IE270 1st Edition Lecture 12 Outline of Last Lecture II. In class film “The People Paradox”III. IndiaIV. JapanV. AmericaVI. AfricaOutline of Current Lecture II. Social change and population changeIII. UN population ProspectsIV. Key termsV. Primary theories of population theory VI. Malthusian theory VII. Ester BoserupVIII.Theory of demographic transitionIX. DTMX. Changes in FertilityXI. Population PyramidsXII. 4 stages to DMTCurrent LectureUN population prospects3 different assumptions about fertility—LOW, MEDIUM, HIGHKey Terms- Natural Population Rate of Change—The number of births minus the number of deaths in a population over time- Fertility rate—the number of births in a population. Often the number of births per 1000people over a year- Mortality (death) rate—number of deaths in a population over a given time. Often per 1000people over a year- Migration—The movement of people over a distance that causes them to change their place of residence and place of livelihood- Immigration—in migration- Emigration—out migrationPrimary theories of population theory1. Malthusian theory2. Boserup theory3. Theory of demographic transitionMalthusian Theory- Basic thesis was that growth of a population is constrained by the means of subsistence - Argued that human populations, in their natural state, will increase exponentially- While the food supply will increase arithmetically or remain fixed- Emphasizes the concept of social and ecological system’s carrying capacityEster Boserup- population is reaching the point when the food supply is reaching exhaustion. Malthus says, the extra people have to die. Boserup says that you just have to upgrade the productivity of the food supply. Under pressure of numbers, with more mouths to feed, people put more labour and more intense effort into feeding themselves, and find ways to get more food production out of the land. They cultivate the land more intensively, they addextra manure, extra fertiliser, extra water and improve their crops. They invent their way out of the Malthusian crisis. Indeed, the Malthusian trap may even drive the development of technology. As Chairman Mau maintained, each mouth comes with a pair of hands.- Argued that human beings have the capacity to alter their social organization and agricultural practices in order to produce more food which therefore permits the existence of very large populationsTheory of Demographic transitionKingsley Davis—proposed a theory of demographic transition in the 1940s that explained the dramatic decline in mortality and fertility rates observed during the past 200 yearsDavis noted that in pre-modern societies both fertility and mortality rates are highAs modernization occurs—mortality rates decline rapidly. However, fertility rates tend to declinelater, and usually at a slower rate. The result was what Davis coined the “POPULATION EXPLOSION”—a rapid increase in total populationDemographic transition model has 3 stages1) High birth and death rates2) High fertility rate, low death rate (population explosion)3) Low birth rate, low death rate (returns to equilibrium)Mortality rates can be decreased due to structural changes and do not require changes in personal behaviorFertility rates drop to changes in personal value, behavior, and public policyChanges in fertilityFertility declines due to personal and family decision that may be due to:- Changing economic conditions- Expectations of life expectancy for children (surviving 5th bday)- Public policyPopulation PyramidsShow gender and age segmentationsDivides population into age cohorts: usually 5yrs- 0-4 years- 5-9 years- 10-14years- Etc.4 stages to demographic transition model1) Expanding—high birth rate, rapid fall in each higher age group due to high death rate; short life expectancy2) Still expanding—High birth rate, fall in death rate with more people living in middle age; slightly longer life expectancy3) Stationary—Declining birth rate, low death rate, more people living to older ages4) Contracting—Low birth rate, low death rate. Higher dependency ratio; longer life