Greater Boston is no longer one of the country’s 10 largest metro areas. How did that happen?

Census reports metro Phoenix overtook Boston in population

A view of Boston's Back Bay skyline from a Brookline rooftop.Lane Turner/Globe Staff

Forget the suddenly mediocre football team in Foxborough. Or the latest failed bid for the White House by a Massachusetts pol.

The region has quietly suffered an even bigger dent to its standing. For the first time in decades, if not all of US history, Greater Boston has lost its perch among the top 10 largest US metro areas. Knocked aside by the booming Phoenix metro area.

So much for Hub of the Universe.

According to US Census Bureau data released earlier this year, Boston was the 11th largest metro area in 2019 with nearly 4.9 million people living in a region that includes five counties in Eastern Massachusetts and a swath of southeastern New Hampshire. Boston had been the 10th largest metro area in recent years.

While the region’s population has grown by 7 percent since 2010, it hasn’t kept pace with hotter metro areas, like Phoenix, which grew by 18 percent during the same period.

Experts cite various explanations. The population of the United States has continued to shift south and west in recent decades. That migration saw Massachusetts lose a congressional seat in 2012, while states like Texas and Florida picked up seats.

Greg Slayden, who has created a web site that documents the history of US metro areas by population, said in an e-mail that there has broadly been a “strong movement of population to cities with vibrant economies, favorable climates, and room for expansion,” for at least a half-century.

“Boston has a strong economy based on knowledge workers and renowned educational institutions, but the cold winters and hot summers are a minus to many people,” Slayden said. “And, as an old city, it is hemmed in by existing suburban jurisdictions with long histories of land-use policies that make it hard to easily build vast new residential or commercial developments, as can be done in, say, Houston or Phoenix.”

It’s a far cry from 1680, when the City on a Hill was believed to be the largest community in the colonies, a rank it maintained through at least 1740, according to Slayden’s site, or 1790, when Boston was the third largest American city, behind New York and Philadelphia.

Boston proper — not counting the suburbs — has fallen even further on the list of larger cities as it failed to expand its borders as aggressively as some other cities. The latest census data show that it ranked 21st in population, behind cities such as Jacksonville, Fla.; Columbus, Ohio; and Indianapolis, which didn’t even exist when Boston patriots were fighting the Revolutionary War.

While Boston’s metro area has continued to grow, the growth has been slower since 2017. Some of the factors behind the slow-down are typical for places throughout the US, especially in New England: a combination of rising deaths and falling births due to its aging population, said Susan Strate, a senior program manager for the population estimates program at the UMass Donahue Institute in Hadley. But more people also left the state than moved in from other parts of the country, while international immigration has slowed.

If the trend continues, warned Strate, Greater Boston could even see a population decline, something that has not happened since the 1970s, during another period of slow international immigration.

Thomas Vicino, a political science professor at Northeastern University, said while Greater Boston getting bumped from 10th to 11th is a trivial move, the region’s ranking does “highlight some challenges that our region faces” and poses an obvious question: Why is the population growing more rapidly elsewhere? The region, he said, continues to wrestle with familiar and longstanding issues: a high cost of living, a shortage of affordable housing, and — at least before the pandemic — terrible traffic.

“These sorts of issues are bread and butter issues for people when they think about where they’re going to live,” he said.

The three biggest metro areas — New York City, Los Angeles, and Chicago — have remained relatively stagnant in terms of growth in the post-World War II era. Nowadays, more growth is seen in the country’s Sun Belt in places like Dallas and, yes, Phoenix.

“That’s a function of where the jobs are and where people move,” he said.

The good news, he said, is that the Massachusetts capital remains economically competitive and attractive to both people and jobs. The region boasts some of the world’s most renowned universities and research hospitals, along with one of the country’s biggest biotech hubs.

“It’s a moment to reflect on what national trends we see and what we do to keep our region competitive in the future,” Vicino said.