The introduction of state-funded independent schools has dramatically changed Sweden's education system by stimulating diversity and competition among state schools.
A study that examined the impact of the state independent sector between 1991 and 2004 found that state schools have become more specialised in order to attract pupils.
But the state independents, which inspired Tony Blair's plans for trust schools, have achieved only marginally higher grades than other state schools.
Karin Wahlstrom, who led the study, said: "Schools are now much more competitive. State schools have been forced to profile themselves to compete effectively against the independent sector."
The state independents are run by businesses or community trusts and make money through cost-effective management. They are funded on the basis of the number of pupils they attract and often specialise in IT and technology, music, drama and foreign languages.
State schools have also started to specialise. Kungsholmen, one of the largest upper-secondaries in Stockholm, now specialises in several subjects including English and music.
Deirdre-Cronin Olson, principal of IES Enskede, one of Stockholm's largest independent secondaries, said: "We have an international profile. Like all schools, we are legally required to follow the national curriculum, but we teach mainly in English.
"It is partly the international profile that attracts many parents and pupils. They value the importance of English today."
With state and independent schools both promoting themselves, Ms Wahlstrom believes it is getting harder to talk of two separate sectors.
However, independent schools are mostly in the major cities, leaving parents in rural areas with little choice but to send their children to the local state school.
The study also showed that independent schools have a higher proportion of children from ethnic-minority backgrounds (22 per cent) than state schools (14 per cent).
One parent, whose child attends Engelska Skolan Norr, an independent in central Stockholm, said: "There has always been segregation. In the past, it depended on where you lived. Now we're not bound to the ghettos."
But while Swedes now have a choice, many independents have waiting lists.
IES Enskede has a waiting list of four years.
The study found that pupils at independents achieve marginally higher grades on average than their state-school peers, although the grades are awarded by teachers - often for how hard pupils work rather than actual achievement, so there is a growing debate about their worth.
The emergence of the independent sector has hit some local authorities hard. Those with the highest numbers of independent schools have seen a sharp rise in their costs, mainly because they have had to invest in attracting pupils to their state schools.
There are 560 primary and secondary independents and 240 independent sixth-form colleges, which:
* are run by firms for profit or community trusts
* are state funded on basis of pupil numbers
* cannot charge tuition fees
* must be approved by the National Agency for Education
* cannot hold entrance exams
* must admit students on the basis of first come, first served
* must follow the national curriculum but can specialise.