Chapter 3 Population Describe global population distribution Examine causes and consequences of population change To understand the Malthusian argument To describe demographic and economic characteristics of a population To understand the Demographic Transition Understanding economic migration

Population Explodes after the Industrial Revolution World population growth throughout history. For most of human existence, population levels were low and growth rates were zero. Only with the Industrial Revolution that created the modern age did growth rates begin to rise, leading to an exponential increase in the numbers of people.

The current rapid growth rate of the world population is a recent phenomenon. It took from the emergence of humankind until 1850 for the world population to reach 1 billion. The second billion was added in 80 years (1850–1930), the third billion was added in 30 years (1931–1960), the fourth in 16 years (1960–1976), the fifth in only 11 years (1977–1987), and the sixth in 12 years (1987–1999).

Population Density FIGURE 3.2

In 2010, there were approximately 6.9 billion people in the world. The diverse populations that inhabit the world are very unevenly distributed geographically.

Cartogram of Global Population FIGURE 3.3

FIGURE 3.4

Population Growth over Time and Space World population growth is slowing Still adding ca. 80 million per year Most in developing countries Some countries are losing population (Russia, E. Europe, coming in Japan) Forces affecting population change ∆P = BR – DR + I – O or ∆P = NGR +NMR

Malthusian Theory Assumed that human populations would continue to grow geometrically And assumed that food production would grow arithmetically, due to diminishing marginal returns (or less than arithmetically) arithmetic Output if there are diminishing returns Output Inputs

FIGURE 3.6

FIGURE 3.8

Malthus’ Expectations & Reality Failed to see impact of Industrial Revolution on Food production Failed to see the opening of new lands (especially in the new world) Failed to anticipate falling fertility rates Time scale on this diagram is not realistic

Neo-Malthusians: The Club of Rome and The Limits to Growth

Demographic Transition Theory Based on Western European & North American History

Stages in Demographic Transition Theory Stage 1: Preindustrial Society – high and unstable birth & death rates, population growth rate slow, importance of children, low life expectancy Stage 2: Early Industrial Society - high birth rates, falling death rate, high population growth Stage 3: Late Industrial Society – low death rate, falling birth rate, high population growth Stage 4: Post Industrial Society – low birth and death rates, low population growth

FIGURE 3.13

Geography of Birth Rates Strongly Correlated with level of economic development FIGURE 3.15

Percent of population under age 18 FIGURE 3.16

Geography of Death Rates Evidence of Demographic Transition? FIGURE 3.17 Compare scale with map of birth rates

Shifting Causes of Death Stage 1 – Poor Health Care Stage 2 – Lower infant mortality rates with better diet and public health measures (Figure 3.19) Stage 3 – similar to Stage 2 Stage 4 – Few deaths from infectious diseases, more from social malaise (Figures 3.22 and 3.23). Some countries below ZPG

Population Growth and Income FIGURE 3.24

The Slowing of Population Growth FIGURE 3.26

Issues similar to The Limits to Growth

Future Population Levels Fertility levels remain as they are now Fertility levels decline

Contrasts between Malthus and the Demographic Transition Fertility is socially constructed, not taken for granted Population does not grow uncontrollably, but rather stabilizes at a slow growth rate as birth and death rates fall However, absolute population growth is still large (ca. 80 million per annum) due to the large base (current 6+ billion) Total future population depends on fertility rate trends in less developed regions (Figure 3.29)

Criticisms of Demographic Transition Theory Based on Western societies (Europe, North America, Japan) Not inevitable that there will be a fall in fertility rates in less developed countries Even with dramatically lowered fertility rates We cannot predict the length of time it will take these countries to move from Stages 2 and 3 to Stage 4 (if they do)

Population Structure Age structure of population – an indicator of state of development Relationship between age structure and demands for public services (education, health care…..) Population pyramids as indicators of age and gender structure of populations – typically constructed around 5 year age cohorts

Rate of Natural Increase FIGURE 3.25

Cape Verde – high birth rates, low death rates, high natural increase

Chile – Declining Death Rate, declining rate of natural increase

Denmark – low birth and death rates, low rate of natural increase

Summary This chapter provides an overview of population trends over the long-run The Industrial Revolution – in different places at different points in history – has had powerful impacts on population levels Migration and natural increase vary in their regional importance over time The Malthusian vision of population growth has been largely replaced by demographic transition models Population movements are affected by differences in income levels, but also by environment and politics The gravity model can be used to model some population movements, and spatial interaction for many phenomena