The annual ritual about A-level results pits ministers and teachers who insist that increasing pass rates reflect well on the system against their critics, some of whom believe that the merit of any examination can only be measured in proportion to the number of people who fail it. Both are misguided. It is a positive development that many more young people are sitting A levels, passing them and securing impressive grades than was the case ten, twenty and, especially, thirty years ago. Higher education, for which the A level is the gatekeeper, was once the preserve of an elite few, with an intake restricted in the manner of a medieval guild. It is right that many more individuals with the talent to undertake a degree course have the opportunity to do that. Kingsley Amis was not correct. More does not inherently have to mean worse.

A crucial function of any public examination, however, is to offer a clear indication of the comparative performance and potential of those who pass it. More than a quarter of all grades now being awarded are A’s, and therefore it cannot possibly be argued that the A level manages to identify the most talented. The top mark covers far too broad a range from the very good to the absolutely exceptional. It is hard for universities, employers or society at large to distinguish between these people. This year slightly more than 9 per cent of all students – 30,000 of the candidates – sitting A levels achieved three A grades (more in some instances). That is in excess of twice the total of the available places this year at the top five institutions listed in The Times Good University Guide.

The response of the Government is to point out that a new A* grade will soon be introduced and this will help to make distinctions between the brightest students. For a short time it plainly will but the relief will be probably prove merely temporary. The present plans of the Joint Council for Qualifications are that a pass mark of, for example, 85 per cent in a subject would be rewarded by the new grade. Over time, though, experience indicates that the percentage of students reaching that standard will rise and the problem of identifying the most talented ones will resurface.

It would be far better, therefore, simply to award the A* accolade to the top 5 per cent of candidates in each subject. Any claim that this would be administratively difficult is undermined because a similar method was used in the earlier days of the A level when there were many more examination boards than today. Ministers must not allow dubious bureaucratic objections to stand in the way of credible reform.

They should also be profoundly concerned at the pattern revealed by the current A-level statistics. The rise in A grades is not uniform but is concentrated in the independent sector and the small minority of state schools that are overtly selective. The mainstream state sector, by contrast, is making much more modest progress. If this continues, the temptation for the middle classes to go private for the A-level years (if not completely) will become compelling. While money spent per pupil in these schools must be a factor in their success, it is not the sole explanation. The intensity of focus on examinations is a major element as well. Some will react to this emerging divide by searching for means of holding back students from selective backgrounds. They would be better advised to seek out ways of exporting their ethos to the state sector.