Population Structure and Characteristics Part Three Population Structure and Characteristics

Part Outline 8 The Age Transition 9 Population Aging 10 The Family and Household Transition 11 The Urban Transition

Chapter 8 The Age Transition

Chapter Outline The Concepts of Age and Age Cohorts The Concepts of Sex and Gender Measuring the Dynamics of the Age Transition The Age Transition Age Transitions at Work

Age and Age Cohorts Society assigns social roles on the basis of age and gender. Younger people are treated differently from older people. Different kinds of behavior are expected of people as they move through different ages.

Age Stratification Theory Societies distribute resources unequally by age. These resources include economic goods as well as social approval, acceptance, and respect. Age strata, and the prestige and power associated with each, are influenced by the needs of society and by characteristics of people at each age.

Aspects of Human Society that Vary by Age and Sex Category Characteristic or Activity Demographic Being sick and having restricted activities Dying Being sexually active Having a baby Moving or migrating

Aspects of Human Society that Vary by Age and Sex Category Characteristic or Activity Social Getting married/divorced Being involved in religious organizations and activity Being involved in political organizations and activity

Aspects of Human Society that Vary by Age and Sex Category Characteristic or Activity Social School enrollment Level of educational attainment Being involved in criminal behavior

Aspects of Human Society that Vary by Age and Sex Category Characteristic or Activity Economic Being in the labor force Occupation within the labor force Current income Level of accumulated wealth

Lexis Diagram: Relationship between Cohorts and Period Data

Age Cohorts and Age Strata Are Closely Intertwined

Sex Ratios by Age in Selected Countries, 2004

Dynamics of the Age Transition A population with 35% or more of its people under age 15 is “young.” A population with 12% or more of its people aged 65 or older is “old.” As the proportion of young people increases relative to the total, the population “grows younger.” An aging population is one in which the proportion of older people is increasing relative to the total.

The Age Structure There are three major ways to quantify the age structure: Average age of a population Dependency ratio Growth rates by age

Population Pyramids

Changes in Number and Rate of Growth at Specific Ages China India Growth rate Absolute change Age Group 1980– 2000 0–4 –0.15 –3,004 0.84 17,606 5–9 –0.97 –21,938 1.26 25,339 10–14 –0.50 –12,434 1.55 29,112 15–19 –0.35 –7,358 1.79 30,747 20–24 0.63 11,590 1.78 26,618

Changes in Number and Rate of Growth at Specific Ages China India Growth rate Absolute change Age Group 1980– 2000 25–29 1.52 31,810 2.36 31,516 30–34 3.25 60,631 2.81 32,939 35–39 3.53 53,163 2.93 30,165 40–44 2.71 35,142 2.74 24,902 45–49 3.11 39,765 18,338

Changes in Number and Rate of Growth at Specific Ages China India Growth rate Absolute change Age Group 1980– 2000 50–54 2.27 22,796 2.12 13,572 55–59 1.69 13,395 2.15 11,304 60–64 2.26 15,068 2.36 10,077 65–69 2.78 14,957 2.56 8,375

Changes in Number and Rate of Growth at Specific Ages China India Growth rate Absolute change Age Group 1980– 2000 70–74 2.75 10,615 2.74 6,121 75–79 3.09 7,278 3.20 4,113 80+ 4.90 7,203 4.93 3,963

Stable and Stationary Populations In a stable population neither the age-specific birth rates nor the age-specific death rates have changed for a long time. A stable population could be growing at a constant rate or declining at a constant rate. If a stable population is unchanging, we call it a stationary population.

Global Distribution of Younger and Older Populations

Age Structure of Immigrants to U.S., 2002

Age Pyramids for U.S. With and Without International Migration

Age Structure of U.S.

Changing Age Structures in China, U.S. and Mexico