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Demography and Aging. What is “demography”?. Demography is the study of populations Counting and describing people Age, sex, income, marital status… Demographers calculate life expectancy birth and fertility rates average age at marriage…. Three basic processes affect population.
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What is “demography”? • Demography is the study of populations • Counting and describing people • Age, sex, income, marital status… • Demographers calculate • life expectancy • birth and fertility rates • average age at marriage…
Three basic processes affect population • Fertility • Mortality • Migration • Many factors affect these processes • Economic development, technology, religious and cultural values…
“Population aging” • 1. How do we measure this?
Indicators of population aging • Greater numbers of older people • Higher median age • A higher percentage of our population is “old” • In 1900, 4% of US population was 65+ • In 1996, just under 13%
2. What was the U.S. “baby boom” and when did it take place? • (and why do we care?!)
3. Which age group in the U.S. population is growing fastest?
What is causing this shift in age? • Increasing life expectancy • =changes in mortality • Declining birth rates • =changes in fertility • 4. Which of these is most important?
Fertility rates, 1950 and 2005 • Africa: 6.7 -> 5.1 • Asia: 5.9 -> 2.5 • Latin American / Caribbean: 5.9 -> 2.6 • North America: 3.5 -> 2.0 • Europe: 2.7 -> 1.4
6. Gender distribution • Are the majority of U.S. older adults men or women? Why?
Population pyramids • Also known as “age-sex pyramid” or age structure diagram • Shows how the “shape” of population changes • Often from pyramid (more younger people at the bottom, few old people) to rectangle (more equal distribution between ages)
Want to see more? • http://www.census.gov/ipc/www/idb/informationGateway.php
Uneven geographic distribution • Differences in fertility, mortality, and migration create different population characteristics in different areas • Differences between countries • Differences within countries • Which places in the U.S. are “old”? • Which places are “young”? • What difference does that make??
Interactive census tools… • http://www.census.gov/
Other demographic trends… • Increasing diversity • Increasing levels of education • Changes in families
Changes in families… • …affect who is available to take care of an older person. • Smaller families • Marriages and births at later ages • Increased likelihood of divorce • More blended families • …and the living arrangements of older people.
7. Who helps us when we are old? • Dependency ratios • Old age dependency ratio - % of population 65+ compared to % of population 18 to 64 (the “workers”). • Fewer workers supporting more older people • So old age dependency ratio is INCREASING
Other ratios… • Childhood dependency ratio - % population age 0-17 compared to % population 18 to 64. • This is DECLINING • Overall dependency ratio - STABLE