1. Area IIIB: Population
Human Population

2. Measuring population change
World Population
Measuring population change
population increases through births and immigration and decreases through deaths and emigration
population change = (births + immigration) – (deaths + emigration)
crude birth rate: number of live births per 1,000 people in a population per year
crude death rate: number of deaths per 1,000 people in a population per year
annual rate of change (%) = 100 * (birth rate – death rate)/1000

3. World Population population change, continued
annual rate of change (%) = 100 * (birth rate – death rate)/1000
there are currently more births than deaths throughout the world (+ rate of change), but
the rate of the world’s population growth has decreased
annual population growth in 1963: 2.2%
annual population growth in 2004: 1.2%
but population base doubled from 3.2 to 6.4 billion during same time period

4. World Population population change, continued
annual rate of change, continued
difference between developed and developing countries
developed countries: 0.25%
developing countries: 1.46%
six fastest growing countries: India, China, Pakistan, Nigeria, Bangladesh, Indonesia
populations of China and India comprise 38% of world’s population
next most populated country is the U.S. with 4.6% of world’s population

5. World Population population change, continued
doubling time is one measure of population growth
rule of 70 is a quick way to calculate doubling time in years
divide 70 by growth rate (in %) to get doubling time in years
example: if the population grows by 1.2% in 2004, divide 70 by 1.2, which equals 58 years

6. Factors affecting population change
World Population
Factors affecting population change
fertility: number of births that occur to an individual woman in a population
replacement-level fertility is the number of children needed to replace their parents
total fertility rate (TFR) is the average number of children that a woman has during her fertile years
there are apt to be between 7.2–10.6 billion people by 2050, with 97% of this growth to be in developing countries

7. Factors affecting population, cont.
World Population
Factors affecting population, cont.
birth and fertility rates
1. importance of children to labor force
2. economic cost of raising and educating children
3. availability of private/public pension systems
4. access to family planning
5. educational and economic choices for women
6. infant mortality rate
7. marriage age of women
8. availability of abortion
9. availability of reliable birth control

8. Factors affecting population, cont.
World Population
Factors affecting population, cont.
death rates
1. food supplies, nutrition, clean water
2. medical advances, public health, improved sanitation and personal hygiene

9. United States population
World Population
United States population
baby-boom period: sharp rise in birth rate in U.S. from 1946–1964
at its peak, the TFR reached 3.7 children per woman
there has been a gradual decline since then
however, population growth of the U.S. is still greater than any other developed country
other developed countries expected to have declining populations after 2010
U.S. has a high per capita rate of resource use  large effect on environment

10. United States population, continued
World Population
United States population, continued
U.S. population grew by ~2.7 million people in 2004
55% from more births than deaths
45% from immigration
the high U.S. per capita resource rate use produces enormous environmental impact

11. United States population, continued
World Population
United States population, continued
immigration into the U.S.
arguments to limit:
aid in stabilizing population sooner
help reduce environmental impact of U.S.
arguments against limit:
U.S. has been the land of opportunity for the world’s poor
immigrants do work that Americans won’t do or handle jobs for which there are not enough trained natives
immigrants contribute to the economy and pay taxes

12. Measures of population health
World Population
Measures of population health
life expectancy: average number of years a newborn can expect to live
infant mortality rate: number of babies out of every 1,000 born who die before their first birthday
reflects level of nutrition and health care
best measure of a society’s quality of life
U.S. infant mortality rate is relatively high:
inadequate health care for poor women and for their babies (?)
drug addiction among pregnant women, and
a high birth rate among teenagers

13. World infant mortality rates

14. Population Age Structure
Age structure diagrams
major categories:
1. pre-reproductive ages span birth to 14 years of age
major determining factor in a country’s future population
30% of planet’s population in 2004
2. reproductive ages include 15 through 44
3. post-reproductive ages include 45 and up

15. Population Age Structure
Age structure changes
economic and social effects
example: baby boom generation in U.S.
1. can dominate the population’s demands for goods and services
2. influence elections, legislation and economic demand
3. retirement may create a shortage of workers

16. Population Age Structure
Age structure changes, continued
economic and social effects, continued
example: baby bust generation
1. fewer people to compete for education, jobs, and services
2. may result in increase in wages
3. may be more difficult to get job promotions because a larger “baby-boom” group will occupy most upper-level positions.
there is an echo-boom consisting of people born since 1977

17. Population Age Structure
Age structure changes, continued
reduced fertility and population decline can have long-term consequences, especially if decline is rapid
1. effects of gradual decline can usually be managed
2. reduced fertility can result in a sharp rise in proportion of older people, resulting in:
sharp rise in public services/cost for health
fewer working taxpayers, labor shortages
necessity to raise retirement age, raise taxes, cut retirement benefits, and increase legal immigration

18. Population Age Structure
Age structure changes, continued
reduced fertility, population decline, cont.
3. if population declines because of deaths, consequences are serious
a. deaths from disease disrupt a country’s social and economic structure
b. large numbers of people at a particular age are removed from the country’s future
1) life expectancy drops
2) in the case of AIDS, deaths are mostly young adults (important to work force)
3) a major goal is to reduce the spread of HIV through education and health care

19. Solutions: Influencing Population Size
Is a rising population sustainable?
more growth = more consumption
the world is already overpopulated
basic necessities of life are not provided for one out of six people today
declining health and environmental conditions will threaten the entire world
increased resource use affects environment through infectious disease, biodiversity loss, fisheries depletion, water scarcity, pollution, climate change
the quality of life on the planet and for all its people requires some limits on everyone

20. Solutions: Influencing Population Size
Demographic transition
demographic transition hypothesis: as countries become industrialized, first their death rates and then their birth rates decline in four stages
1. pre-industrial stage: high birth and death rates because living conditions are harsh
2. transitional state: food production rise and improvement in health care; death rates drop, and birth rates remain high

21. Solutions: Influencing Population Size
Demographic transition, continued
demographic transition hypothesis, cont.
3. industrial stage: birth rate begins to drop, and the death rate drops because of industrialization and medical advances; modernization is widespread
4. post-industrial stage: moves toward zero population growth (birth rate = death rate); population size will begin to slowly decrease

22. Solutions: Influencing Population Size
Demographic transition, continued
some countries run risk of getting caught in transitional state; economic conditions will not be available to sustain the population
there can be a shortage of skilled workers to sustain the country’s economy
there will not be capital and resources to support rapid developing economies
international debt takes much of a country’s resources
developed countries are not helping developing countries economically

23. Solutions: Influencing Population Size
Reducing the population
family planning can reduce number of births and abortions
provides information on birth spacing, birth control, and health care
has been responsible for at least 55% of the drop in TFRs in developing countries
services come through educational and clinical services
almost one-half of pregnancies in developing countries are unplanned and 26% end in abortion
contraceptive access is a problem

24. Solutions: Influencing Population Size
Reducing the population, continued
family planning, continued
family planning success can be improved:
target programs to teenagers and unmarried, sexually active women
develop programs for educating men about their responsibilities for the children they father (largely cultural?)
provide more effective means of birth control for men
advocate that pro-choice and pro-life groups join to reduce unplanned birth and abortions

25. Solutions: Influencing Population Size
Reducing the population, continued
empower women by providing education, paying jobs, and supporting their human rights
women work two-thirds of all the hours worked, but receive 10% of the world’s income
empowering women with these things would:
slow population growth
promote human rights
reduce poverty
slow environmental degradation

26. Case Studies: India and China
overpopulation ills of poverty, malnutrition, and environmental problems abound
almost half of the labor force is unemployed
half the cropland is degraded due to soil erosion
two-thirds of the water is seriously polluted
efforts to limit population have not been especially successful because:
poor couples believe they need several children for work and care
strong preference for male children

27. Case Studies: India and China
China has controlled population growth by a strongly enforced government program
between 1972 and 2004, China’s birthrate was cut in half
couples with one child are rewarded with extra food, larger pensions, better housing, bonuses, free school tuition, and preferential employment treatment for the child
83% of married women use modern contraception, provided free by the government

28. Case Studies: India and China
China, continued
China’s population has an enormous environmental impact that may affect its production of food
the health clinics that used to provide basic health care for rural farm populations collapsed in the 1980s; now 9 out of 10 rural Chinese have no health insurance or social safety net

29. Cutting Global Population Growth
1994 U.N. Conference on Population and Development
goal: stabilize world population at 7.8 billion people by 2050
provide universal access to family planning services and reproductive health care
improve health care for infants, children, and pregnant women
develop/implement national population policies
improve status of women/expand education and job opportunities for young women
increase the involvement of men in child-rearing responsibilities and family planning

30. Cutting Global Population Growth
1994 U.N. Conference on Population and Development, continued
world population stabilization, continued
sharply reduce poverty
reduce unsustainable patterns of production and consumption
experience of Japan, Thailand, S. Korea, Taiwan, Iran, China indicates goals can be achieved through a combination of family planning, poverty reduction, and elevation of the status of women