Key Issue 2: Why Do Populations Rise & Fall in Particular Places? Chapter 2: Population Key Issue 2: Why Do Populations Rise & Fall in Particular Places?

AP Human Geography is not just another class… It is a matter of LIFE and DEATH!

Key Issue Overview Introduction Natural Increase Fertility Mortality Crude Birth Rate (CBR) Crude Death Rate (CDR) Natural Increase Rate (NIR) Doubling Time Fertility Total Fertility Rate (TFR) Mortality Infant Mortality Rate (IMR) Life Expectancy

Measuring Population Change Demographic Balancing Equation Population change = (Births -Deaths) +(Immigrants -Emigrants) Or using the common notation, it can be expressed: Pt -P0 = (B -D) + (I-E) Where: P0 is the initial population and Pt is the population after time t

Measuring Population Change Natural Increase In this chapter, we will just be looking at births and deaths. This is called the ‘Natural Increase’. We will bring migration into the equation in Chapter 3.

WORLD POPULATION GROWTH

WORLD POPULATION GROWTH

Natural Increase Rate (NIR) The term “natural” means that this rate does NOT include migration. Natural Increase Rate (NIR) Percentage by which a population grows in a year Only uses birth and death rates Immigration and emigration are excluded Doubling time Number of years needed to double a population

Crude Birth Rate (CBR) Total number of live births per year / 1,000 people in a society

Crude Death Rate (CDR) Total number of deaths per year / 1,000 people in a society

Natural Increase Rate Percentage by which a population grows in a year NIR = (CBR – CDR) / 10

Components of Population Growth Natural Increase About 82 million people are added to the population of the world annually. Rate of natural increase affects the doubling time– number of years needed to double the population, assuming a constant rate of natural increase. Twenty-First Century Rate (1.2 percent): 54 years Global population in 2100 would reach 24 billion. 1963 (2.2): 35 years Global population in 2010 would have been 10 billion instead of nearly 7 billion. More than 95 percent of the natural increase is clustered in developing countries.

Natural Increase Rate Example United States (2010): Population ≈ 308,745,538 Births ≈ 3,999,386 - CBR ≈ Deaths ≈ 2,437,163 - CDR ≈ CBR = #Births / (Total Population / 1000) CBR = 3,999,386 / (308,745,538 / 1000) CBR = 3,999,386 / 308,746 CBR = 13.0

Natural Increase Rate Example United States (2010): Population ≈ 308,745,538 Births ≈ 3,999,386 - CBR ≈ 13 Deaths ≈ 2,437,163 - CDR ≈ CDR = #Deaths / (Total Population / 1000) CDR = 2,437,163 / (308,745,538 / 1000) CDR = 2,437,163 / 308,746 CDR = 8

Natural Increase Rate Example United States (2010): Population ≈ 308,745,538 Births ≈ 3,999,386 - CBR ≈ 13 Deaths ≈ 2,437,163 - CDR ≈ 8 NIR = (CBR – CDR) / 10 NIR = (13 – 8) /10 NIR = 5/10 NIR = .5%

Doubling Times The doubling time is the number of years before a population will be twice as large as it is today.

Doubling Times The doubling time is the number of years before a population will be twice as large as it is today. World = 50 U.S = 138 MDCs = 143 LDCs = 40 Africa = 27 years Latin America = 38 years Asia = 46 years North America = 117 years Europe = decreasing!

Total Fertility Rate (TFR) Average number of children a woman will have throughout her childbearing years (ages 15-49) Behavior predictor

Palestinian Territories Total Fertility Rate the average number of children a women will have in her childbearing years (15-49 yrs. old). This rate varies from just over 1 (Japan, Italy) to around 7 (Niger, Mali). The U.S. rate is 2. The global average is 2.5 2.1 is generally regarded as the replacement rate (the rate at which a population neither grows nor shrinks) in the developed world. TFR exceeds 5 in sub-Saharan Africa, while 2 or less in nearly all European countries Palestinian Territories Total Fertility Rate 1975-1980 7.39 1980-1985 7.00 1985-1990 6.43 1990-1995 6.46 1995-2000 5.99 2000-2005 5.57 U.K. Total Fertility Rate 1975-1980 1.72 1980-1985 1.80 1985-1990 1.81 1990-1995 1.78 1995-2000 1.70 2000-2005 1.66 Africa Total Fertility Rate 1975-1980 6.60 1980-1985 6.45 1985-1990 6.11 1990-1995 5.67 1995-2000 5.26 2000-2005 4.97

Infant Mortality Rate (IMR) Annual number of deaths of infants under 1 year of age, compared with total live births IMR is 5 in developed countries and 80 in sub-Saharan Africa

Life expectancy Number of years a newborn infant can expect to live, assuming current mortality levels Health care access and wealth indicator

LDC (Least Developed Country) MDC (Most Developed Country) Compare the following demographic factors: LDC (Least Developed Country) MDC (Most Developed Country) Crude Birth Rate = high Crude Death Rate = low Infant Mortality Rate = high Total Fertility Rate =high Life Expectancy = low Natural Increase Rate = high Crude Birth Rate = low Crude Death Rate =low Infant Mortality Rate = low Total Fertility Rate = low Life Expectancy = high Natural Increase Rate = low

Population Pyramid

Population Pyramids = graphic device that represents a population’s age and sex composition. Pyramid describes diagram’s shape for many countries in 1800’s when was created.

Population Pyramid Overview The most important demographic characteristic of a population is its age-sex structure. Age-sex pyramids (also known as population pyramids) graphically display this information to improve understanding and ease comparison. Age-sex pyramids display the percentage or actual amount of a population broken down by gender and age. The five-year age increments on the y-axis allow the pyramid to vividly reflect long term trends in the birth and death rates but also reflect shorter term baby-booms, wars, and epidemics.

Population Pyramids The shape of a pyramid is primarily determined by the crude death rate in the community. Dependency ratio-the number of people who are too young or too old to work, compared to the number of people in their productive years. People who are 0-14 and 65-plus normally are classified as dependents. The “graying” of a population refers to the aging of a community. Population pyramids also foretell future problems from present population policies or practices. Ex. China’s population policies skewed in favor of males.

Dependency ratio Number of people who are too young or too old to work, compared to the number of people in their productive years Indicates financial burden on a society’s productive population Dependency Ratio = measure of # of dependents – old and young that each 100 people in productive years (15 – 64) © 2013 Pearson Education, Inc.

Sex Ratio The number of males per hundred females in the population is the sex ratio. In Europe and North America the ratio of men to women is about 95:100 In poorer countries the high mortality rate during childbirth partly explains the lower percentage of women.

There are three key types of population pyramids: Rapid Growth: This pyramid of the Philippines shows a triangle-shaped pyramid and reflects a high growth rate of about 2.1 percent annually.

There are three key types of population pyramids: Slow Growth: In the United States, the population is growing at a rate of about 1.7 percent annually. This growth rate is reflected in the more square-like structure of the pyramid. Note the lump in the pyramid between the ages of about 35 to 50.

In wealthy countries with very slow rate of population growth – population is nearly equally divided - so pyramids have Almost vertical sides. War can be reflected by showing depleted age cohorts and male – female disparities. The % of a country’s population in each age group strongly influences demand for goods and services within that national economy. Country with high % of young has high demand for educational facilities and health delivery services.

There are three key types of population pyramids: Negative Growth: Germany is experiencing a period of negative growth (-0.1%). As negative growth in a country continues, the population is reduced. A population can shrink due to a low birth rate and a stable death rate. Increased emigration may also be a contributor to a declining population.

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