A former Labour Education Secretary, Estelle Morris, once spoke about the "gold standard" of A-levels.
The point of gold standards is that they should not be able to lose their value. But the uncomfortable truth is that A-level standards have steadily eroded. Two decades ago, only two thirds of pupils passed them. Today, everyone does. This year 96.9 per cent of students gained an A-E grade.
It's hard to believe that this startling improvement is because pupils are doing so much better. Academic evidence shows that the standards of A-levels themselves have become steadily easier.
For example, a student achieving an E grade in A-level maths in 1988 would have achieved a B in 2004. GCSEs and the National Tests for 11 year-olds have also become easier.
Employers and universities all complain that the standards are falling, and the public agree.
Ministers reject this evidence, but they also send mixed signals about A-levels. Their plans for an A* grade were an implicit concession that grade inflation had happened.
The Government rejected a review which called for A-levels and GCSEs to be subsumed within a new diploma. But this week the Schools Secretary, Ed Balls, announced diplomas in three academic subject areas - science, languages and humanities - in addition to the 14 planned vocational subjects.
Diplomas were meant to improve vocational education. Mr Balls said that he wouldn't "pre-judge" whether A-levels would be abolished, but admitted that diplomas could become "the qualification of choice for young people".
It was pretty obvious that he had come not to praise A-levels but to bury them. Once again the "gold standard" has been devalued.
I know that talking about grade inflation is a tough message for teachers and pupils who have worked hard and are understandably proud of their achievements. But at the end of the day, it really is in everyone's interest to maintain exam standards.