[imgcontainer] [img:diversityage.gif] [source]Southern Rural Development Center[/source] The more diverse the county, the lower the median age. This chart divides the nation’s 3100 counties into ten equal groups, arranged left to right by how ethnically diverse they are. (The least diverse group is on the left.) As the groups get more diverse, their median age declines. The red bars are 2010; the blue bars are 2000. [/imgcontainer]

Rural America is aging more rapidly than its metropolitan counterparts. (See this earlier story about aging in rural counties.)

Why is this the case? 

And can this trend be reversed?

Immigration is known to play a key role in not only helping the population grow but also providing young workers. It is estimated that by 2050, nearly one in five Americans will be an immigrant. 

A study by the Pew Research Center found that Hispanics accounted for 54% of labor force growth during the 2000-2010 decade and are expected to account for 74% of growth in the 2010-2020 decade. 

So, is there a relationship between immigration (measured by ethnic diversity) and age (measured by the median age) at the county level in the U.S.? Do these relationships change between metropolitan, small city, and rural counties?

The answer to both questions is yes. Counties that are growing older are less diverse than counties with lower median ages. And rural counties are growing older than counties in metro areas.

In order to address these questions, we looked at three variables: median age; old-age dependency ratio; and an ethnic diversity measure.  We looked at these variables at two points in time: 2000 and 2010. 

Measuring Old-Age Dependency

The old-age dependency ratio is used extensively by social scientists to better understand demographic trends. This ratio calculates the number of residents over 64 years of age for every 100 residents of working age (between 16 and 64). Ratios ranged from a low of 4.1 — that is, 4.1 people over 64 to every 100 of working age  — to a high of 89.2 in 2010 among U.S. counties. 

As with ethnic diversity, all geographic areas witnessed an upswing in their old-age dependency ratio over the 2000 to 2010 time period.  (See the chart below.)

[imgcontainer] [img:dependency.gif] [source]Southern Rural Development Center[/source] The chart shows the number of residents over 64 years of age for every 100 people of working age in rural counties, urban counties and counties with small cities (those between 10,000 and 50,000). The red bar shows the old-age dependency figure in 2010; blue is 2000. [/imgcontainer]

But the magnitude of the old-age dependency ratio remained highest in our nation’s rural counties. 

By 2010, the number of senior citizens per 100 persons 16-64 years of age surpassed the 29 mark in rural counties, with the ratio slipping to 24.4 in small cities and 21 in metropolitan counties.  Clearly the “aging in place” phenomenon remains significant in rural America.   

Diversity and Rural America

To indirectly measure immigration we used an ethnic diversity score.  It ranges from no diversity (in a county where everyone was of the same ethnicity the score would be zero) to greater diversity (a maximum score of 100). These scores were calculated for all counties (more than 3,100). The scores ranged from a low of 0.4 (almost no diversity) to a high of 75.6 in 2010.  

(Alesina et al (1999) developed an ethnic diversity index when looking at the type of public goods cities have available. Citation: Alesina, A., Baqir, R., and Easterly, W. (November 1999). Public Goods and Ethnic Divisions, The Quarterly Journal of Economics, 114(4), 1243-1284.)

[imgcontainer] [img:diversity.gif] [source]Southern Rural Development Center[/source] All parts of America grew more ethnically diverse between 2000 and 2010, but metro counties diversified faster than rural counties. The gap between metro and rural counties expanded. [/imgcontainer]

As expected, the U.S. overall became more diverse between 2000 and 2010. The nation’s ethnic diversity score grew from 23.2 in 2000 to 26.5 in 2010. Metropolitan counties experienced a similar trend over the same time period, with their diversity score swelling to 31.5 in 2010. 

Rural counties became more diverse between 2000 and 2010. But the level of diversity in rural America was nearly 10 points lower than that found in metropolitan counties. 

Old Age, Diversity and Median Age

What impact does immigration have (measured by ethnic diversity), if any, on the old-age dependency and median age?  Based upon our analysis, statistically significant relationships were found among these variables. 

To better understand these relationships, all counties in the nation were divided into ten equal groups (310 counties each) based on their ethnic diversity, ranging from the least diverse to the most diverse.  Average median age and old-age dependency ratios were calculated for each of these groups of 310 counties.

As shown in the graph at the very top of this story, the less diverse counties, on average, were older than counties with more diversity in 2000. 

This relationship not only continued by 2010, but got stronger.  

The least diverse counties had on average a median age of 40.3 years in 2000 compared to 34.4 years for those counties with greater ethnic diversity. By 2010, the difference in average median ages between the less diverse and more diverse counties increased from 5.9 years to 8.1 years.

A similar relationship can be found between ethnic diversity and old-age dependency ratios. The less diverse counties, on average, had a higher age-dependency ratio compared to more diverse counties. 

[imgcontainer] [img:diversitydependency.gif] [source]Southern Rural Development Center[/source] As counties became less diverse, their old age dependency increased. [/imgcontainer]

That is, the least diverse counties had an age-dependency ratio of 30.6 in 2000 compared to 19.4 in the counties classified in the group of 310 counties with the most diverse populations. 

By 2010, the less diverse counties had a 31.4 old-age dependency ratio compared to 19.2 in the more ethnically diverse counties. In fact, the old-age dependency ratio shows a slight decrease in the most diverse counties between 2000 and 2010 (19.4 in 2000 to 19.2 in 2010)

 These results raise a number of key issues. Counties that are more ethnically diverse have a number of opportunities and challenges that need to be addressed, such as: 

(1) Creating a sufficient number of good paying jobs to meet the expanded pool of workers entering the workforce

(2) Providing the right mix of services needed by younger-aged populations (such as schools and housing)

(3) Developing avenues to build positive relationships among people with different racial/ethnic backgrounds.   

Counties that are less diverse and that tend to have higher old-age dependency ratios are especially challenged. Not only must they find ways to address the health and service needs of an aging population, they must do so at a time when the pool of young adults who can serve as the next generation of leaders is dwindling. 

Exploring strategies to retain and attract young families to these counties will be vital. 

Yet retirement income is also an economic asset to communities. The key is to ensure that the right mix of amenities and services is in place that can attract retirees to these places, many of which are located in rural areas of the U.S. 

Roberto Gallardo is a Community & Economic Development Specialist at Mississippi State University’s Southern Rural Development Center and an assistant extension professor. Bo Beaulieu is director of the Southern Rural Development Center. Monica Rosas is a Research Associate at the Social Science Research Center at Mississippi State.

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