In general, counties with larger urban centers did better than those without. Places like Philadelphia, which added 3,900 residents last year, or Lehigh County, which gained 2,800 residents.

Much of this net growth, Vitiello explained, was attributable to influxes of immigrants and young people, attracted to opportunities in cities. Places like Philadelphia, Allentown, or Lancaster have become attractive and comparatively low-cost alternatives to places like New York City. And they offer a range of low-paying but accessible job opportunities — everything from restaurant jobs to Amazon warehouse stock positions or agricultural work.

There were some outliers — college towns often grew, despite their sometimes remote locations. Centre County, which is home to Penn State, continued to record comparatively robust population growth compared to neighboring areas.

But Erie and Allegheny County, which is home to Pittsburgh, along with much of the western third of the state, recorded small decreases in population. Vitiello attributed many of these losses to the continuing impacts of deindustrialization in a region that grew around the fading steel and coal production.

But Western Pa. once shed far more residents than it does today. And just as few Pa. counties saw large gains in population, few saw major losses. This was particularly true when compared to faster growing states, which tend to see both intense population booms and busts.

Vitello said this tracked with the historically slow and modest shifts in the state economy.

“We’ve been growing again in Philadelphia for a little more than a dozen years, but it’s been very modest growth and uneven growth,” Vitello said. “We’re an older state with relatively slow growth, even though we’ve experienced more significant immigration since the 1990s, particularly in the Southeast.”

But population is just a number. And while a growing population is often linked to positive benefits — a bigger tax base and a growing economy — it’s not the only measure of a place. Vitiello said that Pittsburgh, for example, had seen strong economic growth despite its home county’s continued pattern of population decline.

“Pennsylvania remains very much a Rust Belt state,” he said. “But it’s heartening that we’re not declining as precipitously as we were in the 1970s or 1980s.”