Demographic Transition
Total fertility rate (TFR) = average number of children that a woman will have in her reproductive years (0 - 5+) Most useful measure of fertility for projecting future populations. This is just review- but make sure you understand TFR!
in 1998, TFR = 2.9 (greater than 2.1) 1.6 in developed countries 3.3 in developing countries Quick Think: What factors make the TFR higher in developing countries?
Quick Think: Based on this, what parts of the world are growing the fastest? Why do you think that is?
1. 1.Average level of education and affluence 2. 2.Importance of children as a part of the labor force 3. 3.Urban areas (is there access to family planning) 4. 4.Cost of raising and educating children 5. 5.Education and employment opportunity for women 6. 6.Infant mortality rate 7. 7.Average age of marriage and 1st child 8. 8.Availability of pension system 9. 9.Availability of legal abortions Birth control/religion Focus: Take note of how these things may impact fertility rates!
Population increase is not necessarily due only to increased birth rate, but also decreased death rate Life expectancy 2. 2.Infant mortality rate = # of babies/1000/year Most important measure of quality of life since it is linked to so much of society!
Checkpoint: So as you can see, lots of different factors influence population size. Now, we will look at how we can show these changes in steps, known as the demographic transition…
What is the demographic transition? In your notes, be sure to sketch each stage of the transition and describe the
The demographic transition is a model, but has occurred in many countries. Many scientists believe it will not apply in all cases. Do we have enough resources for all countries to undergo this transition?
Why do countries continue to grow, even if the total fertility rate falls below the replacement level? Population momentum: a relatively large, younger generation still needs to pass through their child bearing years + life expectancy generally increases as a country develops Quick Think: What stage of the demographic transition is represented in each age structure diagram?