Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Demographic transitionFrank Notestein (b. 1945)1. High growth potential2. Transitional growth3. Incipient declineSlide 15Slide 16Slide 17Slide 18AGEC/FNR 406 LECTURE 3702468101750 1800 1850 1900 1950 2000 2050 2100BillionsDevelopedDeveloping World Population 1750-2100Links between population andthe environment1. Total pollution = (pollution per person x population) - pollution control - assimilation 2. Total resource use = (rate of resource use - recycling rate) x populationAs population increases...1. Pollution will increase unless pollution control improves2. Resources will be depletedunless recycling increases and resource use becomes more efficientThomas Malthus (1766-1834) English demographer and economist Graduated from Cambridge in 1788 (age 22) Friend of Hume and Rousseau Major work (published anonymously in 1798): An essay on the principal of population as it affects the future improvement of society NOT a short essay (600 pages long!)Malthusian argumentReproductive capacity of humans puts continual pressure on the “means of subsistence”Human numbers increase by geometric progression.Subsistence increases on arithmetically.Land, unlike people, cannot breed.The Malthusian principleTimePop,foodFoodPopulationChecks on population1. War2. Seasons of sickness3. Epidemics4. Pestilence5. PlagueAnd the “ultimate” check:6. FamineWhat Malthus missed1. Birth control and voluntary limits on population growth (i.e. population growth less than geometric)2. Agricultural productivity (i.e. growth in food production greaterthan arithmetic)The Malthusian principle, revisitedTimePop,foodFoodPopulationFoodPopA pattern of steadily increasing population growth, followed by aperiod of slowing population growth(as experienced by industrialized countries).Generally indicated as an S-shaped curve for population through time.Demographic transitionFrank Notestein (b. 1945)Three stages of population growth1. High growth potential2. Transitional growth3. Incipient decline1231. High growth potentialPre-industrialBirth rate high (25-40/1000)Death rate highLife expectancy shortPopulation growth low but positiveWidespread misery2. Transitional growthEarly industrialBirth rate remains high or risesDeath rate low and fallingLife expectancy risesPopulation growth “explosive”Mortality declines before fertility dueto better health, nutrition, and sanitation3. Incipient declineIndustrialBirth rate drops due to desires to limit family sizeDeath rate low and stableLife expectancy highPopulation grows until birth rate = death rateCharacterized by higher levels of wealth and reduced need for large families for labor or insurance.Message: Birth rates=death rates, country has completed the demographic transitionMessage: Birth rates > death rates, country is still in stage 2 of the demographic transitionKey Points1. Malthusian view of population growing faster than food supply has not come to pass.2. Evidence in support of “demographictransition” is strong:(90% of Europe, 25% of Africa)3. Neo-Malthusian views generally correspond toconcerns over environmental quality andspeed of demographic transition.Message: Fertility rates respond to increases in per capita income, speeding the demographic