This preview shows page 1. Sign up to view the full content.
Unformatted text preview: Readings (Week 6)
Miller and Spoolman, Chapters 6 & 22 "Living with the Car: No Room, No Room," The Economist, December 6, 1997 Boyd, J. K. Caballero, and R. D. Simpson "Carving out Some Space: A Guide to Land Preservation Strategies," Resources, Summer 1999, pp. 10-13 - http:// www.rff.org/rff/documents/rff-resources-136.pdf Total Fertility Rates
Total Fertility Rates tend to be lower in developed countries Births per woman <2 2-2.9 3-3.9 4-4.9 5+ No Data World Total Fertility Rates Since 1950 Source: United Nations, World Population Prospects: The 2008 Revision http://esa.un.org/unpp/p2k0data.asp Total Fertility in the United States
Total fertility in the United States had a major increase during the "baby boom" (194664) & is now hovering around replacement level
4.0 Births per woman 3.5 3.0 2.5 2.0 1.5 1.0 0.5 1920 1930 1940 1950 1960 1970 Year 1980 1990 2000 2010 Population Age Structure
Age Structure refers to the proportion of the population in each age class: pre-reproductive (0 14 years) reproductive (15 44 years) post-reproductive (45 & up) Age Structure Diagrams
Rapidly growing populations have pyramidshaped age structures, with large numbers of pre-reproductive individuals Slower growing populations have a more even age distribution Age Structure Diagrams
Countries with zero population growth have nearly equal proportions of prereproductive & reproductive individuals Countries with negative growth have a lower proportion of prereproductive individuals World Age Structure Diagrams
Less Developed Regions Age More Developed Regions Male Female 80+ 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 17-19 10-16 5-9 0-4 Male Female 300 200 100 0 100 200 300 300 100 0 100 300 Population (millions) Population (millions) Source: United Nations, World Population Prospects: The 2002 Revision (medium scenario), 2003 Using Age Structure Diagrams to Predict Population
Developing countries are expected to continue to have a pyramid shape through the year 2025, although the age structure may become more evenly distributed Using Age Structure Diagrams to Predict Population
Developed countries are expected to have an increasingly even age distribution through the year 2025 Age Structure Diagrams of the United States
Population age structure of the U. S. continues to show a bulge as the baby boom generation ages The Aging of America 40 1945 41.9 workers As the U.S. population ages, the average worker is likely to face an increasing tax burden Number of workers supporting each Social Security beneficiary 30 20 1950 16.5 10 2075 1.9 1945 2000 Year 2050 2075 Immigration to the United States
Number of legal immigrants (thousands) 2,000 1,800 1,600 1,400 1,200 1,000 800 600 400 200 0 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000 2010 Year 1907 1914 New laws restrict immigration Great Depression Theory of Demographic Transition
A hypothesis that relates changes in population growth to stages in economic development 1) Pre-industrial Stage 2) Transitional Stage 3) Industrial Stage 4) Post-industrial Stage Theory of Demographic Transition Making Long-Term Population Projections Age Structure Diagrams Theory of Demographic Transition Computer Models Limits to Growth Model & Its Critique Why Control Population Growth?
(1) Global Perspective: the earth's "carrying capacity" is limited; population growth puts pressure on the global environment (e.g., greenhouse effect) (2) Local/Regional Perspective: in many areas of the world, population growth, poverty, and environmental degradation are linked (i.e., they feed on each other); these areas are trapped in a vicious circle (Dasgupta) In both cases, Common Property Resources are the basis of the problem Population, Poverty, and Local Environment
Example of Vicious Circle (Dasgupta): in sub-Saharan Africa, children help gather firewood and fetch water from distant areas as resources get depleted, longer distances need to be covered, which increases the usefulness of child labor and leads to high birth rates and population growth increased population puts even more pressure on the environment, people get poorer, and need even more children Common Property Resources and Population the full social cost of producing another child is not borne by the decision making household if common property resources are used to support the child in such cases, a household's decision to have another child may be rational from its own perspective, but could be harmful to society this type of institutional failure may justify government sponsored population control measures Lowering Birth & Fertility Rates identify important determinants of birth and fertility rates target the above factors with an appropriate policy package success is likely to depend on political will, choice of targeted factors, and design of policy instruments ...
View Full Document
- Spring '08