Chapter 16, Section 1

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Chapter 16, Section 1

• The Dynamics of Demography

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The Changing Population

• Sociologists study population because it affects
  social structure
• Look for patterns that will help them understand
  and predict how groups of people will behave
• A population is a group of people living in a
  particular place at a specified time
• Demography the scientific study of population

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The Changing Population

• Demographers look at many factors
• Number of people (size)
• How and where they are located (distribution)
• What groups make up the population (composition)
• Ages represented in the population (age structure)

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The Changing Population

• Demographers analyze three processes
• Birth (fertility)
• Death (mortality)
• Movement from one place to another (migration)

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Fertility

• Fertility measures the actual number of children
  born to a woman or to a population of women
• Fecundity is the potential number of children
  that could be born if every woman reproduced as
  often as biology allowed
• Fertility rates are much lower than fecundity
  rates

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Fertility

• The crude birth rate is the annual number of live
  births per one thousand members of a population
• Varies from one country to another
• US 15/1000
• To calculate crude birth rate
• ( live births/total population) 1000

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Fertility

• Crude birth rate is approximate because it is
  based on the entire population rather than just
  women of child-bearing age
• Fertility rate (annual number of live births per
  one thousand women aged 15 44) is also used by
  demographers

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Fertility

• Birth rate is influenced by health and social
  factors
• Widespread disease causes the birth rate to
  decline
• Social factors include average age at marriage,
  level of economic development, educational status
  of women, etc.
• US birth rate has shown a steady decline

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Mortality

• Mortality refers to death
• Sociologists look at
• Life span the most advanced age to which humans
  can survive
• Life expectancy the average number of years
  that persons in a given population born at a
  particular time can expect to live
• World life expectancy is 67 years

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Mortality

• The crude death rate is figured by dividing the
  annual number of deaths by the total population
  and multiplying by 1000
• Demographers are interested in death rates for
  specific groups
• Age-specific death rates measure the number of
  deaths per thousand persons in a specific age
  group

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Mortality

• Infant mortality rate is considered a good
  indicator of the health status of any group

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Migration

• Migration refers to the movement of people from
  one geographic area to another
• Can occur within a country or between countries
• Gross migration rate is the number of persons per
  one thousand members of a population who enter or
  leave a geographic area in a given year

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Migration

• Net migration rate is the annual increase or
  decrease per one thousand members of a population
  resulting from movement into and out of the
  population
• It is possible to have a negative net migration
  rate showing more people overall leaving an area
  than entering it

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Migration

• US Census Bureau reports migration rates only of
  legal immigrants
• The issue of illegal immigration became a major
  concern in the 1970s and remains so today

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Assignment