Population Size Factors (7-2) Jeff Roberge

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”)

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”)

Population  Population Graph  China most populous  Then India  And USA (Miller)

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”)

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)

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

Factors Affecting Death  Life Expectancy-ave. number of years expected to live  Nutrition  Disease  Medical availability  Health care for pregnant women

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

Case Studies  US Population  76 mil (1900) to 302 mil (2007)  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)

Case Studies  US immigration  Accepts twice the immigrants as all other countries added together  40% of growth  most immigrants from Europe  Now most from Latin America (53%), Asia (25%), Europe (14%)  Of Latin America: 67% are Mexicans (Vogel)

Case Studies  For immigration  Need it to keep culture and standing as place of better horizons  Needed for jobs most others reject, boost economy

Case Studies  Against- 60% of people against imm.  Mostly poor  Will help stop population growth  Better for ecological footprint with less people (“Immivasion”)

Conclusion  Population grows through increased births/decreased deaths and higher immigration than emigration  Population is mostly decided by total fertility rate

Works Cited “Below Replacement Fertility.” Singapore: The Last Ten Years. Aug Jan Da Vanzo, Julie and David Adamson. “Russia’s Demographic ‘Crisis’: How Real is it?” July Center for Russian and Eurasian Studies. 4 Jan “Immivasion.” Jan Miller, Jr., G. Tyler, and Scott Spoolman. Environmental Science: Problems, Concepts, and Solutions. 12th ed. US: Cengage Learning, “National Population Report.” Development Planning Unit of the British Virgin Islands. 21 Nov Jan “Texas Population Change ” 11 July Texas Department of State Health Services. 4 Jan Vogel, Richard D. “Mexican and Central American Labor: The Crux of the Immigration Issue in the U.S.” 20 June Jan