Students who go to charter high schools in Chicago score higher on tests, are more likely to enroll in  in “very selective” four-year colleges, and persist longer in colleges than similar peers, according to a University of Chicago Consortium on School Research study released late Monday.

The study comes as competition likely will increase between traditional district-run public high schools and privately-run, publicly-funded Chicago charter schools.

For the first time this year, eighth graders are applying to high school through a common application that includes both charter schools and regular high schools. Each student can match at only one school, putting pressure on schools to ensure students rank them number one.

This new study gives charter schools the edge.

On average, the study finds that 45 percent of charter graduates go to four-year colleges compared to 26 percent of non-charter graduates. And 7 percent of charter students enrolled in “very selective” colleges, compared to only 2 percent of students who attended traditional Chicago public schools. The UChicago study compared students with similar academic profiles as they entered high school.

• RELATED STORY

Charter Schools Hired 163 CPS Staffers Banned For Misconduct, Including Sexual Abuse

read more

However, CPS Chief Education Officer Janice Jackson notes that the study compared charter school and non-charter school students from 2010 to 2013. Since then, district-run schools have copied many of the practices used at charter high schools, she said.

Jackson said she hopes the study doesn’t turn parents and students away from neighborhood high schools, which have been steadily losing enrollment in recent years.

“What is more helpful is looking at schools that work, and replicating that throughout the district,” Jackson said.

Neither charters nor neighborhood schools use admissions requirements to admit students, though charters accept students through a lottery and neighborhood schools must accept all children within their attendance boundary.

While the study might appear to be good news for all charter schools, there’s an important caveat, said the study’s author, Julia Gwynne. She found a surprisingly wide variation between charter schools.

A set of charter schools produced much stronger results than non-charter public schools with students of similar academic backgrounds. But another group of charter schools produced results that mirror or are worse than traditional CPS schools, the study found.

“The key takeaway from the fact that there is so much variation,” Gwynne said, “is that if you are a parent, you have to figure out what is happening at that individual school.”

In other words, school quality matters more than school type, Gwynne said.

The study does not identify any charter schools by name because the study is meant to point out broad differences rather than be used to pinpoint specific schools, she said.

The study also found higher transfer rates at charter schools. About 30 percent of the students who start at charter schools transfer before they graduate, compared to about 18 percent for similar students at non-charter, district-run high schools.

Gwynne said the study can’t offer a definitive explanation for the higher transfer rate. But some parents and advocates have accused charter schools of counseling out low performers or students with behavior problems.

Gwynne said this could be the case, but she noted that some high-performing charter school students also transfer. She said this may occur simply because parents and students in charter schools are more comfortable exercising choice.

The study also offers some explanations for why charter schools may be more successful. Eighth graders attending charter high schools post similar test scores and grades as students choosing district-run schools.

But, on average, the students who chose charters have higher eighth grade attendance.

And once they enroll in a charter high school, the students report markedly different experiences than their counterparts, Gwynne said.

“They report that classes are more demanding,” Gwynne said. “They also reported that their school is more likely to prepare them for the future.”

Gwynne said that these reports, which come from an annual survey of teachers and students, could help explain why charter schools are more successful at getting students into selective colleges and why they persist in college longer. But she said more investigation is needed to provide a definitive answer.

Sarah Karp covers education for WBEZ. Follow her @WBEZeducation and @sskedreporter.