Population and Malthus

Demographic Transition

Stage 1 Stage 2 Stage 3 Stage 4

Time

Naturalincrease

Birth rate

Death rate

Note: Natural increase is produced from the excess of births over deaths.

4 stages based on level of IndustrializationLevel one the least industrialized to Level 4 the most industrialized

• greater industrialization – lower birth rate and higher mortality rate until natural increase or growth rate is either zero or negative numbers

• You can tell the level of industrialization by looking at population pyramids

Demographic Transition in Sweden

and Mexico

Sources: B.R. Mitchell, European Historical Statistics 1750-1970 (1976): table B6; Council of Europe, Recent Demographic Developments in Europe 2001 (2001): tables T3.1 and T4.1; CELADE, Boletin demografico 69 (2002): tables 4 and 7; Francisco Alba-Hernandez, La poblacion de Mexico (1976): 14; and UN Population Division, World Population Prospects: The 2002 Revision (2003): 326.

0

10

20

30

40

50

60

1775 1800 1825 1850 1875 1900 1925 1950 1975 2000

SwedenBirth Rate

Death Rate

MexicoBirth Rate

Death Rate

Births/Deaths per 1,000

1750

Law of 70• The unprecedented

population growth of modern times heightens interest in the notion of doubling time.

• Calculation of population doubling time is facilitated by the Law of 70

• If a population is growing at a constant rate of 1% per year, it can be expected to double approximately every 70 years

• -- if the rate of growth is 2%, then the expected doubling time is 70/2 or 35 years.

Malthus (1766-1834)• Population issues of fertility and mortality or births and

deaths• In his Essay on the Principle of Population, initially

published in 1798, Malthus postulated that population tended to grow geometrically while the means of subsistence (food) grew only arithmetically– Mathusian Trap – Gap (gap cannot persist indefinitely)

• arithmetic growth (food):1, 2, 3, 4, 5, 6, 7, 8, 9, 10…• geometric growth (population):1, 2, 4, 8, 16, 32, 64, 128, 256, 512…• Malthus argued that the difference between geometric and arithmetic

growth caused a tension between the growth of population and that of the means of subsistence

Food & Population, 1950-2000Malthus vs.

Actual Trends

Fig. 2-20: Malthus predicted population would grow faster than food production, but food production actually expanded faster than population in the 2nd half of the 20th century.

Fallacies in theory • War, hunger, disease, vice, morality served as a positive

check on population growth• Preventive checks: birth control through

– later age at marriage– abstinence from sex outside marriage. – Malthus opposed artificial methods of birth control on

moral grounds.• Viewed contraception as a vice

• Contrary to Malthus’s prediction, mortality (death rate) has not yet risen to curb world population growth– 1 billion people in 1800 - 6 billion end of 20th century

• Malthus did not forsee the population explosion• He did not recognize the force of the Industrial Revolution

which produced exponential growth in the means of subsistence

Malthus and Marx Today

• Neo-Malthusians - Believe we are approaching, or have already surpassed, the earth’s carrying capacity.– We should make over-population issues our first

priority.• Neo-Marxists - Believe eliminating oppression and

poverty through social justice is the only solution to the population problem.– Wealth and resource distribution must be addressed.

The demographic Transition

The Demographic Transition in Developed and Developing

Countries

The model itself

Population pyramids

Population Pyramids

• Graphic representation of a population

• Shows age-sex composition

• Broad base = high fertility and mortality

• Narrow base = low fertility and mortality

Age Structure Diagrams

CAMEROON

USA

JAPAN

2000 2050

Female Labor Force Participation Rates Vary Widely around the World…

Population growth by country

Over Time, Geometric Growth Overtakes Arithmetic Growth

The Demographic Transition

Modernization Theory

• Macro-level theory that sees human actors as being buffeted by changing social institutions.– Individuals did not deliberately lower their risk of

death to precipitate the modern decline in mortality. – Society wide increases in income and improved public

health infrastructure brought about this change.

The Demographic Transition: Impact on Society

World Population Growth1950 - 2005

Fig. 2-6: Total world population increased from 2.5 to over 6 billion in slightly over 50 years. The natural increase rate peaked in the early 1960s and has declined since, but the number of people added each year did not peak until 1990.

Life Expectancy at birth

Fig. 2-11: Life expectancy at birth is the average number of years a newborn infant can expect to live. The highest life expectancies are generally in the wealthiest countries, and the lowest in the poorest countries.

Crude Death Rates

Fig. 2-12: The crude death rate (CDR) is the total number of deaths in a country per 1000 population per year. Because wealthy countries are in a late stage of the Demographic Transition, they often have a higher CDR than poorer countries.

Population Pyramids in U.S. cities

Fig. 2-16: Population pyramids can vary greatly with different fertility rates (Laredo vs. Honolulu), or among military bases (Unalaska), college towns (Lawrence), and retirement communities (Naples).

HIV/AIDS Prevalence Rates, 2005

Fig. 2-26: The highest HIV infection rates are in sub-Saharan Africa. India and China have large numbers of cases, but lower infection rates at present.

Human Population History

Estimated Human Population Growth

Life Expectancy

Table 4.2

What do population

statistics tell us about the development of a country?

Population and development

Not like the brazen giant of Greek fame, With conquering limbs astride from land to land;

Here at our sea-washed, sunset gates shall stand A mighty woman with a torch, whose flame Is the imprisoned lightning, and her name Mother of Exiles. From her beacon-hand

Glows world-wide welcome; her mild eyes command The air-bridged harbor that twin cities frame.

"Keep ancient lands, your storied pomp!" cries she With silent lips. "Give me your tired, your poor, Your huddled masses yearning to breathe free,

The wretched refuse of your teeming shore. Send these, the homeless, tempest-tost to me,

I lift my lamp beside the golden door!"