Original paper headline: Small sixth forms are AS liability, study finds
A typical AS-level at the smallest school sixth forms costs pound;100 more and will earn a points score nearly a third lower than one in a college, according to research by the Association of Colleges (AoC).
In an analysis intended to cast doubt on the sixth-form presumption that has allowed schools to expand into post-16 education even where demand is low, the AoC found that the larger the sixth form, the better - even though colleges with some of the largest numbers receive about 10 per cent less funding per qualification.
It costs about pound;1,000 to provide an AS-level at a college and pound;1,100 at a school.
No college has fewer than 350 post-16 students and the average points score is 795 under the Qualifications and Curriculum Development Agency's tariff, in which an A is worth 270 points.
The smallest sixth forms, with fewer than 50 students, achieve an average of 561 points, slightly less than the difference between two A grades and two Es. Even those with up to 150 students suffer a penalty almost equivalent to one E grade instead of an A.
But large school sixth forms are likely to do just as well or better than colleges - the average points score for all institutions with more than 250 students taking A levels or equivalents is 802.
Martin Doel, chief executive of the AoC, said sixth-form colleges were also more likely to preserve core academic subjects because of their size.
"The poor performance of smaller school sixth forms is a source of concern as it raises serious doubts about continued political support for an increase in their numbers," he said.
"New smaller school sixth forms do not look like an efficient investment according to this data."