Ch. 2 Key Issue 3

Demographic Transition
Has a beginning, middle, end, and is irreversible.
Four stages. You cannot go back a stage.
Demographic Transition: Stage 1(low growth)
CBR's and CDR's varied, making growth virtually 0%. No more countries in this stage.
Agricultural Revolution
domestication of animals and such
Demographic Transition: Stage 2(high growth)
CDR falls, and CBR stays the same. NIR is high so pop. grows quickly.
Industrial Revolution
conjunction of major improvements in industrial tech. that transformed process of manufacturing goods and delivering them to market
Medical Revolution
Medical tech in europe and N.A. diffused. People lived longer.
Demographic Transition: Stage 3 (moderate growth)
When CBR drops sharply CDR keeps falling but at a slower rate than stage 2, so rate of NIR is more modest.
Demographic Transition stage 4 low growth
CBR declines so it equals CDR. NIR is 0.
Social customs play a part: AKA people don't want kids.
Zero population growth(ZPG)
NIR is zero.
total fertility rate(TFR)
demographers define zero population growth as this. a TFR of 2.1 makes ZPG.
Population in a country is influenced by dem. trans. in two ways:
percent of population in each age group, and distribution of males and females
population pyramid
percent of total population in five year groups with youngest at base and oldest on top.
Males on left, females on right.
dependency ratio
number of people too young or old to work, compared to number of people in productive years.
as countries pass through stages of demographic transition, percentage of _____ increases
Sex ratio
percent of males per 100 females.
males generally outnumber.
societies with a high rate of immigration usually have more