Birth Cohorts
Nov. 29, 2006
http://www.iastate.edu/~soc.134
© 2006 David Schweingruber
Basic demographic terms
Demography: the study of human population
Demographer: sociologist who studies trends in
population characteristics
Three major components
 Fertility: the incidence of childbearing in a country’s
population
 Mortality: the incidence of death in a country’s population
 Migration: the movement of people into and out of a
specified territory
©©2006
2000David
DavidSchweingruber
Schweingruber
Birth cohorts
 Birth cohort: set of people who were born during the same era and who
face similar societal circumstances brought about by their shared
position in the overall age structure of the population (p. 463)
 Birth cohorts effect everyday lives in two ways:
• Cohort effect: phenomenon in which members of a birth cohort tend to
experience a particular life event or rite of passage—puberty, marriage,
childbearing, graduation, entry into the workforce, death—at roughly the
same time (p. 463)
• Period effect: phenomenon in which a historical event or major social trend
contributes to the unique shape and outlook of a birth cohort (p. 464)
©©2006
2000David
DavidSchweingruber
Schweingruber
2.5%
High immigration
& birth rates
250,000
Baby boom
2.0%
200,000
1.5%
150,000
1.0%
0.5%
Great Depression,
low immigration
Population
50,000
1995
1990
1985
1975
1970
1965
1960
1955
1950
1945
1940
1935
-0.5%
1930
1925
1915
1910
1905
1920
1918 flu
epidemic
0
0.0%
Growth rate
1980
100,000
Annual growth rate
300,000
1900
U.S. population (thousands)
U.S. population & growth rates,1900-98
©©2006
2000David
DavidSchweingruber
Schweingruber
Total births & birth rates in U.S., 1910-95
Baby boom
45
Echo boom
4,000,000
40
35
Depression
Generation
3,000,000
30
Baby bust
2,500,000
2,000,000
25
20
GI Generation
War babies
1,500,000
15
1,000,000
10
Total births
Birth rate
500,000
5
1995
1990
1985
1980
1975
1970
1965
1960
1955
1950
1945
1940
1935
1930
1925
1920
0
1915
0
1910
Total births
3,500,000
Births per 1,000 people
4,500,000
©©2006
2000David
DavidSchweingruber
Schweingruber
Some generational labels
 GI Generation: 1910s & 1920s
 Depression Generation: 1930-39
 War babies: 1940-45
 Baby Boomers: 1946-1964 (78 million)
 Baby Busters (Gen X): 1965-1979 (60 million)
 Echo Boomers (Millennium Gen, Gen y): 1980-late 90s (7080 million)
©©2006
2000David
DavidSchweingruber
Schweingruber