That could reenergize some local public schools, said Paul Levy, president of the Center City District, which works to improve the climate for living and working in the affluent neighborhood at the heart of Philadelphia.
"If you look forward at the demographic wave that is coming, you've got a lot of opportunity," Levy said.
In the area from Tasker Street to Girard Avenue and between the two rivers, the number of children under 5 has grown 42 percent in the last decade, to 5,287.
Many of those children belong to families that can't afford private school. If more of those parents see their local public schools as an option, they might stay in the city, Levy said. That would help maintain neighborhoods and feed the city's tax base.
He acknowledged the timing of the report was complicated for the School District of Philadelphia because Superintendent Arlene C. Ackerman left on Aug. 22.
New leadership, however, also provides a chance to pursue fresh ideas, Levy said.
He cited the Meredith School in Queen Village as an example of how local parents backed by a strong principal can create a public elementary school with strong academics and a diverse population. About 87 percent of the children in Meredith's neighborhood go to school there.
In addition to the burgeoning population of preschoolers in some neighborhoods, other demographic shifts are in Philadelphia's favor, Levy said. Many parents of young children want to live in a vibrant urban area near museums and restaurants. They enjoy walking or biking to work.
Levy emphasized that the School District still must focus primarily on providing a good education to all students, particularly the vast majority who are poor.
But keeping middle-class families in public schools could broaden "the lobby for improved public education in Philadelphia," the report said.
Even small changes would help, it said.
Many parents try to transfer children from their local public schools to Meredith or Greenfield or a handful of other public schools that are considered better than average.
When he was schools chief, Paul Vallas made sure those parents got word whether their children could switch schools before the adults were required to put down deposits at private schools.
That policy has lapsed, adding uncertainty to families' education decisions. Levy believes reinstating it would ease uncertainty and encourage families to stay.
To guard against gentrification, the report recommends reserving at least 30 percent of each grade for students from outside the schools' catchment areas and outside Center City.
In a statement, Leroy Nunery II, acting school superintendent, said, "The district looks forward to working with CCD and the larger business community to develop solutions, gather resources, and affirm relationships that will ultimately benefit all Philadelphia schoolchildren."
Levy said he was hopeful more schools could be like Meredith.
"No parent, no family, should be beating their heads against a wall," he said.
Contact staff writer Miriam Hill at 215-854-5520, email@example.com, or @miriamhill on Twitter.
Inquirer staff writer Troy Graham contributed to this article.