Strict bans on mobile phones in schools have “close to zero” impact on student learning and show no evidence of improvements in attendance or online bullying, a study has found.

Researchers at US universities including Stanford and Duke looked at nearly 1,800 US schools where students’ phones were kept in locked pouches and found little or no differences in outcomes compared with similar schools without strict bans.

The report concluded that among schools instituting a ban: “For academic achievement, average effects on test scores are consistently close to zero.”

The results will come as a disappointment to teaching unions and campaigners in England who backed the government’s recent move to restrict the use of mobile phones in schools. A ban is likely to come into force next year.