“Charter School Performance in Los Angeles,” a report from Stanford’s Center for Research on Education Outcomes (CREDO), found that a student in an urban LA charter gains 50 more days of learning in reading and 79 more days of learning in math, compared with a peer in a traditional district school.

In suburban LA charters, the report said a student gains about 65 more days in reading and 101 additional days in math.

The results were especially significant for low-income Hispanic students in charter schools, according to the report’s co-author, Dev Davis.

“The gains for Hispanic students in poverty at charters amount to 58 additional days of learning in reading and 115 more days in math compared to their district school counterparts,” he said in announcing the study.

The report is based on data from 2008-2009 to 2011-2012 from the California Department of Education. Currently, LA Unified has jurisdiction over 248 charter schools  — 52 affiliated and 196 independent — serving over 136,000 students in kindergarten through 12th grade.

In an email to members of the LA Unified board and senior staff at the district, Superintendent John Deasy said of the report: “It is high affirmative of the LAUSD in how we approve, monitor, intervene, and close charter schools. We have the highest performing charter portfolio in the nation.”

Later, in a statement from the district, Deasy said: “Today’s study is another indicator of the amazing results our students, educators, and parents are accomplishing in Los Angeles. The students in both District and charter schools in Los Angeles are achieving at the highest levels in the history of the city.”

Analyzing schools overall, the study found relatively positive developments for charter schools. In reading citywide, 48 percent of charter schools have significantly larger learning gains, compared with traditional alternatives, while 39 percent were judged to have no significant difference and 13 percent of the charters performed significantly worse.

In math, 44 percent did significantly better, 34 percent were about the same as their peer traditional schools and 22 percent of the charters were significantly worse.

Those results compare favorably with CREDO’s 2013 national study of charters, which found that 25 had significantly larger learning gains in reading and 29 percent had them in math. Nineteen percent of charter schools had results that were significantly worse than their district school peers in reading and 31 percent were inferior in math.

* This update expands on Deasy’s comments.