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Chapter 3: Population Key Issue 4: Why might the world face an overpopulation problem? Malthus Thomas Malthus (1766-1834) Consequences: Essay on the Principle of Population 1798 Population Growth vs Food Supply Population growing too fast for food supply Pop grows geometrically while population growths arithmetically Example: Today- 1 person, 1 unit of food 25 years- 2 people, 2 u.o.f. 50 years- 4 people, 3 u.o.f. 75 years- 8 people, 4 u.o.f Population growth would press against available resources Disease, famine, war would ensue Neo-Malthusians Two problems even worse than in Malthus’ time Malthus failed to anticipate that poor countries would have rapid pop growth Resource gap wider than Malthus assumed World pop is outstripping resources Not just food production Malthus’s Critics Unrealistically pessimistic Malthus based theory on idea that supply of resources is fixed, not expanding Larger pop can stimulate economic growth Malthus’s arithmetic – capitalism (Engels’ Theory) Too few people can retard the economy just as too many Resources should be shared equally Economic development Poverty, hunger, etc. caused by lack of economic development with unjust social and economic institutions NOT population growth More people = more power? Political leaders in Africa More pop = more men in army Reality Conditions last halfcentury do not support Malthus theory Food production has increased dramatically Green revolution Wheat production X2 Slowed recently? Declining Birth Rates Food production increased more than Malthus predicted Malthus’s model expected that the pop would quadruple but it didn’t Rate of Natural Increase is decreasing More deaths or less births Exception LDCs Reasons for declining birth rate Economic Development: lowering birth rates improve economic conditions women more likely to attend school increased knowledge of family planning better health care programs Distribution of Contraceptives World can’t wait for economic improvement LDC’s demand is greater than supply Still is occurring Bangladesh, Colombia, Morocco, Thailand Has not spread to Africa Reflects the status of women Contraceptives a religious issue and political issue India Became independent 1947 Began a population planning program in 1950’s Today sterilization is making a comeback Census in 1960’s reveals extreme growth During the 1970’s the Indian government began a policy of forced sterilization of any man with three or more children. 3.7 million were sterilized Public outcry and opposition • • Propaganda now encouraging “small” families India gendercide China’s One Child Policy • Forced abortion World Health Threats Epidemiologic transition: focuses on distinctive causes of death in each stage of the demographic transition Epidemiology: Branch of medical science concerned with the incidence, distribution, and control of diseases that affect large numbers of people Epidemiologic Transition Stage 1 & 2 Stage 1: Pestilence and famine Infectious and parasitic diseases were principal causes of human death Malthus called these “natural checks” Example: Stage 2: Receding Pandemics Black Plague Pandemic is a disease that occurs over a wide and affects a very high proportion of the population Industrial revolution helped slow spread of disease Not immediately Example: Cholera Black Plague Bubonic plague Worst stage 1 case From Kyrgyzstan brought by Tatar army Spread from urban areas to rural areas Western Europe 1348 Northern Europe 1349 Wiped out entire villages and families United States- 25 million died China – 13 million died Cholera Stage 2 Pandemic: disease occurs over a wide geographic area Poor people crowded into industrial cities ½ million in NYC died in 1832 1/8th population of Cairo 1831 Geographic Models the key to understanding Edwin Chadwick (1800-1890) Residents in poorer neighborhoods had higher incidences of Cholera Dr. John Snow (1813-1858) Mapped distribution of deaths in London Not a cause of sinful behavior Water pumps the cause Stages 3 & 4 Stage 3: Degenerative and human-created diseases characterized by a decrease in deaths from infectious deaths and chronic disorders associated with aging Cardiovascular disease cancer Decline in infectious diseases has been sharp in stage 3 countries Recently LDCs recently moved from stage 2 to stage 3 Effective vaccines Stage 4: delayed degenerative diseases Cardiovascular disease and cancer still linger but life expectancy extended Improved healthcare Improving behaviors as well Better diet Reduced use of tobacco, alcohol, and exercise Stage 5 ???? Stage of reemergence of infectious diseases and parasitic disease Old and new have emerged Three reasons: Evolution Poverty Microbes evolved, changed = resistant Example: Malaria TB in LDCs Long, expensive treatment Improved travel H1N1