Journalists nearly always find a retired examiner who is willing to babble on about “grade inflation”. Editorials duly thunder and MPs duly bluster. Examining boards explain that a lower pass mark will not imply lower standards if the questions are harder. Nobody - least of all journalists who are almost all innumerate - understands this point. The month normally concludes with the announcement of an “inquiry”, by which is meant that some exam board functionary will browse through old exam papers before reporting that he can find “no evidence” of declining standards.

Well of course he can’t find any evidence. Unless we are talking about something very straightforward like the driving test or Who Wants to be a Millionaire?, standards are inscrutable, because both syllabuses and examining methods change. Suppose we reduce algebra in A-level maths and increase geometry. Can anyone sensibly compare the “difficulty” of the new geometry questions against the old algebra questions?

I think it likely that standards have declined, that it is easier now to get an A-level than it was 30 years ago. There are simply too many pressures - from teachers, parents, politicians - for the exam boards to resist. In any case, exam boards are in competition. If one sets papers that are marginally harder than the others, it will lose business. If the boards were run by Daleks, or some other form of robotic intelligence, it might be otherwise. But as long as our exams are subject to human control (unlike American tests, which are marked by machines), human nature will prevail.

There is a larger issue. Exam standards rise and fall according to the numbers we want to pass, not according to objective criteria. This was the case with the 11-plus, for which pass rates varied capriciously, according to the availability of grammar school places in different areas of the country. I do not recall protests from those who now pose as the guardians of standards.

We used to pass barely half the entrants to A-level, who were drawn from a very small proportion of the population. This was because university places were severely rationed; so were places in such professions as accountancy and law. The A-level system acted as a rationing device, rather like the points in the post-war rationing books of my childhood. I got more sweets on ration in 1952 than I got in 1948 but I did not conclude that the standard of sweets had somehow fallen.

It is the same with A-levels. It is perfectly possible that the young people who now take them are brighter than their predecessors. But that is not why we give more of them pass marks and A grades. We do so because we want more people to go into higher education, an aim that, save for a few curmudgeons like the late Kingsley Amis and the dearly-departed Chris Woodhead, enjoys nationwide approval. In this respect, it was felt, we had to compete with our European rivals, to say nothing of America and Japan.

One solution was to lower university entry standards. We did the opposite: we raised entry standards for people like trainee teachers who now need two A-levels where they had previously required only one.

A-levels sort out the top 30 or 40 per cent who should go on to higher education and, within that, the top 5 or 10 per cent who should go to elite universities. If we decide that 60 per cent should go to university, the pass rates will rise accordingly. If we decide that everybody should go to university, we shall abolish A-levels, as we abolished the 11-plus when we decided that everybody should have a decent secondary education.

Peter Wilby is editor of the ‘New Statesman’