Topic: The Demographic Transition Model Aim: For what reasons do countries undergo a demographic transition?

The Demographic Equation: Formula which determines by how much a population will grow over a given time. Start with current population, add births expected between now and when you’re predicting, subtract the number of deaths, add immigration, and subtract emigration. Essentially, you add people coming in and subtract people leaving!

The Demographic Transition Model: Consists of four stages, which move from high birth and death rates, to declines first in death rates then in birth rates, and finally to a stage of low birth and death rates. Every country is in one of these stages Irreversible process – once a country moves from one stage to another, it does not ever go back.

Stage 1: Low Growth Most of Earth’s history spent in this stage, however no country remains there today Hunting/gathering nomadic peoples. NIR about zero- approx. ½ million people High birth & death rates 8000 B.C. - Agrarian (aka-Agricultural, Neolithic) Revolution cause increase in population. However, climate/war/disease caused CDR to rise.

Stage 2: High Growth 1750 A.D. - population grew 10X faster than in previous years due to Industrial Revolution CDR decreases, CBR remains the same as stage 1. Due to this, NIR is high and population increases During IR, public improvements in health, sanitation, and food supplies - people living longer Greater increase of children living longer, thus age structure becomes more youthful Stage did not diffuse to Africa, Asia, or Latin America until around 1950 - 150 years after Europe & North America

Stage 2: High Growth (continued)… Africa, Asia, and Latin America pushed into stage 2 by Medical Revolution - access to drugs, medicine This decreased many causes of death in LDC’s

Stage 3: Moderate Growth Occurs when CBR drops severely - people have fewer children for various reasons CDR continues to fall, but at a slower rate than stage 2 Population grows because CBR still greater than CDR NIR is smaller than in stage 2 due to smaller gap between CBR and CDR Malaysia

Stage 3: Moderate Growth (continued)… Europe & North America made transition first half of 20th Century Asian, Latin America moved in recent years Most of Africa still in stage 2!

Stage 4: Low Growth CBR declines to zero where it equals CDR, and NIR approaches zero. Called Zero Population Growth (ZPG) Women in this stage enter labor force rather than remaining home Birth control more available

http://www.youtube.com/watch?v=0dK3mL35nkk

Hans Rosling – 200 Countries, 200 Years, 4 minutes http://www.youtube.com/watch?v=jbkSRLYSojo

Summary: Free Response