Bahram Bekhradnia: A case of flying pigs and impossible targets...

Although there have been mixed messages about this - the Labour manifesto repeated the target, but others have spoken of "working towards 50 per cent" - even the more modest aspiration may be unduly optimistic. There has been little sign in the last three years of any progress towards this, and at the rate we are going, no reason to think that there will be. The Higher Education Participation Index has stuck at around 43 per cent over the past three years.

One has to sympathise with the Government, but there is a lesson here: governments cannot really do much directly to influence the achievement of any particular number of students. That relies on the decisions of individual young people about whether to stay on at school and take A-levels and then about whether to go to university.

That is why long-term measures are needed, such as the Aimhigher programme, which was the subject of an encouraging evaluation report last week. Higher education participation is not something that is susceptible to quick fixes in response to government targets.

Today's report looks mainly at two things - demography and examination (mainly A-level) achievement at school. Changes in the size of the population do not affect the proportion of young people going to university, but do affect the total number of places that will be required. (It is worth noting, in passing, the extraordinary fact that the official projection of 18-20 year-olds keeps changing: the growth in this number has reduced by 16 per cent in two years since we first looked at this, despite the fact that the young people concerned were born some time ago.) But it is changes in the proportion staying on at school post-GCSE, and in the number taking A-levels, that make the real difference. Here the story is rather disappointing.

When we first produced a projection of demand for higher education two years ago, there had been a recent sharp increase in the proportion of pupils taking A-levels, following the 18+ examination reforms, and we speculated then that if this increase was the beginning of a trend that could presage a large increase in demand for higher education by the end of the decade. In that case, we would get close to the Government's target. In fact, it looks as though that increase may have been a one-off, and in the two years following there has been no increase in A-level take-up by school pupils.

Nor has there been any increase in participation by older age-groups to compensate (and as 70 per cent of entrants to higher education are full-time school leavers, it would take a truly massive increase by other age groups to compensate for any shortfall here), nor in part-time, sub-degree or any other groups that might make up the shortfall. And there has not been the sort of improvement in GCSE achievement to suggest that we are about to see a large increase in A-levels - indeed, if anything the growth rate of GCSEs has also slowed.

However, when the raw figures are looked at more closely, the reason for stagnating participation is apparent: the well-documented gender divide is having a clear effect. The proportion of 18 to 30-year-old girls in higher education increased from 43 to 47 per cent over the last four years, whereas the proportion of boys showed no increase at all. In fact, it declined last year. And the proportion of girls with two A-levels increased from 23 per cent in 1992 to 39 per cent in 2004; whereas the proportion of boys increased from 20 per cent to just 30 per cent. Whereas in 1992 girls were 16 per cent more likely than boys to take A-levels, the difference had increased to nearly 30 per cent by 2004.

The under-achievement of boys is a real problem - not just for higher education but for society as a whole. But it certainly presents a problem for projecting higher education numbers. Unless boys are inherently more stupid than girls - which they probably are not - there is no reason in the long-term why boys should not participate at the same rate as girls; and when they begin to do so, then perhaps we will start to get closer to the Government's targets. The trouble, of course, is that we do not know when that will be.

Meanwhile, we have to do the best we can with the information that we have. And for the time being, we have to conclude that there is no sign of increasing higher education demand. On the contrary, all the lead indicators suggest the opposite.

The writer is director of the Higher Education Policy Institute

education@independent.co.uk