P OPULATION C HANGE Chapter 16, Section 1

M EASURING P OPULATION Population= # of people living in a given area at a time. Demography= the area of sociology that focuses on studying human populations. Three factors affecting a region’s population: Birthrate Death rate Rate of migration Help determine how populations change over time.

B IRTHRATE Birthrate= births within a population Live births/total population x 1,000 Gives the number of births per 1,000 individuals. Fertility vs. fecundity Fertility  # of births that actually occurred by women of childbearing age. Fecundity  measures those ABLE to have children Affected by various social, economic and health factors.

D EATH R ATE Mortality= number of deaths within a society. Death rate : Deaths/total population x 1,000 Death rates do not present an accurate picture of a country’s conditions… so, sociologists also use two other factors: infant mortality rate and life expectancy. Infant mortality rate= deaths among infants/total live births x 1,000 Life expectancy= average # of years a person can expect to live. There is a correlation between IMR and life expectancy. This helps determine the overall ‘health’ of a country.

M IGRATION R ATE Demographers also have to take into account the migration of individuals when determining a country’s population. Factors affecting migration: Push factors  religious or political persecution; famine; discrimination; overpopulation Pull factors  additional freedoms; economic opportunities; higher standards of living Migration rate= annual difference between in-migration and out-migration.

G ROWTH R ATE The three variables affect the size of a population. Rate at which a population is increasing= growth rate. Birthrate – death rate = growth rate. Doubling time= amount of time it takes the pop’n to double in size. Negative vs. positive growth rates… is the population growing or shrinking? Practice  calculating country growth rates

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G ROWTH R ATE – A NSWERS Brazil: (population is growing) Population grew 11% China: 5.26 (population is growing) Population grew 5% Denmark:.09 (population is growing) Population grew.09% Which population is growing the fastest?

S TUDYING A POPULATION To examine the composition of a country’s population, demographers (individuals who study population) look at population pyramids (also known as age-sex graphs). Breakdown of population male/female Percentage of the population each age group comprises Connect events to changes in population Make assessments about overall health Determine whether pop’n is growing or shrinking

E XPLAINING P OPULATION C HANGE Thomas Robert Malthus Malthusian Theory= population increases in a multiplicative fashion, whereas food supply only grows in an arithmetic progression. Basically… The population is growing too rapidly for the food supply to keep up. Malthus proposed ‘checks’ on population. Preventive checks  birth control, sexual self-control and delayed marriage and childbearing. Positive checks  war, disease and famine.

M ALTHUS ( CONT ’ D ) But, Malthus could not foresee two coming changes in society… 1) Advancement of agricultural techniques that allowed farmers to produce more on same amount of land 2) Birth control emerges as an effective and widely used method.

D EMOGRAPHIC T RANSITION T HEORY Population patterns are tied to a society’s level of technological development. Three stages of a society’s population. Stage 1 Preindustrial societies; high birthrate and death rate. I.e. central African societies Stage 2 Industrial societies; high birthrates and low death rates (due to improved conditions) Guatemala and other Latin American countries Stage 3 Industrial/post-industrial societies; low birthrates and death rates. North America and Europe

D EMOGRAPHIC T RANSITION T HEORY Stage 4 Low birthrate, low death rate, and increasing life expectancy. Approaching zero growth rate= pop’n not growing or shrinking. Stage 5 Low birthrate (less than in Stage 4), low death rate, and increasing life expectancy. Population shrinking

C ONTROLLING P OPULATION G ROWTH Current world’s population: 7,315,737,000* Current U.S. population: 324,827,684* * as of 10:40 am 5/18/2015 Two main strategies to control the world’s population- family planning and economic improvements

F AMILY P LANNING Strategy used to lower the birthrate; occurs when couples consciously decide to have a certain number of children. Helps reduce the number of unplanned pregnancies. Antinatalism= strict form of family planning involving official policies designed to discourage childbirth. In 1980, China adopted an incentive and sanction system. Government benefits for those who adhere to one child policy; large fines and penalties for those that do not.

E CONOMIC I MPROVEMENTS Better health, higher levels of income and access to education will help lower birthrates. However, many impoverished countries do not have the resources to provide this economic assistance. Demographers suggest evenly redistributing wealth within a nation to help reduce poverty. Encourage limits on family size once basic needs are met.