Chapter 23: Population, Aging, and Social Demography

Demographers

social scientists who study populations and pop. trends

census

count of everyone residing in certain location

Reasons to study population

1. helps estimate future social trends for planning

2. determining political boundaries

3. can have high effect on national + regional economies

Population size (change) determined by 

births - deaths + immigration - emigration 

fertility

birthrate measured by number of live births per woman of childbearing years

mortality

deaths

migration 

immigration and emigration 

population based trends

1. racial + ethnic composition

2. marriage and family

3. employment issues

4. life expectancy

First demographic transition

transition in a country or region from a period of high fertility + high mortality to low fertility + low mortality

once fertility has declined…

it does not reverse!

How does the first demographic transition work?

1. mortality declines first

2. increase in population 

3. fertility declines 

4. Post: slow population growth 

Total fertility rate

number of kids an average woman has in her lifetime

replacement fertility 

number of kids per woman necessary to replace population 

age pyramids

plot size of population in each age group for men and women

population momentum

happens when women of childbearing age is large or growing even though fertility rate declined

baby boom

Post WWII (1946-1964)

cohort

people born during same time period

Factors influencing fertility

1. declines in infant mortality

2. economic dev.

birth control

acceptance that people should exercise control over fertility = less inintended kids

childrearing

fertility declines due to cost and benefits of having and raising kids

norms and values

fertility decline due to second demographic transition

Second demographic transition 

increase in divorce, premarital sexual activity, increased cohabitation, and out of wedlock kids

Epidemiology

study of health related events in populations, characteristics, causes, and consequences

epidemiological transition

transition of population of health conditions from infectious diseases to health conditions from chronic disease

Life Expectancy 

average number of years a population at some age can expect to live