A little-noticed recent study from the Bloustein School of Planning and Urban Policy at Rutgers University contains what may be a landmark finding: For the first time in three decades, the five boroughs of New York City are reclaiming population, income, and jobs from the suburbs.

For decades following World War II, the city faded and the suburbs flourished. But researchers James W. Hughes and Joseph J. Seneca, in a study titled “The Beginning of the End of Sprawl?” detect the beginnings of a demographic sea change.

“The trend shifted abruptly after 1990,” they write, “when the region’s overall population began to increase at a far more substantial rate. The regional core experienced resurgence, with its population growth rate matching that of the suburban ring. A near half-century long pattern of suburban population growth and urban population decline came to end.”

The authors caution that their conclusions are tentative and may only represent a short-term about-face in the seemingly relentless march to the suburbs. One section is headed “The End of Rampant Suburbanization?” Note the question mark. Yet there are indications that the sprawl and commutes that come packaged with the picket fence have left disen chanted suburbanites looking again toward the city.

One reason for the trend may be that as more urbanites move to the suburbs, they bring along much of what they’d hoped to leave behind in the city: traffic, congestion, noise, high taxes. As the authors of the study report: “Relentless economic sprawl has yielded suburban and exurban crawl and congestion on an enormous scale in the region.”

Rather than taking its good fortune for granted, New York could seek to accelerate the recent gains. How many would-be New Yorkers leave the city behind as tax refugees fleeing the municipal income tax? Imagine how much good the city could do itself with real improvements in its schools or an end to rent control.

New York certainly has room to grow. The most desirable parts of the city have always been those marked by high or growing population density. The struggling sections of the Bronx, for example, have been characterized by declining population density over the past 40 years. For those who yearn for the lawns and backyard barbecues of suburbia, Staten Island and Queens can offer much. If the suburbanites want to come back to the city, plenty of room exists. The city government can help by giving those fleeing the suburbs a clear policy message that they are welcome here.