1. The Demographic Transition Blowin’ Up, yo.

2. Most of Humanity’s history on Earth has occurred during stage 1. Humans survived by hunting and gathering. A high and variable CBR. (fluctuating mid 30s to mid 40s) Despite advent of the Agricultural revolution c. 8000 BCE, human populations stayed in stage 1 because crops yields were unstable. A high and variable CDR. (fluctuating mid 30s to mid 40s) Death and birth rates were high and fluctuating because of the the uncertain food supplies and lack of medical technology. Therefore, a low and variable NIR. (fluctuating near zero) And a stable and relatively low population. STAGE 1: LOW GROWTH

3. The world stayed in stage one for about 10,000 years after the agricultural revolution. Population gains were modest. In 1750, several nations in Europe and North America entered the second stage of the Demographic Transition. CBR remains high and stable. (often in the 40’s) CDR declines steeply. (often into the teens) The countries entered stage two because of the INDUSTRIAL REVOLUTION. The new manufacturing industry produced massive wealth. In stage 2 countries, the wealth shifted the work patterns and created better health, sanitation and hygiene, thus lower death rates. Therefore, the NIR increases steeply. Often as high as 3% African, Asian and Latin American countries did not begin to enter stage 2 until about 1950. They did not enter stage 2 because of the industrial revolution but because of the MEDICAL REVOLUTION, which reduced their death rates. And the population begins to skyrocket. Some world countries are still in stage 2. Most of Sub-Saharan African countries are still in stage 2. STAGE 2: HIGH GROWTH

4. CDR fell in North American and European countries because of industrialization: A. Farms got machines, excess farmers moved to cities to work in factories B. Wealth began to spread… better living conditions, better nutrition from farms, better sanitation systems, better hygiene and medicine… LESS DEATH CDR fell in African, Latin American and Asian countries FOR A DIFFERENT REASON. The MEDICAL REVOLUTION from wealthy countries (not industries) diffused: A. better hygiene and medicine… LESS DEATH The GAP between high CBR and low CDR means MORE PEOPLE CDR fell in North American and European countries because of industrialization: A. Farms got machines, excess farmers moved to cities to work in factories B. Wealth began to spread… better living conditions, better nutrition from farms, better sanitation systems, better hygiene and medicine… LESS DEATH CDR fell in African, Latin American and Asian countries FOR A DIFFERENT REASON. The MEDICAL REVOLUTION from wealthy countries (not industries) diffused: A. better hygiene and medicine… LESS DEATH The GAP between high CBR and low CDR means MORE PEOPLE THE EMPHASIS

5. Stage 3 begins with sharp drop in CBR (often into teens) CDR continues to fall, but less steeply (often 0-10 range) Because of sharp drop in CBR, NIR begins to fall sharply. Often around 2% Therefore, Population still gains, but more slowly European and North American countries entered stage 3 in early 1900s. Many Asian and Latin American countries entered recently. Most African countries remain in stage 2. STAGE 3: DECREASING GROWTH

6. In Stage 2, CDR dropped because of change in TECHNOLOGY: Industrial technology in MDCs Medical technology in LDCs In Stage 3, CBR drops for a different reason, a change in SOCIETY: People choose to have fewer children Since more babies live from stage 2’s CDR drop, couples have fewer children Since fewer people work on farms and more in factories, fewer children is better Since urban homes are smaller, fewer children can fit. Many people are trading rural life for a smaller-scale urban life. This isn’t what I meant when I asked for a room with a view. I should have used birth control. THE EMPHASIS

7. In stage 4, the CBR and the CDR approach each other and then meet.Therefore, NIR approaches 0%And population stops growing. STAGE 4: LOW GROWTH This is called ZERO POPULATION GROWTH (ZPG): Both CBR and CDR are low and stable (often around the 10s) Countries meet REPLACEMENT FERTILITY RATE where births replace but do not exceed the number of deaths (TFR: 2.1)

8. Okay, hotshots… Quiz time. Which countries are in stage 4 of the Demographic Transition? Don’t Be Fooled: Not all countries with a TFR of 2.1 or below are stage 4 countries. Some have high CDRs Others have strict anti-natal policies Don’t Be Fooled: Not all countries with a TFR of 2.1 or below are stage 4 countries. Some have high CDRs Others have strict anti-natal policies

9. Countries enter stage 3 because of a change in SOCIETY. Countries also enter stage 4 because of a change in society: More women are educated and educated longer (delayed childbirth) More women pursue careers (delayed childbirth) Daycare is expensive (fewer children) Better access to birth control (fewer and delayed children) Increased wealth and leisure = recreation (delayed children) …Think of all those poor schmucks with kids! …heh, heh, heh, Morons. THE EMPHASIS

10. Possible Stage 5 Death Rates exceed Birth Rates Population begins irreversible decline THE BIG PICTURE The Demographic Transition is a model that predicts changes in a country’s CBR, CDR, NIR and Population as that country goes through changes like the industrial or medical revolution. All countries are in one of the four stages. THERE IS ALSO

11. Stages of the Demographic Transition affect a country’s population in a few of ways: 1.The overall number of people (POPULATION grows) 2.The structure of the population The Age Distribution The Sex Distribution THE EFFECTS

12. POPULATION PYRAMIDS

13. A way to depict a country’s population profile graphically Y-Axis indicates age X-Axis is divided into mirror image Males to left of splitFemales to right of split X-Axis indicates % of population Graphed data are AGE COHORTS… population divided into 5 year groups POPULATION PYRAMIDS

14. People aged 65 and older And those aged 14 and younger DEPENDENCY RATIO is the percentage of a population too old or too young to work. SEX RATIO is the number of males for every 100 females in a population. In general, slightly more males than females are born. But females live longer POPULATION PYRAMIDS are considered DEPENDENTS.

15. Stage 2 CountriesCape Verde Islands Stage 2 countries have a wider bottom 1/3 and a narrow top 1/3. POPULATION PYRAMIDS The birth rate has remained high, so the base is broad. Stage 2 countries have very high dependency ratios often near 50% Stage 2 countries often have 1/3 of population under age 14.

16. Stage 3 CountriesChile POPULATION PYRAMIDS Stage 3 countries begin to look more like a classic Christmas tree. As the birth rate begins to decline, the middle third of the pyramid begins to fatten. As people begin to live longer, the top third fattens, too.

17. Only 1/6 of the population in Stage 4 countries is 14 and under (it was 1/3 in stage 2) Stage 4 CountriesDenmark POPULATION PYRAMIDS Stage 4 Countries look more rectangular with the taper beginning in the upper 1/3 of the pyramid. People are living longer (top fattens) and having fewer children (bottom slims) Only 1/3 of the population in Stage 4 countries are dependents (it was ½ in stage 2)