A chart from a 2010 analysis that compared charter schools' performance by authorizer.

When a researcher with a penchant for crunching charter school data sat down to compare New York State’s charter authorizers in 2010, her impetus wasn’t merely academic.

For Jonas Chartock, then the director of one of three authorizers, who requested an analysis, the data was a matter of survival.

“At the time there was a real push by some politicians to eliminate SUNY as an authorizer,” said Chartock, who headed SUNY’s Charter School Institute until early 2011.

Chartock asked Macke Raymond, a Stanford researcher who had just wrapped up a broad study of New York City’s charter sector, to examine her school performance data based on which office had authorized it. Her comparison showed up as an attachment to one of several hundred Department of Education emails released last week in response to a teachers union’s Freedom of Information Law request.

Raymond found that students at SUNY-authorized charter schools improved at a quicker pace than students at schools authorized by the State Education Department and the city Department of Education. At schools authorized by SED, she found, students actually lost ground over time.

At the time, the Board of Regents, which decides which schools get SED approval, was attempting also to strip SUNY of its authorizing power and give itself more control over which schools are allowed to open. Under the Regents’ previous leadership, the board had symbolically rejected about 70 percent of SUNY’s charter approvals between 2007 and 2009.

Led by Chancellor Merryl Tisch, the Regents’ power grab took place at a time when charter school advocates were pushing legislation to allow more charters to be handed out. If SUNY exited the scene, they feared, fewer charter schools would open.

In the end, after a bruising legislative session, SUNY retained its authorizing responsibilities, but legislators stripped the city of its authorizing rights.

The data turned up in redacted emails circulated between Chartock and Michael Duffy, who headed the city education department’s charter school office at the time.

The authorizer comparison analysis was limited and is now years out of date. While more than 30 SUNY-authorized elementary and middle charter schools were open during the years covered in Raymond’s data, just five schools authorized by SED were open during that time.

The state’s education department has since bolstered its charter school office. It brought on new leadership and has now issued charters to a total of 44 schools, including 11 that are set to open in the next two years. SED officials did not respond to requests for comment but SUNY’s interim director, Susan Miller Barker, said the relationship between the two authorizing bodies had become “much more partnership-focused than in the past.”

Alex Medler, a Vice President at the National Association of Charter School Authorizers, which pushes authorizers to follow a common set of guidelines when authorizing charter schools, said that New York State’s authorizers were among the highest quality in the country.

“Based on the strength of both authorizers’ work, I would note that is not appropriate to use the sort of analysis offered … to justify any head-to-head comparison of those two authorizing shops today,” Medler said.

James Merriman, CEO of the New York City Charter School Center, agreed that it would be wrong to make basic conclusions based on Raymond’s data and said the topic required a more extensive look. A recent analysis of the city’s charter sector conducted by the center did not compare schools by authorizer.

But Chartock, who left SUNY in 2011, said the data report served its purpose, which was to convince lawmakers that SUNY should remain as an authorizing body.

“Essentially, those data allowed us to show the strong work of the Charter School Institute over the course of its authorizing history,” Chartock said.

CREDO Data by Authorizer