In statistics, the median is not a strip of grass down the middle of the highway. The median is the number with half of all values above and half below.
Thus, the 2011 median age of the United States is 37.3 years, a number that increased by 1.9 years since 2000. We’re getting older, individually and collectively.
Indiana’s population, with a median age of 37.1 years, is only slightly younger than the nation. We’re aging at about the same pace as the rest of the country. Yet these numbers hide the diversity of the nation.
Maine has the oldest population with a median age of 43.2, followed by Vermont and New Hampshire, then West Virginia, before we get to everyone’s guess: Florida (41.1). The youngest population (29.5) is found in Utah, followed by Texas, Alaska and Idaho.
It is easy to speculate about the significance of these numbers. Older populations require more medical attention; younger groups need more educational services. Younger families are bigger buyers of household goods while the older folks are polishing their antiques.
The differences of median age within Indiana are greater than the differences between states. Where the range for the nation was 43.2 to 29.5 (a spread of 13.7 years), the range in Indiana is 47.4 (Brown County) to Tippecanoe’s 27.6 (a spread of 19.8 years). This fits with our images of rocking chairs in Brown County and school desks in Tippecanoe.
Another way of looking at age data is the dependency ratio. This simple number takes the population under 25, plus the population 65 and older, and divides that sum by the “working age” population (25 to 64 years).
Don’t bother to complain that many people over 65 are not dependent on younger folks. Keep your hair shirt on when you tell me that not all college age persons are living off their parents.
The dependency ratio is a convenient way of looking at a population, and in the social sciences convenience trumps perfection.
Indiana’s dependency ratio for 2011 was 91 per 100, meaning, in its most simplistic form, that it takes 100 persons to “support” 91 persons in the dependent ages.
With many college students, Monroe, Tippecanoe and Delaware are among the top four counties ranked by dependency, each exceeding 120 per 100. Yet, it should be clear that most of the students do not depend on the working population of their host counties. They depend on Mom and Dad who live in other counties, even in other states.
At the other end of the scale is Brown County where the dependency ratio is just 79 per 100. Immediately following Brown County is Hamilton where there are many school age children, but Hamilton has the lowest percentage of college age students among the 92 counties. Those young people are off in Monroe, Tippecanoe, Delaware and other college counties nationwide.
While these numbers are helpful in understanding the dynamics of individual counties, prophets and fortunetellers would do well to avoid detailed scenarios of the economy and politics based on demographic factors alone.
In the words of “The Music Man,” “you gotta know the territory.”