The Swedish model of schools championed by Education Secretary Michael Gove has not transformed the academic achievement of the country's pupils, a report has suggested.
The biggest beneficiaries tend to be students from highly educated families, rather those from low educated backgrounds, it says.
The paper, published in the latest edition of Research in Public Policy, reviews the evidence on so-called "free schools" in Sweden.
Under the Swedish system, non-profit and for-profit organisations are able to set up and run schools funded with public money, but independent from Government control.
Mr Gove revealed details last week of plans to allow parents' groups, teachers, charities, and voluntary groups to set up and operate schools, which would be taxpayer-funded, and non-fee-paying, but independent from state control.
He has previously highlighted the Swedish model, as well as the charter schools system in the United States, as examples of successful free schools policies.
The report's author, Rebecca Allen, of the Institute of Education, found Sweden's experience of free schools is limited in predicting the impact of similar reforms in England.
It adds: "The evidence on the impact of the reforms suggests that, so far, Swedish pupils do not appear to be harmed by the competition from private schools, but the new schools have not yet transformed educational attainment in Sweden."
The Tories argue free schools will give parents more choice, narrow the achievement gap between rich and poor youngsters and drive up standards across the system because of the element of competition it will create.
So far, more than 700 groups have expressed an interest in setting up a school, it was announced last week.
