How Population Growth Is Straining America’s Hospital System

This story isn’t unique to Houston. It’s playing out across the country in communities where demographic change is reshaping local populations faster than the healthcare system can adapt.

A new paper by Tuck professor Katharina Lewellen, with Giorgo Sertsios and Jiadi Xu of the University of Wisconsin–Milwaukee, digs into what these changes mean for hospitals—the backbone of the American health care system, and institutions that often operate on razor-thin margins. The study, No Margins, No Mission: The Effects of Immigration on the Hospital Sector, uses two decades of county-level data to examine a deceptively simple question: What happens to hospitals when the number of uninsured patients grows?

What the researchers found says less about newcomers and more about a financing system that strains under the weight of population growth.

Rising Demand, Unsteady Ground

For years, in-migration has driven much of the nation’s population growth. Many of these new residents work in industries with low rates of employer health coverage, and some fall into gaps created by federal and state eligibility rules. When they get sick or injured, hospitals—especially emergency departments—often serve as their only access point for care. As Lewellen puts it, “When you have no insurance and get sick, you will often receive medical care in some way. So it’s a question of how—who will provide and fund it.”

To study this question, the researchers used a clever approach. They looked at long-standing community patterns—places where people from particular countries have historically settled—to predict population inflows over time. That allowed them to focus on how hospitals respond to changing demand, independent of local economic booms or busts.

The results are sobering. A modest 1 percent increase in population growth tied to in-migration leads to a 2.17 percent decline in hospital bed capacity over ten years. For a typical county, that means losing about 7.5 percent more beds compared to regions with slower demographic change.

It’s not because communities don’t need the care—it’s because many hospitals can’t afford to provide it without the financial buffer of insured patients.

The Hospitals That Stay—and the Ones That Go

Not all hospitals feel this pressure the same way. The study found that nonprofit hospitals, which operate most of the nation’s hospital beds and often see themselves as community anchors, are the ones most likely to shrink or close when uncompensated-care costs rise. Their margins are thin to begin with—about 3.6 percent on average—and a 1 percent increase in population growth cuts those margins by roughly 0.4 percent.

Public hospitals, supported by government budgets, tend to expand to meet demand. For-profit hospitals hold steady, focusing on services and locations where patients can pay. But nonprofits—caught between mission and math—are the ones that merge, downsize, change ownership, or disappear altogether.

Harris County provides a vivid example. As new residents continued to arrive in the 2010s and 2020s, nonprofit hospitals consolidated or delayed investment. Meanwhile, the public Harris Health System moved in the opposite direction, planning upgrades and approving nearly 100 new beds at Ben Taub.

The pattern reveals a stark truth: the system relies on mission-driven nonprofits but doesn’t give them the financial tools to fulfill that mission in fast-growing communities.

Mission Meets Reality

Lewellen and her co-authors tracked how nonprofits respond when their finances tighten. They don’t tend to boost fundraising or take on substantial debt. Instead, they scale back on the very investments—modern equipment, facility upgrades, expanded capacity—that keep hospitals strong over time. In metro areas, a 1 percent rise in population growth corresponds to a 5.5 percent decline in fixed assets.

In other words, the hospitals that are most committed to serving everyone are the ones least able to absorb rising demand.

“What really surprised us was that the number of beds actually declines,” Lewellen says. “Some nonprofits just get pushed out. They close.”

What This Means Going Forward

The authors are clear: this isn’t a story about newcomers overwhelming the system. It’s a story about a system not built to handle the gaps in how Americans get—and don’t get—health insurance.

As long as hospitals are expected to make up for those gaps, and if their financial stability depends on a delicate balance of insured and uninsured patients, population growth will keep exposing the limits of the model.

If policymakers want nonprofit hospitals to remain central to American healthcare—especially in diverse, fast-growing regions—they’ll need to rethink how uncompensated care is funded. For now, public hospitals are serving as the fallback.

Or as Lewellen puts it: “Nonprofits are filling the holes in our insurance landscape. And when they can’t, the rescuer of last resort is the government hospital.”