Age Cohorts: A New Age
Perspective
COMMUNITY INDICATORS
| Community Indicators are intended to stimulate thoughtful dialogue about your community. They can help identify potential issues, opportunities and problems facing your community. This e-newsletter is intended to introduce innovative ways to utilize demographic data more effecitively an thus, increase awareness, knowledge and use of readily accessible demographic data on the web. |
Issue 2, March 2003
By: Bill Pinkovitz
Does Table 1 look familiar? It is one of the most commonly used formats for displaying and analyzing U.S. Census age data. Table 1 provides some useful and thought provoking information. For example, it reveals that during the 1990s, Crawford County Wisconsin experienced significant increases in 40 to 49 year olds (+42.7%) and 50 to 59 year olds (+45.9%). Together, these two age categories increased by 1,459 people (807 + 652) in Crawford County . That is more than the total increase in the County's population (+1,303) during the same period.
Table 1
Population by AGE (1990 and 2000)
AGE
|
Crawford County , WI 1990 |
Crawford County , WI 2000 |
Change in Population 1990 to 2000 |
Percentage Change in Population 1990 to 2000 |
< 10 |
2,500 |
2,131 |
-369 |
-14.8% |
10 to 19 |
2,496 |
2,943 |
447 |
17.9 |
20 to 29 |
1,719 |
1,646 |
-73 |
-4.2 |
30 to 39 |
2,432 |
2,182 |
-250 |
-10.3 |
40 to 49 |
1,891 |
2,698 |
807 |
42.7 |
50 to 59 |
1,419 |
2,071 |
652 |
45.9 |
60 to 69 |
1,584 |
1,469 |
-115 |
-7.3 |
70 to 79 |
1,301 |
1,290 |
-11 |
-0.8 |
80 + |
598 |
813 |
215 |
36.0 |
Total |
15,940 |
17,243 |
1,303 |
8.2% |
SOURCE : American FactFinder , 2000 U.S. Census
What caused the seemingly explosive growth in the number of middle-aged people in Crawford County during the 1990s? Is it simply the pig-in-the-snake phenomenon (the bulge in the population chart caused by the post-World War II baby boom) or is something else happening in Crawford County ?
Age Cohorts can help answer this and other questions by tracking groups of people as they age over time. Age Cohorts remove the effect of t he post-World War II baby boom from the analysis and reveal whether the number of people in an Age Cohort in a community is growing or declining.
This two-part series will provide tools to help answer these and other questions about Crawford County and other communities. First, we will use Age Cohorts to track groups of people as they age over time. This will help determine whether the increase in 40 to 59 year olds in Crawford County is simply caused by aging baby boomers or if large numbers of middle-aged people are moving into the county. The second part of this series, Comparative Communities , will compare Crawford County to other similar counties to help discover whether their growth patterns are similar, or if something unique is happening in Crawford County . As always, we will provide data that will enable you to make similar comparisons for your counties and communities.
Age Cohorts
Using Age Cohorts simply means viewing the age data in Table 1 a little differently. James Schneider, President of Blue Chip Consultants, and other demographers suggest looking at the changes in a group (cohort) as it ages over time. They argue that instead of comparing the 40 to 49 year olds of 1990 to the 40 to 49 year olds of 2000, we should compare apples to apples by following the 40 to 49 year olds of 1990 as they age over time and become the 50 to 59 year olds of 2000. This provides us a different and more dynamic picture of what is happening in a community. Are we losing young people as they leave to go to college, pursue job opportunities outside our community, or retire? Are more people moving into our community or are more leaving to live somewhere else? Table 2 provides some answers for Crawford County .
Table 2
Change in Age Cohorts (1990 to 2000)
Change in Population |
Crawford County Wisconsin |
Percentage Change |
Age in 1990 Age in 2000 |
|
|
< 10 10 to 19 |
443 |
17.7% |
10 to 19 20 to 29 |
-850 |
-34.1% |
20 to 29 30 to 39 |
463 |
26.9% |
30 to 39 40 to 49 |
266 |
10.9% |
40 to 49 50 to 59 |
180 |
9.5% |
50 to 59 60 to 69 |
50 |
3.5% |
60 to 69 70 to 79 |
-294 |
-18.6% |
SOURCE : American FactFinder , 2000 U.S. Census
According to Table 1, the number of 40 to 49 year olds in Crawford County increased by 807 people or 42.7% between 1990 and 2000. Typically, an increase like this is attributed to the effect of aging Baby Boomers. That may be correct, but it does not reveal how much of the increase (decrease) is the result of migration into or out of Crawford County . Table 2 helps answer that question. Following age cohorts over time removes the impact of phenomenon like Baby Boomers from the analysis and enables us to focus on the net migration into and out of a community.
There were 1,891 people age 40 to 49 living in Crawford County in 1990. What happened to these people during the 1990s? Many of them stayed in Crawford County . Some moved out of the county and a few died. Other people in this Age Cohort moved into Crawford County during the 1990s. Table 2 shows the increase of 180 people or 9.5% when we track the 40 to 49 year olds of 1990, as they become the 50 to 59 year olds of 2000 . People moved out of the county. Others moved in. Crawford County realized a net increase of 180 people in this age cohort. That is more than just aging Baby Boomers.
Similarly, we can examine the effect of the Brain Drain on Crawford County . Table 1 reports that the number of 20 to 29 year olds declined by only -73 or -4.2% between 1990 and 2000. It is tempting to declare that there is no brain drain in Crawford County . However, Cohort Analysis reveals that during the 1990s, Crawford County experienced a net loss of -850 people as they aged from their teens to their twenties. In 1990, there were 2,496 residents age 10 top 19 years old in Crawford County . By 2000, the U.S. Census reported only 1,646 people age 20 to 29. That is a net loss of over one-third (-34.1%). Where did they go? The Census data does not tell us where they went or why they left. The data does provide a few hints. For example, the 20 to 29/30 to 39 year old age cohort increased by 463 (26.9%) between 1990 and 2000. Again, the data does not tell us where they moved from, or why they moved to Crawford County . Some people may have moved back home to raise a family after completing college or seeing the world. Employment or the allure of living in a smaller rural community may have attracted others to move to Crawford County . Again, the data answers a few questions, but raises many others.
Are these trends unique to Crawford County , Wisconsin ? Next, we will discuss Comparable Communities . Comparing Crawford County to other similar counties can provide more useful insights into what is happening in Crawford County and help determine whether the growth patterns simply reflect broader trends or, if something unique is happening in Crawford County .
Would you like to be able to generate data and charts like these for your county or community? It is easy. We have done most of the work for you. Simply go to the CCED Website at: http://www.uwex.edu/ces/cced/Indicators_Links.htm and click on the Age Cohort link . Then, download the Excel® spreadsheet and view the Powerpoint® presentation that provides easy step-by-step instructions that will enable you to generate similar data for your county/community.
(50 to 59 year olds in 2000) - (40 to 49 year olds in 1999) = 2,071 - 1,891 = 180. 180/1,891 = +9.5%
