Indiana's prime-age population projections

The size of Indiana’s population between the ages of 25 and 54 increased by more than 270,000 residents per decade between 1970 and 2000. However, over the next 20 years—a period during which the baby-boom generation aged out of this group—the size of Indiana’s population between the ages of 25 and 54 fell by nearly 28,000 residents per decade. This marked the first time in the state’s history that the size of this prime-age population—so called because this is the age bracket for peak labor force participation and new household and family formation—declined over any extended stretch.

Looking ahead, a strong net in-migration of residents in recent years coupled with the coming-of-age of the Generation Z cohort (or residents born between 1997 and 2012)—which in Indiana is larger than the millennial cohort—will likely result in a modest rebound in the size of the state’s prime-age population in the near term. In fact, we expect Indiana’s population ages 25 to 54 to grow by roughly 99,000 residents per decade between 2020 and 2040.

After 2040, however, our projections show the size of this age group beginning to fall again, due largely to the state’s ongoing decline in fertility rates—a trend that began in 2007 and only seems to be accelerating the longer it endures.¹   

Beyond these relatively minor ebbs and flows, the key takeaway from these numbers is that the era of consistently strong growth in the size of Indiana’s prime-age population has ended (see Figure 1). To illustrate this point: Over the 60-year period between 1940 and 2000, the number of Hoosiers ages 25 to 54 increased by more than 1.2 million residents. By contrast, our projections show that over the subsequent 6 decades—from 2000 to 2060—the size of this group will grow by only 38,000 residents in total. This shift will have significant implications for the size of Indiana’s labor force and economic growth in the state.²

If recent demographic dynamics persist, the size of this age group would surely continue to fall if we extended the projection horizon beyond 2060.

Figure 1: Indiana population ages 25 to 54

Notes: Blue columns are actual data while red columns are projections. 2020 value is from the vintage 2022 population estimates.
Source: U.S. Census Bureau and Indiana Business Research Center

Around Indiana

By 2030, 61 of the state’s 92 counties are projected to see at least some growth in the size of their prime-age populations. Between 2030 and 2050, however, only 18 counties will continue to see gains in this age group.

All told, suburban counties in the Indianapolis metropolitan area will lead the way—with Boone, Hamilton, Hendricks and Hancock counties each expected to see this group expand by at least 44% over the next three decades. Outside of central Indiana, other communities projected to see growth include Warrick, Clark, Allen and Bartholomew counties.

Meanwhile, the state’s midsize and rural communities as a group will likely begin to see sharp declines in this age group after 2030. As Figure 2 shows, the prime-age population in rural Indiana is projected to fall 10% by 2050.³ Similarly, the state’s midsize communities—or micropolitan areas (meaning counties with a city or town that has a population between 10,000 and 50,000 residents)—will have a 5% drop. The 44 counties that are part of a metropolitan statistical area will combine for a projected 10% gain over the same period, although even metro Indiana as a group is projected to start seeing a decline after 2045.

Figure 2: Projected cumulative change for population ages 25 to 54 by county type

Source: Indiana Business Research Center

Use the following interactive data visualization (Figure 3) to learn more about projected changes to prime-age populations in Indiana counties.

Interactive figure 3: Projected change for population ages 25 to 54 by county

Source: Indiana Business Research Center

Migration and public health improvements will be key

These population projections are not set in stone, of course. Any significant shifts in the demographic drivers of change can lead to different outcomes, and the actions of state and local units of government—along with leaders in business, nonprofits and philanthropy—will influence whether Indiana or its communities ultimately overperform or underperform these numbers. For the prime-age population, this means a focus on attracting and retaining more young adults, as well as improving Hoosier health.

With respect to migration, a continued strong net inflow to the state is a critical assumption in our population projections (see Figure 4). If Indiana were to fall short in this measure over the coming decades, our projections for the state’s prime-age population will likely be too high.  

Figure 4: Indiana’s net migration by decade

Note: Net migration values are in thousands. Blue columns are actual data while red columns are projections.
Source: Indiana Business Research Center, using data from the National Center for Health Statistics, Indiana State Department of Health and the U.S. Census Bureau

When looking at age-specific migration trends in recent years, Indiana tends to attract families with children and college students, while losing young adults. Over the last two decades, in fact, the state has had a cumulative net outflow of nearly 50,000 residents between the ages of 25 and 34—many of whom are surely recent college graduates (see Figure 5). Continuing to develop strategies to attract and retain more young adults will have to be a top priority for Indiana and its communities.

Figure 5: Indiana net migration by age and decade

Source: Applied Population Laboratory, University of Wisconsin - Madison

There is a potential hitch in this plan, however. As referenced earlier, fertility rates have been in steep decline around the country. Between 2007 and 2023, Indiana’s fertility rate has fallen by 15%, which—believe it or not—ranks as the 8th-best performance among states.⁴ The U.S. fertility rate is down 21% over this span and is still falling. To highlight the impact of this shift, the U.S. would have had 10.6 million more births over the last 16 years if fertility rates had held steady at 2007 levels.⁵

As we move forward, then, employers and communities will be competing over a progressively smaller pool of young adults, at least with respect to the domestic population. As a result, Indiana will likely need to see continued gains in the size of its foreign-born population in this age group to help offset eventual declines among U.S.-born residents, as has been the case since 2000 (see Table 1).  

Turning to the state’s public health record, Indiana’s mortality rate for its population between the ages of 25 and 54 increased by 24% between 1998 and 2019. The COVID-19 pandemic and a further escalation in the drug overdose crisis combined to drive mortality rates for this group to much higher levels in 2020 and 2021. After recovering over the next two years, the mortality rate for Indiana’s prime-age group in 2023 was still 6% higher than in 2019 (see Figure 6). Due primarily to rising mortality in this age group, Indiana life expectancy has largely been in decline since 2010.⁶

Figure 6: Mortality rate for population ages 25 to 54, 1970 to 2023

Notes: Rates from 1970 to 2019 are three-year moving averages. Rates from 2020 to 2023 are annual values. 2023 rates are provisional.
Source: National Center for Health Statistics

One way to add context to these changes is to estimate how many Indiana deaths in this age group would be prevented if Indiana’s mortality rates were the same as in a comparison region. For this analysis, we used the average mortality rates of the 22 states that comprise the Northeast and West census divisions as our peer area.⁷

As Figure 7 shows, the number of potentially preventable deaths among Indiana’s prime-age population has been on a steep and steady climb for more than two decades. The state has had more than 2,000 potentially preventable deaths in this age group each year since 2017. The 2,190 excess deaths in 2023 accounted for 28% of all deaths in this age group.

Any sustained success in public health efforts to address the causes of this crisis and begin to reduce these numbers will have positive impacts for Indiana’s population growth and the state’s economy. 

Figure 7: Indiana potentially preventable deaths for population ages 25 to 54

Notes: Counts of potentially preventable deaths are three-year averages (e.g., 2023 is an average of 2021 to 2023). Values are derived from age-adjusted mortality rates for the 25-to-54 age group.
Source: Indiana Business Research Center, using data from the National Center for Health Statistics

About the projections

The IBRC’s projections are purely demographic, meaning that they rely exclusively on recent birth/death data and migration estimates. Therefore, these figures reflect what Indiana and its communities will look like if past trends continue. No assumptions have been made about future economic conditions, land use decisions or environmental changes. However, State policy will assuredly have an effect, as will the decisions of individual residents and businesses.

Also, some population dynamics can be difficult to project. Migration, in particular, is prone to sudden swings. Therefore, long-range projections can be subject to significant error, and it is often useful to pay greater attention to trends during the first 15 to 20 years of the projections period.

To access the entire population projections data set or to read a detailed methodology, visit the STATS Indiana Population Projections topic page.

To view the Indiana Business Research Center’s labor force projections, visit Hoosiers by the Numbers.

Notes

1. Matt Kinghorn, “Indiana births continue to fall,” InContext, September-October 2024, www.incontext.indiana.edu/2024/sept-oct/article3.asp.
2. Carol O. Rogers, “Labor force projections: Age matters,” Indiana Business Review, Fall 2024, www.ibrc.indiana.edu/ibr/2024/fall/article1.html.
3. Notes: County-level projections cover 2020 to 2050. In this article, “rural” refers to any county that is not designated as being part of either a metropolitan or micropolitan statistical area by the U.S. Office of Management and Budget.
4. Matt Kinghorn, “Indiana births continue to fall,” InContext, September-October 2024, www.incontext.indiana.edu/2024/sept-oct/article3.asp.
5. Kenneth M. Johnson, “U.S. births hit a 43-year low,” Data Snapshot, University of New Hampshire, Carsey School of Public Policy, April 30, 2024, https://carsey.unh.edu/publication/us-births-hit-43-year-low.
6. Matt Kinghorn, “Indiana’s life expectancy falling further behind U.S.,” Indiana Business Review, Summer 2021, www.ibrc.indiana.edu/ibr/2021/summer/article1.html.
7. More information on the approach used in this analysis can be found here: www.incontext.indiana.edu/2022/sept-oct/article1.asp.