The shrinking working-age population

About 80% of U.S. counties lost prime working-age adults between 2007 and 2017, and 65% will lose more over the next decade.

Why it matters: While population decline is affecting parts of every state, the loss of the working-age population is being felt most acutely in places that are already struggling economically, according to an analysis by the Economic Innovation Group and Moody's Analytics.

• The shrinking worker population makes it tough for hard-hit regions to bounce back. Companies are less likely to invest in places that don't have solid pools of workers. Likewise, it's hard to lure more young, educated workers to a place without many employers.
• EIG has pitched the idea of place-based visas, or "heartland visas," allowing communities with chronic depopulation to opt-in to hosting visa-holding immigrants to address labor shortages.

What's happening: Some cities in the Midwest with dwindling labor forces are open to having immigrants fill empty jobs, as they are more likely to be of working age — between 25 and 64 — than the native-born population.

Driving the news: The U.S. Conference of Mayors this month adopted a resolution supporting heartland visas, noting "mayors around the country are in fact already making welcoming immigrants and refugees centerpieces of their economic development strategies."

• Iowa businesses are relying on immigrants to fill jobs, NPR reports.
• Support for the idea is growing in Michigan and Wisconsin.

The bottom line: Immigration may be the difference between population loss and growth. And as seen in several metros, such as Detroit, Memphis, Dayton and St. Louis, foreign-born migration helped reverse population decline, according to a recent study by New American Economy.