Demography – the study of the statistical characteristics of a population’s births, deaths, age/sex structure, spatial distribution, etc.

Demographics – the statistical characteristics of a population’s births, deaths, age/sex structure, spatial distribution, etc.

Crude Birth Rate (CBR) - The total number of live births in a year for every 1000 people alive in the society. The CBR of 20 means 20 babies are born over a one year period for every 1000 people in the country

 Crude Death Rate (CDR) - the total number of deaths in a year for every 1000 people alive in the society. A CDR of 40 means 40 people of any age died over a one year period for every 1000 people in the country

Natural Increase Rate (NIR) - The percentage by which a population grows (excluding migration) in a year.

Calculation: [(CBR-CDR)/1000]100 = %NIR

If the NIR is negative the population is decreasing.

Demographic Transition Model

Demographic Transition Model... a theory of population change over time. Seeks to explain population increases and decreases through variations in the birth rate and death rate. Based on observations of historical changes in parts of the economically more developed world (EMDW). A major criticism is its failure to take into account changes due to migration.

Demographic Transition ModelStage 1 CBR: very high, varied +33 of 1000CDR: very high, varied +33 of 1000NIR: no long term increase

Life style: hunting & gathering and early farming practices (1st Agricultural Revolution)

Historical Period: ≈ 8,000 BCE (modern man) – 1750 CE

Cause of Stage 2: Industrial Revolution - humans perfect farming methods and advent of varied technologies

NIR

Demographic Transition Model

NIR

Stage 2 CBR: very high, steady ≈40 per1000CDR: rapidly decline, <40 down to 15 per1000NIR: very high, sharp increase at start then slows

Life style: Agrarian(farmers); ability to cultivate reliable food source as well as medical revolution causes population explosion

Historical Period: 1750 CE – presentAll countries today are in at least Stage 2 through influence of MDCs

Cause of Stage 3: Cultural/Social changes resulting in lower CBR and subsequent Total Fertility Rate (TFR)

Demographic Transition ModelStage 3 CBR: rapidly decline, <40 down to 15 per1000

CDR: slow decline, <15 down to 5 per1000

NIR: steady decline toward ZPG

Life style: Urbanization, secondary and tertiary sector jobs prevalent. NEED for large family declines with change in economic structure and medical advances reducing IMR (culture mind-set changes)

Historical Period: 20th century – present

Cause of Stage 4: Cultural/Social change which caused lower CBR and Total Fertility Rate (TFR) creates Zero Population Growth (ZPG).

Demographic Transition ModelStage 4 CBR: very low, <10 per1000

CDR: very low, <10 per1000

NIR: ZPG; TFR of 2.1

Life style: Urbanized – changing family structure, changing role of women, birth control, etc.

Historical Period: 1990s – present

Stage 5?: No definition of what a stage 5 might be as this is a model based on historical retrospect…

Demographic Transition Model... a theory of population change over time. Seeks to explain population increases and decreases through variations in the birth rate and death rate. Based on observations of historical changes in parts of the economically more developed world (EMDW). A major criticism is its failure to take into account changes due to migration.