An interesting claim I found in the press: there is some concern because GCSE grades in England this year were lower than last year. What caused this?

One reason for the weaker than expected results was the higher number of younger students taking GCSE papers. The JCQ figures showed a 39% increase in the number of GCSE exams taken by those aged 15 or younger, for a total of 806,000.

This effect could be seen in English, with a 42% increase in entries from those younger than 16. While results for 16-year-olds remained stable, JCQ said the decline in top grades “can, therefore, be explained by younger students not performing as strongly as 16-year-olds”.

Newspapers seem to get worried whenever there are educational results out that there might be some dreadful societal decline going on, and that any change in educational outcomes might be a predictor of the impending collapse of civilisation. This alternative explanation of reduced age is therefore quite interesting, I thought it would be worth trying to analyse it formally to see if it stands up.