“Everyone’s pencil should be on the apple in the tally-mark chart!” shouts a teacher to her class of pupils at Harvest Preparatory School in Minneapolis. Papers and feet are shuffled; a test is coming. Each class is examined once every six or seven weeks. The teachers are monitored too. As a result, Harvest Prep outperformed every city school district in Minnesota in maths last year. It is also a ‘charter’ school; and all the children are black.
Twenty years ago, Minnesota became the first American state to pass charter school (publicly funded but independently managed) laws. The idea was born of frustration with traditional publicly funded schools and the persistent achievement gap between poor minority pupils and those from middle-income homes. Charters enroll more poor, black and Latino pupils, and more pupils who at first do less well in standardised tests, than their traditional counterparts.

Today there are 5,600 charter schools serving more than 2 million pupils in 41 of America’s 50 states. This number has grown annually by 7.5 percent since 2006 but is still tiny: charters enroll less than 4 percent of the country’s public-school students. Some places have taken to charter schools enthusiastically: in Washington, DC, 44 percent of public school students attend a charter school.

Parents like charter schools, and waiting lists for them are growing faster than new places. Nina Rees, the new head of the National Alliance for Public Charter Schools, says more than 600,000 children are on waiting lists. Oversubscribed schools choose pupils by lottery, as is poignantly illustrated in the documentary film Waiting for Superman.

Critics of charter schools derive more ammunition from the fact that their performance varies widely. For example, earlier this year the University of Minnesota found that charters in the twin cities of Minneapolis-St. Paul lagged behind public elementary schools, ranking 7.5 percent lower for maths and 4.4 percent lower for reading.

Hundreds of other studies have been done on charters, but most are of dubious quality. One recent analysis had to discard 75 percent of its research because it had failed to account for differences between the backgrounds and academic histories of pupils attending the schools. Much political capital has been made of a 2009 study of 16 states which found only 17 percent of charter schools were better than public schools, 37 percent were worse and the rest were about the same. The work was done by the Centre for Research on Education Outcomes (Credo) at Stanford University.

Nevertheless charter schools have been successful because they offer freedom to shape schools to pupils, rather than the other way round. Schools can change the length of the school day, fire bad teachers and spend their money as they wish. At Harvest Prep the school year is continuous, with short and relatively frequent bursts of holidays, because that keeps learning on track and kids out of trouble.

(Excerpted and adapted from The Economist)