Chapter 4: A Crowded Home
Ⅰ、Learning Objectives
By reading this chapter you should be able to:
1. Identify measures and concepts which explain demographics and population
growth or decline.
2. Identify the factors which affect rates of fertility and mortality.
3. Have an understanding of how the composition of a population changes over
time, the issues associated with both a primarily young or a primarily aging
population, and the measures which governments have taken to manage
population size and which have directly or indirectly affected population
composition.
4. Identify and have an understanding of the various explanations and models for
population growth or decline.
5. Identify and have an understanding of the various explanations for the relationship
between population and resources.
Ⅱ、Chapter Summary
Chapter 3 was a discussion of how human activities and the size of the human
population have a great impact on global ecosystems. This chapter is dedicated to
understanding the fundamentals of human population growth and decline, some of the
measures governments have taken to address these issues, and some of the social and
economic impacts of population growth and decline.
The two main factors which affect population growth, either globally or in a particular
region, are fertility and mortality. Fertility measures the human reproduction aspect of
population growth. Crude birth rate (CBR) is an actual measure of the number of live
births per 1,000 living people, whereas total fertility rate (TFR) is an estimate of the
average number of children a woman will have within a specific age range. As such,
demographers must be careful to consider which definition of fertility is considered when
using this measure. Mortality is the measure of death as a component of population
change. Mortality can be measured as the crude death rate (CDR)—the actual measure
of deaths in a given period per 1,000 people. Infant mortality rate is a measure of quality
of life and uses the CDR, but only counts infants. Mortality is also measured by life
expectancy.
Fertility varies spatially across the globe. This is because fertility is affected by
biological factors, such as sterility, reproductive behaviour, and diet; economic factors,
such as industrialization, urbanization, and the cultural changes which accompany
these; and cultural factors, such as contraceptive use, nuptiality, prevalence of abortion,
and women’s attitudes towards work and reproduction.
Mortality also varies spatially and is a general indicator of socio-economic status. As
status increases or decreases, so does life expectancy. One issue which has greatly
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affected mortality in sub-Saharan Africa, and is also beginning to affect mortality in Asia
and Russia, is the acquired immune deficiency syndrome (AIDS).
The rate of natural increase (RNI) is the difference between CBR and CDR. If RNI is
positive, then the population is growing, and if RNI is negative then the population is in
decline. RNI affects population doubling time: the larger the RNI the shorter the doubling
time, and the more quickly society must adjust to population growth. The balance of
fertility and mortality also affects the age and sex structure of a given region. An aging
population is associated with high costs related to health care, public spending, and
pensions—without a young working population, the tax base diminishes. A young
population is also associated with a labour force: the Marxist perspective is that large
populations produce a ‘reserve’ labour force, and hence adequate supply for workers in
the capitalist system. However, a large population is also related to the carrying capacity
of a region, that is, the regions capacity to support a population with resources.
Hence, population increase or decrease and composition is a concern for the
government. Various governments have had various pro-natal or anti-natal policies.
Most famous is China’s one child policy. However, this affected the sex ratio of a certain
age cohort in Chinese society, as male children were favoured.
Population projections are not always accurate. In the past, projections of growth
where grossly underestimated. Fertility and mortality rates are now measured more
accurately, and lie within narrower ranges. Population projections also elicit debate over
what factors affect population, and for what factors population size is important: in 1708,
Malthus predicted that population growth would be limited by resources, but due to
technology, populations continued to grow and use resources. Other theories to explain
population growth are the s-curve, Boserup theory, the demographic transition model,
and fertility transition. Marxist theory remains relevant to this debate as well.
Ⅲ、the key points of the text
The United Nations estimates that there will be 7.9 billion people by the year 2025, and
9.1 billion by 2050. Their ultimate estimate is that there will be a population of about 10 billion
people by 2200. The greatest increases of population have been recorded in areas that are
incapable of supporting increased numbers. Demography is the study of human population in
terms of its size, distribution, and composition.
The fundamental thing to understand before we can study issues associated with
population, be that growth, policies, or the effects of change in population structures, is that we
must learn the basic ways we can measure population. A key question that arises and is useful to
keep in mind is whether or not the world is overpopulated—this tends to be the most basic
question with regard to population studies in a global context. The spatial variations in
population growth and decline, at all scales, leads us to answers to that fundamental question,
which show how the two worlds (developing and developed) differ in demographic terms and
trends.
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1、Fertility and Mortality
The rates of fertility and mortality vary with time and location. Additionally, fertility and
mortality help highlight the differences in some policies, health related issues, and cultural
variations in attitudes towards birth and death. The two things which seem common to us all is
the fact of birth and death, but how these vary from place to place and region to region point to
great differences in those common human traits.
（1）Fertility Measures
CBR (Crude Birth Rate) is the total number of live births for every 1,000 people. It is called
crude because it is a proportion of the total population and not only of those who can give birth.
It is a factual measure. The world CBR in 2002 was 21.
CBR = number of live births in one year x 1,000
mid-year total population
CBR 
Total live births in a year
 1000
Averagetotal (midyear ) population in that year
B
 1000
P
GFR (General Fertility Rate) refers to the actual number of live births per 1,000 women in the
fecund age range of 15–49.
or : CBR 
GFR 
Total live births in a year
 1000
Total (midyear ) population of women aged 15  49 in that year
or : GFR 
B
F15 49
 1000
TFR (Total Fertility Rate) refers to the average number of children a woman will have in her
fecund years. It is a predictive measure. Usually a TFR of 2.1 to 2.5 is considered necessary to
maintain a stable population. Having more than 2 children (the decimal in the range for TFR) can
be attributed to some woman not having children, infant mortality, and the fact that some people
do not reach the age of fertility.
( 1 ) TFR 
49

x 15
n
fx 
7
f x ； ( 2 ) TFR   5 f ( i )
i 1
Bx
 1000（分年龄组生育率）
n Fx
n
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（2）Factors Affecting Fertility
Biological factors
Age is a key factor. Fecundity commences at age 15 and ends in the late 40s for females. Males
do not have a clear termination age.
Nutritional welfare also affects reproductive behaviour. Periods of famine are marked by reduced
fertility.
Diet is also a factor. Women with less body fat tend to be less fertile than others.
Economic factors
Increasing industrialization reduces fertility rates. As a result, modern societies focus on small
families and individual independence. Traditional societies value children as productive agents
and as security for the parents in their old age.
Cultural factors
The age at which females marry is considered important because if a woman marries late it may
reduce the number of fecund years.
The use of contraceptives affects fertility. The practice of contraception is closely related to
government attitudes and religion.
Abortion affects fertility and is subject to moral and religious condemnation. Religion, as seen
reflected in attitudes towards abortion and contraception, also affects fertility.
（3）Variations in Fertility
Spatial variations in fertility correspond to spatial variations in economic development. In 2002, the
more developed world had a CBR of 11 and a TFR of 1.6, while the less developed world had a CBR of 24
and a TFR of 3.1. This variation helps define why some countries are experiencing population decline
while others, regardless of economic status, continue to grow, albeit at a slower rate than in previous
decades. Fertility varies within any given country regardless of the development levels.
2、Mortality
（1）Mortality Measures
CDR (Crude Death Rate) is the total number of deaths in a given period (usually one year) for every
1,000 people. It is called crude as it does not relate the probability of dying to age.
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CDR = number of deaths in one year x 1,000
mid-year total population
CDR 
Total deaths in a year
 1000
Averagetotal (midyear ) population in that year
or : CBR 
D
 1000
P
number of infant deaths under one year old
 1000
number of births in that year
D
or : IMR  0  1000
B
IMR 
IMR (Infant Mortality Rate) is the number of deaths of infants below the age of 1 year per 1,000 live
births in a given year.
IMR = number of infant deaths under one year old x 1,000
number of births in that year
In 2002, the CDR for the world was 10, while the IMR was 54.
LE (Life Expectancy) is the average number of years to be lived from birth. In 2002, the LE for the world
was 67, with some countries in Africa barely reaching the mid-40s and others in the developed world
achieving LE of greater than 80 years. In 2000, the US Census Bureau estimated that Zambia had a LE of
just below 40, while Japan was just above 80.
（2）Factors Affecting Mortality
Mortality reflects socio-economic status. High LE figures are associated with a high quality living, good
working conditions, good nutrition, good sanitation, and accessible medical services.
（3）Variations in Mortality
The world pattern for the CDR reflects the general availability of minimal health care facilities
throughout the world. Additionally, access to clean and safe water and sustainable quality food
sources are key features of societies that have lower CDR, higher CBR and higher LE, as well as the
higher TFR mentioned earlier.
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Mortality measures may vary remarkably within countries. Low LE figures are found in the tropical
countries of Africa and in south and Southeast Asia, while high LE figures are common in Europe and
North America.
（4）Twenty-First Century Nightmare?
A disturbing mortality trend has been created because of the pandemic AIDS. The worst affected areas
are the less developed ones, particularly sub-Saharan Africa. The most vulnerable population, which is
also the most highly productive population, is the 15–49 age group.
Sub-Saharan Africa
An estimated 10 million children have lost their mothers to AIDS since 1991 in sub-Saharan Africa. A
2002 UN prediction anticipates 68 million Africans will die of AIDS by 2020 and that there will be 40
million AIDS orphans by 2010.
Poverty is the biggest single factor contributing to the spread of AIDS.
Russia, China, and India
The statistics for all three countries are unreliable, but it is believed that these countries will record
substantial increases in the number of people with AIDS.
 Increasing poverty, social freedom, and drug use have all increased the risk of HIV infection in
the Russian population.

In China the disease is primarily transmitted through heterosexual behaviour and the sale of
blood.

In India the majority of the epidemic is concentrated in major cities and is related to
heterosexual behaviour.
The future of AIDS
Attitudes towards AIDS are changing and governments are actively supporting safer sex practices. The
positive response from the more developed world has benefitted the worldwide fight against AIDS.
3、Natural Increase
RNI (Rate of Natural Increase) measures the rate of population growth. Low RNI figures are found in
Europe, while high RNI figures are concentrated in the west Asian Islamic world and tropical Africa.
RNI = CBR – CDR
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Regional Variations
Large populations grow faster than small ones, even if the large population has a low fertility rate. China
and India account for 38 per cent of the world’s population. Even a small increase would reflect a
significant increase in the total world population.
Ninety-nine per cent of the projected growth will occur in the less developed world. The greatest
amount of predicted growth between now and 2050 will take place in India and Africa.
Doubling Time is the number of years required to double the size of a population, assuming a constant
RNI. At the current 1.3 per cent growth rate, the world population would double in approximately 54
years.
4、Government Policies
To reduce mortality, governments must adopt measures to provide medical care and safe-working
conditions. Regardless of the levels of economic development, access to quality health care is not
equitable throughout the world. Access to clean and safe water and food is also essential to improving
life.
Pronatalist governments are generally found in Catholic- and Islam-dominated countries where the
politically dominant ethnic group is in fear of being overtaken by an ethnic minority or where a smaller
population would signify a loss of national identity. Where it is believed that the carrying capacity of a
region has been, or will soon be, exceeded, the most common current policies are antinatalist. Though
India was the first country to formally intervene to reduce its fertility, China has been more successful.
5、The Composition of a Population
Age and Sex Structure
The age and sex composition of a population can be represented with a population pyramid. Generally,
the pyramids differentiate males from females and group them into five-year categories. Three types of
pyramids are possible: pre-reproductive, reproductive, and post-reproductive.
6、Global Population Aging
The year 2000 is regarded as a watershed: persons under 14 were outnumbered by persons over 60.
Global aging is happening at an increasing pace. This means that the older population is growing faster
than the total population in many parts of the world.
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（1）Causes of Population Aging
Fertility levels have declined throughout the world. The TFR has decreased by half in the part 50 years;
therefore, the base of the population pyramid is narrow.
Declining mortality has resulted in an accompanying rise in life expectancy. Globally LE has increased by
about 20 per cent. This increase is attributable to improved health care and living conditions. There are
also regional differences in population aging related to trends in fertility decline and increasing LE in
other countries.
（2）Consequences of Population Aging




Consequences of population aging have led to the following:
Increased pressure on retirement, pension, and other social benefits
Rise in degenerative diseases associated with aging and substantial increased costs to health
care systems and insurance costs.
Decline in numbers of workers available to support the growing population of non-working
elderly
7、History of Population Growth
The growth of the human population has not been regular; there have been short but rapid growth
periods followed by longer intervals of slow growth.
The agricultural revolution, which spanned thousands of years, made hunting and gathering secondary
activities. The first region of high population density stretched from Greece to Iran and included Egypt.
Before the advent of agriculture, birth and death rates were high (about 35 to 55 per cent per 1,000
people) and LE was short (about 35 years). With the advent of agriculture, birth rates remained high
while death rates varied.
Since 1650 the world population has increased rapidly as a result of the industrial revolution.
（1）The Current Situation
The world population growth rate has fallen from 2.04 per cent per year in the late 1960s to 1.3 per cent
per year. Future population growth will not be globally uniform due to spatial variations in fertility.
（2）Population Projections
UN projections forecast a world population of 9.1 billion by 2050, assuming that CDR will be equal
throughout the world. Many scholars (catastrophists), however, predict that as the population exceeds
the carrying capacity, there will be a collapse of both population and economy. The cornucopians
believe that technological advances will make new resources available as old resources decline.
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8、Explaining Population Growth
（1）The S-Shaped Curve Model
The S-shaped curve model does not consider the effects of cultural and economic factors on a
population. In this model the growth process begins slowly and increases exponentially and then levels
out at a ceiling.
（2）Malthusian Theory
Malthus focused on overpopulation and the imbalance between population and food. He believed that
population growth was the root cause of poverty. According to his work, the different growth rates of
food supplies and population could be controlled if humans used preventive fertility checks. In reality,
however, only the positive checks would yield any concrete results.
（3）Marxist Theory
Marx believed that population growth must be regarded in conjunction with the existing mode of
production in a given society. He believed that the capitalist system was responsible for poverty and was
concerned about the surplus workers who were needed to keep wages low and profits high.
（4）Boserup Theory
Boserup believed that a growth in population must be followed by an intensification of agriculture in
order to feed the additional population. He argued that population growth has a positive effect because
it induces an increase in gross food output. However, it also means that food output per capita
decreases. This theory is not applicable to the developed world where technology is more important.
（5）The Demographic Transition
This factual model describes the changing levels of fertility, mortality, and natural increases over time in
the more developed world:
 The first stage is characterized by a high CBR and a high CDR. It also involves a low-income
agricultural economy.
 The second stage sees a decrease in CDR with the arrival of industrialization and medical
advances.
 The third stage is marked by a declining CBR reflecting voluntary decisions to reduce family size.
 The fourth stage is marked by an evenly balanced CBR and CDR.
Most of the developed world reached the fourth stage in the first half of the twentieth century, while
much of the less developed world reflects the third stage of the model.
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（6）The Fertility Transition
This model argues that reductions in fertility have been due to changes in cultural attitudes, willingness
to use modern contraceptive methods, and the ready availability of these products.
Large families are no longer popular due to the pressure on agricultural land and poor quality of urban
life. Females favour late marriages, small families, and increased spacing of births. The main reason for
declining fertility is the effective use of contraceptives.
（7）Evaluating the Available Explanations
Both the demographic and fertility transition models reflect the empiricist philosophy with their focus
on available facts. Both also offer explanations for the trends shown by the data.
The S-shaped curve model, the Malthusian theory, and the Boserup thesis reflect a positivist philosophy
relating cause and effect. Being hypothetical in nature, these theories have limited uses.
A humanistic approach is rarely used to analyze population growth. The fertility transition theory,
however, could use elements of this type of approach.
The Marxist philosophy regards population growth as a consequence of a society’s mode of production.
The Marxist theory is restricted to the period of early industrial capitalism.
（8）Alternative Explanations?
Feminist geography considers the question of gender inequality and the changing role of women. By this
view, the rise in status of women and control over reproductions choices has led to changes in
population dynamics. New and better explanations are required (irrespective of their philosophical
affiliations) to incorporate a detailed reality in various spatial, social, and temporal scales.
Ⅳ、Study Questions
1、Short Answer Questions
1. How did China’s one child policy skew the sex structure of China’s population and
why?
Answer: The 2000 census data showed a ratio of 118 males to 100 females in
China. In Chinese culture, as a son is responsible for the family after marriage,
and a daughter is only responsible for the family until marriage, sons are generally
favoured. When the one child policy was enacted, more female foetuses were
aborted, and infanticide—neglect and malnourishment towards female
babies—occurred.
2. What were some key problems with and criticisms of Malthus’ argument that
‘population growth will always create stress on the means of subsistence’?
Answer: First, the rates at which Malthus estimated the growth of food production
and population growth were criticized as there was not accurate scientific support
for his theory. History has shown that Malthus did not consider the widespread
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use of contraception or the use of agricultural technologies to increase crop
output, thereby changing the relationship between population and food resources.
3. Are population projections accurate? Explain why or why not.
Answer: In the past, populations have been very difficult to project. For example,
early projections estimated 2.4 billion people on the planet by 2100, another
prediction was of 3 billion people by 2000, whereas, in 2008 there were 6.8 billion
people. Population growth is difficult to predict because of the variety of factors
affecting populations differ depending on region, growth rates are uneven
spatially, and some factors, such as culture, are difficult to predict. Current
population projections give ranges of high, medium, and low to show the possible
population range.
4. Why is the spread of AIDS in various parts of the world being referred to as a
‘pandemic’?
Answer: The spread of AIDS has been relatively rapid in some parts of the world,
particularly sub-Saharan Africa, and is now rapidly spreading in Russia and parts
of Asia. In 1990, the rate of infection of the population in South Africa was 1 per
cent, but by 2006 it was 22 per cent. It is estimated that over 20 million people
have died of AIDS. In part, this is due to difficulty of intervention, conflicting
information concerning interventions, and lack of economic resources to provide
health services. Due to these very large impacts, the spread of AIDS is referred to
as a pandemic.
5. Why is fertility declining in the developed world?
Answer: Women have higher rates of university- or college-level education, have
become more integrated into the workforce, and are more likely to delay
childbirth—there is also a rising preference for single-child families. In Eastern
Germany, the rate of fertility is low enough that women are essentially not having
children; it is thought that this is related to the large cultural and economic shift
from communism to capitalism. A similar situation is occurring in other
post-communist countries, such as Poland, Bulgaria, Romania and Estonia, and
Russia. In Russia, it is thought that population decline is also related to economic
decline.
2、Research Questions
1. Whether or not population will encounter limits to resources has been debated
since Malthus perceived this issue. Is there merit to this argument today? Give
some examples of resource problems which enhance or dispel Malthus’
argument, making use of current facts and the arguments of other thinkers who
contributed to this debate.
2. What is the current thinking on fertility policies? Does government intervention
work as expected? Support your discussion with empirical examples.
3. What are some of the issues that arise when a population is aging? What
measures are governments taking when they encounter this issue and are they
successful?
4. What have been some of the responses from governments and other political or
religious bodies in addressing the AIDS pandemic? Where has there been
successes, and where could there be improvement in responses and why?
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5. Describe what is learned about women and gender issues from regions and
states which are experiencing declining fertility rates. How has this affected
academic study and thinking on government policy?
3、Links of Interest
United Nations Development Programme http://www.undp.org/
The World Bank http://web.worldbank.org
The CIA world factbook
https://www.cia.gov/library/publications/the-world-factbook/rankorder/2127rank.html
The Stephen Lewis Foundation http://www.stephenlewisfoundation.org/
United Nations Programme on Ageing http://www.un.org/esa/socdev/ageing/index.html
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