1. Chapter Two
Population 1

2. Why Is Global Population Increasing?
Key Issue 2:
Why Is Global Population Increasing?
Components of Population Growth
Population Structure 2

3. World Population Through History
TCL_11e_Figure_02_08_L 3

4. World Population Growth
Title:
World population growth, 1950—2005.
Caption:
The percentage by which the population grew (that is, the natural increase rate [NIR]) declined during the late twentieth century from its historic peak in the early 1960s, but the number of people added each year did not decline very much, because with world population increasing from 2.5 to more than 6 billion people during the period, the percentage was applied to an ever larger base.
Fig. 2-9: The NIR declined from its historic peak in the 1960s, but the number of people added each year has not declined very much because with world population increasing from 2.5 billion to more than 7 billion people during the period, the percentage has been applied to an ever larger base. 4

5. Measuring Population
Measure population change done through three measures
Crude Birth Rate (CBR) {Natality Rate} is the total number of live births in a year for every 1,000 people alive in the population
Crude Death Rate (CDR) {Mortality Rate} is the total number of deaths in a year for every 1,000 people
Natural Increase Rate (NIR) is the percentage by which a population grows/declines in a year
NIR = CBR – CDR (then convert to percentage)
Represents country’s growth rate excluding migration
NIR is lower today (1.2%) than in the past
Peak in 1963 of 2.2
** Crude focuses on society as a whole rather than a refined look at particular individual and groups
→ Crude does not take into consideration all factors
Crude Birth Rate
Crude birth rate influenced by age and sex structure of population, but also by customs and family size expectations and its adopted population policies
30 or above per 1000 considered high
Typically found in Africa, western and southern Asia, and Latin America where population is usually rural and agriculture
18 or lower per 1000 considered low
Typically characteristic of industrialized, urbanized countries
Russia, Anglo America, Japan, Australia, and New Zealand have low rates
Between 18 and 30 called transitional birth rates
Usually developing and newly industrialized
CBR far outpacing CDR in LDCs
world population growing fast
LDCs – tend to lack adequate birth control often due to low income religious intolerance, lack of social status, inadequate education, or poor transportation
Crude Death Rate
Highest rates (over 20 per 1000) found in less developed countries of Africa, Asia, and Latin America
Lowest rates (less than 10 per 1000) found with developed states of Europe and Anglo America
Natural Increase Rate
Very small changes in the NIR dramatically affect the size of the population, because the base population from which we derive the percentage is so high
NIR of 1.2 percent means increase in global population of 80 million – drop that to 1.0% and global population increases 66 million – increase to 2.0% and world population would increase by 132 million 5 5

6. Crude Birth Rates Title: Crude birth rate (CBR). Caption:
The crude birth rate is the total number of live births in a year for every 1,000 people alive in the society. The global distribution of crude birth rates parallels that of natural increase rates. Again, the highest crude birth rates are found in sub-Saharan Africa and the Middle East, whereas the lowest are in Europe.
Fig. 2-8: The crude birth rate (CBR) is the total number of births in a country per population per year.
NOTE: The lowest rates are in Europe, and the highest rates are in Africa and several Asian countries. → Why? 6

7. Crude Death Rates Title: Crude death rate (CDR). Caption:
Crude death rate is the total number of deaths in a year for every 1,000 people alive in the society. The global pattern of crude death rates varies from those for the other demographic variables already mapped in this chapter. First, although Europe has the lowest natural increase, crude birth, and infant mortality rates, it has relatively high crude death rates. Second, the variance between the highest and lowest crude death rates is much lower than was the case for the crude birth rates. The concept of the demographic transition helps to explain the distinctive distribution of 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.
NOTE: Because wealthy countries are in a late stage of the Demographic Transition, they often have a higher CDR than poorer countries. 7

8. Crude Death Rates
Identify trends that have taken place in regards to the regional maternal mortality ratios

9. Natural Increase Rates
Title:
Natural increase rate (NIR).
Caption:
The natural increase rate is the percentage by which the population of a country grows in a year. The world average is currently about 1.5 percent. The countries with the highest natural increase rates are concentrated in Africa and Southwest Asia.
Fig. 2-7: The natural increase rate (NIR) is the percentage growth or decline in the population of a country per year (not including net migration).
NOTE: Countries in Africa and Southwest Asia have the highest current rates, while Russia and some European countries have negative rates. → Why? 9

10. Natural Increase Rates
Make geographic connections in relation to the
various levels of natural increase

11. Natural Increase Rates: Observations
Number of people added each year has dropped slower than the NIR because the population base is much higher now
Small changes in the NIR dramatically affect size of population * Base population is so high
Virtually 100 percent of natural increase is clustered in LDCs
2/3 of world’s population growth in last decade has been in Asia
* Other 1/3 in sub-Saharan Africa, Latin America, & the Middle East
Most of world’s additional people live in countries least able to maintain them!! 11

12. Factors That Influence the NIR
Economic Development
Education
Gender Empowerment
Healthcare
Cultural Traditions
Public Policy

13. Doubling Time
Doubling Time is the number of years needed to double a population, assuming a constant rate of natural increase
** Formula is dividing 70 by the Rate of Natural Increase
Doubling Time – At rate of 1.2% per year – world population would double in 54 years. When NIR was 2.2% - doubling time was 35 years 13

14. Fertility
Total Fertility Rate (TFR) is the average number of children a woman will have throughout her childbearing years
Roughly 15-49
Used to measure number of births in a society
TFR varies between MDCs and LDCs
Population requires a TFR of 2.1 in order to sufficiently replace the present population
Known as Replacement Rate

15. Total Fertility Rate
Fig. 2-12: The Total Fertility Rate (TFR) is the number of children an average woman in a society will have through her childbearing years.
NOTE: The lowest rates are in Europe, and the highest are in Africa and parts of the Middle East. → Why?

16. Total Fertility Rates
Total Fertility Rates
Does not take into consideration immigration and emigration
Today, the pace of world population growth is slowing. Where have Total Fertility Rates (TFRs) fallen below replacement level and why? 16

17. Total Fertility Declines
Differential Fertility Rate Declines
Fertility has declined most rapidly in Latin America and Asia and much more slowly in sub-Saharan Africa
In more than 20 developing countries, the 2006 fertility rate was below the replacement level, as it was for developed countries as a group.
Europe was far below with a 2006 TRF of 1.4; the U.S., however, with a TRF of 2.0 was nearly at the replacement level of 2.1 17

18. Population Pyramids - Age Structure
Displays a country’s population by age and gender on a bar graph
Important to study as population in a country is influenced by the percentage of the population in each age group and the distribution of males and females
Length of bar represents percentage of total population in that group
Typically, males are shown on the left and females on the right of population pyramid
Population pyramids used by demographers to assess needs and issues of the present/future
Can explain (to some extent) the population history of a country
Can convey the demographic situation of a country
Normally shows the percentage of the total population in 5-year age groups with the youngest group (0-4) at the base of the pyramid and the oldest group at the top
Typically, males are shown on the left and females on the right of the pyramid 18

19. Population Pyramids - Age Structure
Shape of pyramid determined by the CBR
Examine shape of pyramid by stage in demographic transition
Shape of the population pyramid affected by many factors
Health care, impact of war, availability of birth control, cultural values, and level of economic development
Country in stage 2 of demographic transition would have a wider base – shaped like a pyramid
Country in stage 4 of demographic transition would have a wider top shaped more rectangular
Country in stage 2 of demographic transition would have wider base – shaped like a pyramid
Country in stage 4 of demographic transition would have wider top – possibly more like a rectangle and a pyramid

20. Population Pyramids - Age Structure
Sex Ratio
Sex Ratio – number of males per hundred females in the population
Generally, more males than females are born, but males have higher death rates
Europe and North America 95:100
Rest of world ration is 102:100
Poor countries – higher mortality rate during childbirth explains lower percentage of women
Age Distribution
Higher population of elderly in later stages of demographic transition
Older people benefit from improved medical care and higher incomes
Larger percentage of elderly puts strain on the governments to meet needs of “greying” population
1/4 of government expenditures in U.S., Canada, and Japan go to programs for older population

21. Population Pyramids - Dependency Ratio
Dependency Ratio – number of people who are too young or too old to work, compared to the number of people in their productive years
Larger percentage of dependents leads to increased financial burden on those trying to support
Three age groups used for comparison
0 to to and older
0 to 14 and 65 and older are considered dependents
1/2 of people in stage 2 are dependents, while only 1/3 of people in stage 4 are dependents
Dependency ratio is 1:1 in stage 2 and 1:2 in stage 4
Large percentage (15%) of children in sub-Saharan Africa and other stage 2 countries strains ability of poor countries to provide needed services
Schools, hospitals, and day-care centers

22. Percent of Population under 15
Fig. 2-15: About one-third of world population is under 15, but the percentage by country varies from over 40% in most of Africa and some Asian countries, to under 20% in much of Europe.

23. Types of Population Pyramids
EXPANSIVE
population pyramids show larger numbers or percentages of the population in the younger age groups, usually with each age group smaller in size or proportion than the one born before it. These types of pyramids are usually found in populations with very large fertility rates and lower than average life expectancies. The age-sex distributions of Latin American and many Third World countries would probably display expansive population pyramids.
CONSTRICTIVE
population pyramids display lower numbers or percentages of younger people. The age-sex distributions of the United States falls into this type of pyramid.
STATIONARY or near-stationary
population pyramids display somewhat equal numbers or percentages for almost all age groups. Of course, smaller figures are still to be expected at the oldest age groups. The age-sex distributions of some European countries, especially Scandinavian ones, will tend to fall into this category.

24. Types of Population Pyramids

25. Population Pyramids in U.S. cities
Discuss the shapes of each population pyramid.
Lawrence, Kansas
Naples, Florida
Laredo, Texas
Population pyramids DO NOT have to be used on only a national level
Used to describe cities or even neighborhoods
Using this information allows governments to develop policies and allocate resources to meet the current and future needs of the population 25

26. Population Pyramids
For poorer countries, the chart is shaped like a pyramid
Infant mortality rates are high, life expectancy is shorter
LDCs have wider base, because the majority of the population is under the age of 15 – few elderly people due to lack of sanitation and medical care

27. Population Pyramids
For wealthier countries, the chart is shaped like a lopsided vase (columnar)
Population is aging, TFRs are declining

28. Evolution of Baby Boomers Cohort of people born between 1946 and 1964
Graphs show the progression of “boomers” (cohort born between 1946 and 1964)
Associated with changing American lifestyles and expenditure patterns
1970 more $$ and effort on childhood and young adult interests
2000 many are workers – wants and spending patterns shape the national culture and economy
2030 – needs for retirement facilities and old-age care will be central concern
Analyze the political, economic, and social impact/changes that would occur in a society as the density of Baby Boomers changes on an age/sex structure.