To the Editor:

Re “Strike Throws Cold Water on a City’s Embrace of Charter Schools” (front page, Jan. 29): The League of Women Voters of Fresno has completed a two-year study of the 17 charter schools in Fresno. We found that parents and students were happy with their schools. But the data we studied and the visits we made to the school sites revealed a somewhat different story.

With the e xception of two special schools, which have a disproportionate number of white students in a region where the Latino population is more than 50 percent and the Southeast Asian population is about 20 percent, the other charters have math and English test scores below those in the Fresno public school system.

Low graduation rates and high dropout rates were especially pronounced in the independent-study charter schools . They enroll about 50 percent of charter students. The 17 charter schools in Fresno received more th an $65 million in state revenue in 2016-1 7.

There is not enough oversight of charter schools to hold them accountable for these deficiencies and to make decisions regarding which ones should be reauthorized.