The estimates by DVRPC staff, compiled with county planners, will not be the agency's official projections until they are approved by the DVRPC board Jan. 26.
The latest projections suggest the Philadelphia region will continue to grow more slowly than the nation, whose population is projected to grow 31 percent over the same period.
The Philadelphia region's population in 2040 is likely to be older and more diverse than it is today, planners say. The increasing number of elderly residents will require better transit and more health-care services.
The region's suburbs will continue to grow, but the long, post-World War II population drain from Philadelphia and inner-ring suburbs is likely to reverse, said Mike Boyer, manager of long-range planning for DVRPC.
Philadelphia is predicted to grow by 105,000 people to 1.63 million, a 7 percent increase.
"We're taking a bullish position" on the city's future, said Gary J. Jastrzab, executive director of the Philadelphia City Planning Commission.
He said the city's population of Asian and Hispanic residents is likely to increase, and he predicted population growth would be especially robust in North Philadelphia neighborhoods near Temple University and along the central Delaware River waterfront. He said Fishtown, Northern Liberties, East Kensington, and parts of South Philadelphia are likely to grow faster than the city as a whole.
Boyer said Philadelphia is likely to continue to see an influx of young adults. To offset the city's long-term pattern of losing young families to the suburbs, the city will need to focus on improving education and safety, he said.
The biggest growth areas in the city are projected to be the central core, which is expected to grow by nearly 20,000 residents (17 percent), and lower North Philadelphia, expected to grow by about 17,000 residents (18 percent). Lower South Philadelphia, around the Navy Yard and the sports complex, is projected to add nearly 2,000 residents, for a 36 percent increase.
Many older suburbs, like Malvern (projected for a 22 percent increase), will also see their populations grow, Boyer said.
Chester County is predicted to get almost 150,000 more residents, an increase of 30 percent over its current population of 500,000. Gloucester County is projected to gain 87,830 residents, a 31 percent increase over its current population of 288,000.
Among other area counties, the DVRPC projections are:
Bucks. 727,000 population, a 16 percent increase (102,000 more people).
Burlington. 495,000 population, a 10 percent increase (46,000 more people).
Camden. 528,000 population, a 3 percent increase (14,600 more people).
Delaware. 570,000 population, a 2 percent increase (11,000 more people).
Mercer. 391,000 population, a 7 percent increase (24,000 more people).
Montgomery. 894,000 population, a 12 percent increase (95,000 more people).
The population forecast assumes a higher migration of senior citizens to Bucks County, and declining overall birthrates but higher fertility rates among women over 35.
The recent economic downturn is likely to suppress population growth until about 2015, when forecasters expect the rate of growth to increase. By about 2035, the rate of growth will level off, the forecast suggests.
Among the region's towns, the biggest gainer is projected to be Woolwich Township in Gloucester County, which is expected to grow to 23,000 residents from the current 10,200, an increase of 126 percent.
The biggest loser is projected to be Trainer Borough in Delaware County, which is predicted to shrink from its current 1,828 people to 1,727, a decrease of 5.5 percent.
One place is predicted to be unchanged by the passage of time.
The region's smallest town, Tavistock Borough in Camden County, which consists of three houses, a golf course, and a country club, is projected to have five residents in 2040 - the same as now.
Contact staff writer Paul Nussbaum at 215-854-4587 or email@example.com.