Why is Custer County Different? Median Age in South Dakota Are old people flocking to Custer County or is everyone under the age of 19 leaving? Or is it just growing older faster than all of the other counties? Custer County is different-unique. Many of South Dakota’s counties are also experiencing an increase in the median age. Their increase is due to the out-migration of young people around the age of 20 which leaves older residents but not Custer County. Custer County is experiencing an in-migration of people even though 20 year olds are leaving for college. The ages of those moving in are older. Many are preparing for retirement or are retired, and they are contributing to the increase in the median age for that county. Median age is a measurement of centrality—the midpoint of a distribution. One half of the population falls above the median age (the midpoint) and one half falls below. If the median age increases from one Census to the next, it indicates that one half of the population falls above and below a higher age number (the midpoint). Thus the interpretation is that the population for that area is growing older. If the median age is lower than a previous Census, the interpretation is that the general age of the population is growing younger. The table below shows the median age for the United States and South Dakota since 1890.
Median Age: South Dakota & United States 40 35 Median Age
30 25 20 South Dakoa
15
US
10 5 0 10 20 00 20 90 19 80 19 70 19 60 19 50 19 40 19 30 19 20 19 10 19 00 19 90 18
Years
Generally, since 1890 the median age of the United States and South Dakota has
gone up. Both populations have grown older. The dip or decrease in median age between 1950 and 1970 was due to the increased number of births which occurred after WW II. This period has been called the “Baby Boom.” Three factors influence what happens to median age—fertility, mortality, and migration. The term fertility is used to refer to the number of children born to women in a group or geographical area. Mortality, people dying, has had a dramatic impact on the world population growth during the last century because it has declined. This has been due to improvements in health care and nutrition. The third term, migration, refers to the movement of a population. Technically it is when someone has a change in permanent address. Of the three factors, migration can change the population of a community in the shortest time. If a meat packing plant is built in a community and opens, it will attract a large group of people to work and live there. If one closes, people quickly move someplace else to find employment. The two factors which strongly influenced the increase in both the US and South Dakota are mortality and fertility. Except for the baby boom period, fertility rates in both have been declining. Fewer people are being born. This trend would influence a rise in the median age. In terms of mortality, more people have been living longer especially those who reach age 65. This is the result of better nutrition, living conditions, and better health care. This trend would also contribute to the rise of the median age. South Dakota’s median age has also been influenced by migration—largely out-migration. Young residents are attracted to urban areas because of job opportunities. This tends to increase the percentage of older people who remain in rural areas. While the median age trends for the US and South Dakota have somewhat paralleled each other, the median age for South Dakota’s counties has wider variation. The median age for each county for the 1990 and 2000 Censuses is displayed below.
MEDIAN AGE By County AREA South Dakota Aurora Beadle Bennett Bon Homme Brookings Brown Brule Buffalo Butte Campbell Charles Mix Clark Clay Codington Corson
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1990 AGE RANK 32.5
2000 AGE RANK 35.6
38.6 35.5 29.2 37.6 26.3 33.0 32.6 22.1 34.4 39.2 33.9 38.8 24.0 32.9 27.9
40.6 40.1 29.2 40.3 26.6 37.2 36.9 23.4 38.0 41.9 35.7 41.6 24.9 35.3 28.3
18 31 58 24 60 45 47 64 37 10 39 16 63 46 59
49 23 58 28 60 39 44 64 32 15 48 19 62 50 59
1990 AGE RANK 36.7 26 33.6 41 38.7 17 38.9 12 25.8 61 36.8 25 40.1 5 40.9 3 39.5 8 34.9 34 38.1 21 31.9 51 37.7 23 38.1 21 34.6 35 32.2 50 33.3 43 41.7 2 39.4 9 30.0 56 40.4 4 36.4 27 39.7 6 33.8 40 32.4 49 33.2 44 31.4 52 38.3 20 47.0 1 38.9 12 29.8 57 30.3 54 38.9 12 31.4 52 34.1 38 30.1 55 38.6 18 38.9 12 35.5 31 36.0 29 20.5 66 36.2 28 32.6 47 35.6 30 21.0 65 34.5 36 39.0 11 35.0 33 39.7 6 33.5 42 24.5 62
AREA Custer Davison Day Deuel Dewey Douglas Edmunds Fall River Faulk Grant Gregory Haakon Hamlin Hand Hanson Harding Hughes Hutchinson Hyde Jackson Jerauld Jones Kingsbury Lake Lawrence Lincoln Lyman McCook McPherson Marshall Meade Mellette Miner Minnehaha Moody Pennington Perkins Potter Roberts Sanborn Shannon Spink Stanley Sully Todd Tripp Turner Union Walworth Yankton Ziebach
2000 AGE RANK 43.2 7 36.0 47 42.9 10 40.8 25 26.5 61 41.8 16 41.6 18 45.5 4 41.5 20 40.3 27 44.3 5 41.3 21 38.0 33 43.6 6 36.0 46 37.6 36 37.5 37 43.1 9 42.2 14 30.6 57 46.3 2 41.1 22 42.7 12 36.5 45 37.2 38 34.0 53 34.5 52 38.6 31 47.6 1 41.6 17 33.4 55 32.1 56 42.5 13 33.5 54 37.0 42 35.0 51 43.1 8 45.8 3 37.1 40 40.8 66 20.6 24 39.9 29 37.6 35 40.0 34 21.7 65 39.5 30 40.5 26 36.9 43 42.8 11 37.0 41 23.8 63
In 1990 South Dakota’s median age was 32.5. The counties with the highest median age included McPherson (47.0), Hutchison (41.7), Fall River (40.9), Edmunds (40.1), and Jerauld (36.4) having one half of their residents fall above the age listed. The counties with the lowest median age were Shannon (20.5), Todd (21.0), Buffalo (22.1), Clay (24.0), and Ziebach (24.5).
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In the 2000 Census South Dakota’s median age was 35.6. The counties with the highest median age were McPherson (47.6), Jerauld (46.3), Potter (45.8), Fall River (45.5), and Gregory (44.3). The counties with the lowest median age were Shannon (20.6), Todd (21.7), Buffalo (23.4), Ziebach (23.8), and Clay (24.9). MEDIAN AGE DIFFERENCE By County AREA South Dakota Aurora Beadle Bennett Bon Homme Brookings Brown Brule Buffalo Butte Campbell Charles Mix Clark Clay Codington Corson Custer Davison Day Deuel Dewey Douglas Edmunds Fall River Faulk Grant Gregory Haakon Hamlin Hand Hanson Harding Hughes Hutchinson Hyde Jackson Jerauld Jones Kingsbury Lake Lawrence Lincoln Lyman McCook McPherson Marshall Meade Mellette Miner Minnehaha Moody Pennington
1990-2000 YEARS RANK 3.1 2.0 4.6 0.0 2.7 0.3 4.2 4.3 1.3 3.6 2.7 1.8 2.8 0.9 2.4 0.4 6.5 2.4 4.2 1.9 0.7 5.0 1.5 4.6 2.0 5.4 6.2 9.4 0.3 5.5 1.4 5.4 4.2 1.4 2.8 0.6 5.9 4.7 3.0 2.7 4.8 0.8 3.1 0.3 0.6 2.7 3.6 1.8 3.6 2.1 2.9 4.9
1990-2000 PERCENT RANK 9.5 42 16 65 35 61 21 20 53 25 36 46 33 54 39 60 3 40 22 44 56 9 49 17 43 7 4 1 62 6 51 8 23 52 34 58 5 15 31 37 13 55 29 63 59 38 26 47 27 41 32 12
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5.2 13.0 0.0 7.2 1.1 12.7 13.2 5.9 10.5 6.9 5.3 7.2 3.7 7.3 1.4 17.7 7.1 10.9 4.9 2.7 13.6 3.7 11.2 5.1 15.5 16.3 29.5 0.8 14.4 4.0 16.8 12.6 3.4 7.1 2.0 14.6 12.9 7.6 8.0 14.8 2.4 9.9 0.8 1.3 6.9 12.1 5.9 9.3 6.7 8.5 16.3
46 16 65 35 61 18 15 42 25 39 45 36 52 34 59 2 37 24 48 56 13 53 23 47 7 5 1 62 12 50 4 19 54 38 58 10 17 33 31 9 57 28 63 60 40 21 43 29 41 30 6
AREA Perkins Potter Roberts Sanborn Shannon Spink Stanley Sully Todd Tripp Turner Union Walworth Yankton Ziebach
1990-2000 YEARS 4.5 6.9 1.6 4.8 0.1 3.7 5.0 4.4 0.7 5.0 1.5 1.9 3.1 3.5 -0.7
1990-2000 RANK 18 2 48 14 64 24 10 19 57 11 50 45 30 28 66
AREA 11.7 17.7 4.5 13.3 0.5 10.2 15.3 12.4 3.3 14.5 3.8 5.4 7.8 10.4 -2.9
1990-2000 YEARS 22 3 49 14 64 27 8 20 55 11 51 44 32 26 66
The above table presents the difference in the median age from 1990 to 2000. The numerical difference indicates the direction of the trend and answers the question, “Is the median age going up, down or staying the same?” The median age for South Dakota increased by 3.1 years (Table 3). That was a proportional increase (Table 4) of 9.5% over the 1990 median age. South Dakota’s counties which had the highest numerical increases were Haakon (9.4), Potter (6.9), Custer (6.5), Gregory (6.2), and Jerauld (5.9). Those with the lowest increases were Ziebach (-0.7), Bennett (0.0), Shannon (0.1), Hamlin (0.3), Brookings (0.3), and Corson (0.4). Ziebach County’s median age actually decreased, and Bennett County’s had no change. Table 4 shows the proportional increases of each county over their 1990 median age. Those counties with the highest proportional increases were Haakon (29.5), Custer (17.7), Potter (17.7), Harding (16.8), and Gregory (16.3). Those with the lowest proportional increases were Ziebach (-2.9), Bennett (0.0), Shannon (0.5), McCook (0.8), Hamlin (0.8), and Brookings (1.1). Interpreting Median Age As stated earlier median age is a general indicator of the age of a population of an area. By noting its rise or fall from one Census to another one can make comparisons and track what is happening to the age of the population. Two additional data sets can help provide information for interpretation—the migration rate (See “South Dakota County Data Book,” http://sdrurallife.sdstate.edu/newcomunity/databook.htm) and the population pyramid (See “Population Pyramids,” http://sdrurallife.sdstate.edu/pop/populationspyramids.htm) for the county under study. The net migration tables show that the counties having the highest increases in median age both in number of years and in percentage of years gained also have high outmigration rates. Custer County, as mentioned above, is the exception. When consulting the population pyramids for the same counties, all have a significant out-migration at the age 20-24 part of the pyramid. This reflects young adults leaving for college or to find employment elsewhere. 5
The exception of Custer County experiencing in-migration, 20 years olds leaving for college, and an increase in the median age at the same time is unusual when compared to South Dakota’s other counties. To determine what is happening a more detailed analysis is needed. Comparing Custer County’s 1990 and 2000 Population Pyramids can be helpful (See below). We know that the total population has increased. But the number of births in the past 10 years has declined. This is indicated by the decreasing bars at the bottom of the 2000 Pyramid. The bars representing the ages of 20-34 are smaller in the 2000 Pyramid than in the one for 1990. Out-migration for college or employment could account for this difference. The bulge representing the Baby Boom has aged 10 years and is now at the 40—54 age levels. The Baby Boomers are aging. This would influence the aging of the population. In addition to the aging of the baby boomers, the age cohorts for the 55 + have more people in them in 2000 than in 1990 especially the 75+ group. One can assume that many in this age group have in-migrated and contributed to the increase in the median age. An additional interesting item on the 2000 pyramid is the bar representing the 15-19 year old males. It is larger than the one for 1990. This bar is influenced by the creation of the boot camp for teenage males.
age cohorts
Custer County 1990 Total Population = 6,179 75+ 70--74 65--69 60--64 55--59 50--54 45--49 40--44 35--39 30--34 25--29 20--24 15--19 10--14 5--9 0--4
males
8
6
females
4
2
0 percent
6
2
4
6
8
age cohorts
Custer County Population Pyramid 2000 Total Population = 7,275 75+ 70--74 65--69 60--64 55--59 50--54 45--49 40--44 35--39 30--34 25--29 20--24 15--19 10--14 5--9 0--4
males
8
6
females
4
2
0
2
4
6
8
percent
Utilizing Median Age Median age is quick indicator of what is happening to an area’s population in regard to age. It takes on more meaning when other indicators are also included into planning and decision making discussions. The decisions would be different for an area that has an increasing median age due to in-migration of older residents who might be retiring as in Custer County. This in-migration coupled with the aging of the baby boomers should focus the attention of planners and community leaders on the issues of health care, housing, transportation, and nutrition for seniors. Another county that experiences an increase in median age due to the out-migration of young people has different issues with which to deal such as developing employment opportunities that will support families. When citizens of South Dakota decide to analyze their present situations, discuss and plan options for their future, and begin to implement those plans, they need to include median age as one of the demographic planning tools in order to make more informed decisions. Sources: http://sdrurallife.sdstate.edu US Census Bureau at www.census.gov Weeks, John R. 2002. Population: An Introduction to Concepts and Issues. 8th ed. Belmont, CA: Wadsworth/Thomson Learning.
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David P. Olson & Dr. Donna Hess Census Data/Rural Life Center 202 Scobey Hall SDSU Brookings, SD 57006 605/688-4899 Email:
[email protected] Website: http://sdrurallife.sdstate.edu March, 2003
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