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Population Size Factors (7-2) Jeff Roberge
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Growth or Decline Populations can shrink or grow Based on population change Pop change=(B+I)-(D+E) Measured annually When (B+I) larger, pop increases (D+E) larger, pop decreases Population change= number of people added or taken from total population each year of a specified location (“Texas Population”)
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Growth or Decline Demographers study populations Use crude birth rate and Crude death rate Equal to number of deaths/births per 1000 people (“National Population”)
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Population Population Graph China most populous Then India And USA (Miller)
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Population Stabilization Have fewer babies to control population Fertility Rate-number of children born to a woman Two types: Replacement-level fertility rate and total fertility rate (TFR) Replacement= ave. number of children to replace the parents (usu. ~2.1) Still does not control pop. because children will begin to have children, carries on growth for 50 more years TFR= ave. number of children per woman (“Below Replacement”)
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Population Stabilization TFR has been declining 2007 Global ave=2.7 Developed countries 1.6 (from 2.5 in 1950) Developing countries 2.9 (from 6.5 in 1950) Still above replacement-level of 2.1 Therefore pop is not declining (Da Vanzo)
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Factors Affecting Birth Children as laborers Cost of children (education, Costs $250,000 to raise child to 18) Possibility to attain a pension Urban living vs. rural living Advancement opportunities for women Infant mortality rate-# of death per 1000 of children under 1 years old Age when married Ability to get abortions Birth control Religious beliefs Tradition and culture
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Factors Affecting Death Life Expectancy-ave. number of years expected to live Nutrition Disease Medical availability Health care for pregnant women
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Population Change Caused by: birth rates Fallen/risen death rates Emigration/Immigration Migration-moving of people into or out of a population Seek better jobs, improvement Conflicts, political strife, war, disasters, escape religious intoleration
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Case Studies US Population 76 mil (1900) to 302 mil (2007) 1946-1964 is the baby boom (79 mil added to population) Max TFR was 3.7, but now around replacement level 2007 TFR was 2.05; 1.6 in China USA still growing: 60% births, 40% immigration Expected to be: 419 mil by 2050 571 mil by 2100 (Miller)
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Case Studies US immigration Accepts twice the immigrants as all other countries added together 40% of growth 1820-1960- most immigrants from Europe Now most from Latin America (53%), Asia (25%), Europe (14%) Of Latin America: 67% are Mexicans (Vogel)
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Case Studies For immigration Need it to keep culture and standing as place of better horizons Needed for jobs most others reject, boost economy
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Case Studies Against- 60% of people against imm. Mostly poor Will help stop population growth Better for ecological footprint with less people (“Immivasion”)
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Conclusion Population grows through increased births/decreased deaths and higher immigration than emigration Population is mostly decided by total fertility rate
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Works Cited “Below Replacement Fertility.” Singapore: The Last Ten Years. Aug. 2001. 4 Jan. 2009. Da Vanzo, Julie and David Adamson. “Russia’s Demographic ‘Crisis’: How Real is it?” July 1997. Center for Russian and Eurasian Studies. 4 Jan. 2009. “Immivasion.” 2003. 4 Jan. 2009. Miller, Jr., G. Tyler, and Scott Spoolman. Environmental Science: Problems, Concepts, and Solutions. 12th ed. US: Cengage Learning, 2008. “National Population Report.” Development Planning Unit of the British Virgin Islands. 21 Nov. 2005. 4 Jan. 2009. “Texas Population Change 1900-2000.” 11 July 2005. Texas Department of State Health Services. 4 Jan. 2009. Vogel, Richard D. “Mexican and Central American Labor: The Crux of the Immigration Issue in the U.S.” 20 June 2006. 4 Jan. 2009.
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