small number of people proportionate to the total population.
o The result will always be generalized for the whole population.
Sample Survey
Collected by the civil registrar’s office deal with recording vital events in the community.
Registration Systems
Three Processes Population can change:
Fertility Rate (birth rate)
Mortality (death rate)
Migration (emigration and immigration)
Involves the number of children that women have and is to be contrasted with fecundity (a woman’s childbearing potential).
Fertility rate (birth rate)
It is the study of the causes, consequences, and measurement of processes affecting death to members of population.
Mortality (death rate)
Refers to the movement of persons from an origin place to a destination place across some re-define, political boundary.
Migration (emigration and immigration)
specifically used to indicate people leaving the country in question.
emigration
specifically used to indicate people arriving at the country being discussed.
immigration
Method of measuring the Population size:
By determining the increase in the population resulting from excess of births compared to deaths.
Natural Increase
Rate of Natural Increase
Crude Birth Rate
Crude Death Rate
Method of measuring the Population size:
To determine the increase in the population using data obtained during two census periods.
Absolute increase per year
Relative Increase
refers to the difference between the number of births and the number of deaths in a given period, typically a year. It does not account for migration and focuses solely on the balance between births and deaths.
Natural Increase
Formula for Natural Increase
Natural Increase = Number of Births - Number of Deaths
measure of population growth based on the difference between the crude birth rate (CBR) and the crude death rate (CDR). It shows how much a population is growing or declining, excluding migration.
Rate of Natural Increase
Formula for Rate of Natural Increase
Crude Birth Rate - Crude Death Rate / 10
demographic measure that represents the number of live births occurring among the population of a given area during a specific year. It is usually expressed per 1,000 people in the population.
Crude Birth Rate
Formula for Crude Birth Rate
(Number of Births in a year / Total Population) x 1,000
demographic measure that indicates the number of deaths occurring among the population of a given area during a specific year. It is usually expressed per 1,000 people in the population.
Crude Death Rate
Formula for Crude Death Rate
(Number of Deaths in a year / Total Population) x 1,000
Method of measuring the Population size:
To determine the increase in the population using data obtained during two census periods.
Absolute Increase per year
Relative Increase
refers to the actual number of people added to the population over a year, without expressing it as a percentage or rate.
Absolute increase per year
Formula for Absolute Increase per year
Population at end of year - Population at start of year
refers to the percentage change in a value (such as population, revenue, etc.) compared to its initial value. It is a way of measuring how much something has grown or changed relative to where it started.
Relative Increase
Formula for Relative Increase
(Population at end of year - Population at start of year / population at start of year) x 100
Refers to the demographic makeup of a population, which includes various characteristics that define individuals within that population.
Population Composition
These characteristics of population composition can include:
Age
Sex/Gender
Ethnicity/Race
Occupation
Education Level
Marital Status
Income level
Religion
Household Size
Migration/origin
Distribution of people across different age groups, such as children, young adults, middle-aged individuals, and the elderly.
Age
The ratio of males to females in the population.
Sex/Gender
The distribution of various ethnic or racial groups.
Ethnicity/Race
Types of jobs or industries people are employed in, like agriculture, services, or technology sectors.
Occupation
The highest level of education attained by individuals in the population.
Education Level
The proportion of married, single, divorced, or widowed individuals.
Marital Status
The distribution of individuals across different income brackets.
Income level
Religious affiliations or beliefs present within the population.
Religion
The average number of individuals per household.
Household size
Whether people are native to the area or immigrants from other regions or countries.
Migration/origin
The age that divided the population into two numerically equal groups, meaning half of the population is younger than this age and the other half is older. It’s an important demographic indicator used to understand the age composition of a population.
Median Age
Median Formula
L + ( (N/2 - F) / f ) x h
Median Formula where:
L stands for?
Lower boundary of the median age group
Median Formula where:
N stands for?
Total Population
Median Formula where:
F stands for?
Cumulative frequency of the groups before the median age group
Median Formula where:
f stands for?
frequency (number of people) within the median age group
Median Formula where:
h stands for?
Width of the age interval (difference between upper and lower bounds of the age group)
When examining the median age of a population, certain factors influence its composition:
indicates an older population, which may suggest lower birth rates, longer life expectancy, and potentially an aging society.
High median age
When examining the median age of a population, certain factors influence its composition:
reflects a younger population, usually a result of higher birth rates and possibly shorter life expectancies.
Low median age
o Demographic measure that compares the number of dependents (people who are typically not in the labor force) to the working-age population.
o It helps to assess the pressure on the productive population and is usually expressed as a percentage.
o The resulting number is the number of dependents that need to be supported by every 100 people in the economically active age-group.
Age Dependency ratio
Components of age dependency ratio:
Dependent population
Working-Age population
Population aged 0-14.
Youth Dependency Ratio
Population aged 65 and older.
Elderly Dependency Ratio
Typically defined as people aged 15-64.
Working-Age population
Formula of Age Dependency Ratio:
(Population aged 0-14+ Population aged 65 and older / Population aged 15-64) x 100
- Refers to the distribution of individuals based on their sex (typically male and female).
- Understanding the sex composition is crucial for demographic analysis, social planning, and policy-making.
- Computed by dividing the number of males by the number of females using a factor of 100.
- Interpreted as the number of males for every 100 females in the population.
Sex Composition of Population
Formula for Sex Ratio
(Number of Males / Number of Females) x 100
- Refers to the distribution of individuals across different age groups and genders within a given area.
- This composition is often visualized using age-sex pyramids, which can reveal trends in population growth, aging, and gender balance.
Age and Sex Composition of a Population
o One of the most popular visual representations of data in demography.
o Graph which displays simultaneous description of the age and sex composition of a population.
o The number or proportions of males and females in each age group are represented using horizontal bars.
Population Pyramid
Components of a Population Pyramid:
Each bar represents a specific age group, with the length of the bar corresponding to the number of individuals in that groups. The age groups are usually displayed in five-year intervals (e.g., 0-4, 5-9, etc.) from the bottom to the top.
Horizontal Bars
Components of a Population Pyramid:
typically represents age groups, with younger cohorts at the bottom and older cohorts at the top.
Vertical Axis
Components of a Population Pyramid:
The left side of the pyramid usually represents males, while the right side represents females. The bars on each side can show the relative size of each sex in each age group.
Sex Distribution
Stages of Sex Distribution
- High Stationary
- Early Expanding
- Late Expanding
- Low Stationary
- Constrictive
What stage is…
- Concave side slopes
- High Birth Rate
- High death rate
- Short life expectancy
- Rapid fall in upward age
- High Stationary
What stage is…
- Straight or Still side/ Triangular shape
- High Birth Rate
- Falling death rate
- Slightly longer life expectancy
- More people living into middle age
- Early Expanding
What stage is…
- Dome-shape or bell-shaped
- Declining Birth rate
- Low death rate
- Long life expectancy
- More people living to old age
- Late Expanding
What stage is…
- Barrel Shape/ stable/ stationary
- Low birth rate
-Low death rate - Longer life expectancy
- Higher dependency ratio
- Low Stationary
What stage is…
- Urn shape or bulb shape
- Very low birth rate
- More Death rate
- Population declining
- Increasing Old age dependency
- Constrictive
- It can be described in terms of urban-rural distribution, population density and crowd index.
- The measures help how resources can be justifiably allocated based on concentration of population in a certain place.
Population Distribution
o Simply illustrates the proportion of the people living in urban compared to rural areas.
Urban-rural distribution
o Describe by which a communicable disease will be transmitted from one host to another susceptible host.
o This is described by dividing the number of persons in a household with the number of rooms used by the family for sleeping.
Crowding index
Most common Formula for crowding index
Number of Persons / Number of Rooms
A crowding index of … indicates that there is one person per room, which is often considered a threshold for adequate housing.
1.0
An index … suggests overcrowding, meaning more than one person is sharing a room.
greater than 1.0
An index … indicates that there are more rooms than people, suggesting ample living space.
less than 1.0
o Determine how congested a place is and has implication in terms of the adequacy of basic health services present in the community.
o It can be computed by dividing the number of people living in a given land area.
Population Density
Formula for Population Density
Total population / Total area
