Charter school advocates criticized Wagner's report and proposed moratorium.
The Pennsylvania Coalition of Public Charter Schools called Wagner's report "an attack on Pennsylvania families' right to public-school choice."
Guy Ciarrocchi, the coalition's executive director, said: "In a town known for bad ideas, this is the worst idea of the legislative session."
State Sen. Jeffrey E. Piccola, the Republican chairman of the Senate Education Committee, dismissed the idea of a moratorium.
"I recognize that some in the public-education establishment believe the charter school funding formula is flawed, but we should not punish kids, families, and communities from starting new charter schools over these grievances," said Piccola, who has introduced legislation to overhaul the charter law.
Gov. Rendell, whose administration has favored altering the funding for charters in the past, said that he would review Wagner's report, but that "a flat moratorium is probably not a good idea."
"There is no doubt that some charter schools have been a disaster," said Rendell. ". . . But some produce better results for our students within the framework of our public school system, and I don't think that's something that we can turn our back on."
Wagner stressed in an interview that he was not calling for capping enrollment at existing charter schools.
"We are simply saying there should not be any more new schools" until the flaws are fixed, he added.
As a state senator, Wagner voted for the state's 1997 charter school law. But he called the current funding approach "a bad deal" for taxpayers, with total costs accelerating "at an unaffordable rate."
For example, the state reimburses districts for a portion of their charter costs. That amount has mushroomed from $80 million in 2004-05 to $223 million in 2008-09.
"We can't afford to be wasting precious financial resources on schools whose costs have absolutely no basis whatsoever on what is actually needed to educate children," Wagner said.
Because state law bases the rates paid to charter schools on what the students' home districts spend, there are 500 rates. As a result, districts pay different amounts to educate students attending the same school.
The differences are even more pronounced at the state's 11 cyber charters. The Pennsylvania Virtual Charter School, based in Norristown, provided online instruction to students from 425 school districts in 2008-09. The amounts it was paid varied from $6,753 for students from Mercer County's Grove City Area School District to $15,125 paid by Jenkintown in Montgomery County.
With such variations, Wagner said, some districts wind up subsidizing other students.
He also pointed out that even though it costs less to educate students in cyber schools, the cybers receive the same funding as traditional charter schools.
Wagner called on the legislature to develop a standardized funding system for charters. He urged the state Department of Education to take a more active role in developing that system and in providing charter-school oversight.
He had called for similar changes in 2007.
Contact staff writer Martha Woodall at 215-854-2789 or firstname.lastname@example.org.
Inquirer staff writer Angela Couloumbis contributed to this article.