Pupils attending schools that provide sixth-form education are not necessarily more likely to achieve better exam grades than those enrolled at schools without a sixth form.
This is according to a new report from the educational data analysis organisation SchoolDash, which analysed performance data from 3,118 mainstream state secondary schools in England, of which 68.5 per cent had a sixth form.
On average, secondary schools with sixth forms were shown to obtain better GCSE results than those without, but this may be because these schools tend to attract more able, affluent pupils, as well as being are more likely to be selective.
Once these and other potentially confounding factors were taken into account, SchoolDash's data revealed little difference in GCSE performance between schools that have a sixth form and those that do not.
However, the report also indicated that post-GCSE destinations tended to differ significantly between these two types of school, as pupils at schools with a sixth form were much more likely to continue their education at the same school or elsewhere, as well as being correspondingly less likely to enter a further education college.
This effect persisted even after controlling for other factors, with the analysis suggesting that providing a sixth form in every secondary school could result in up to 20,000 more pupils each year choosing this route over a further education college. Conversely, separating all sixth forms from secondary schools would result in up to 50,000 more pupils every year attending further education colleges.
SchoolDash founder Timo Hannay said: "Whether a pupil goes to a secondary school with or without a sixth form is, in itself, unlikely to affect their GCSE grades. But it may well influence whether their subsequent education is primarily an academic or a vocational one. In short, institutional structures matter, though not always for the reasons that people assume."