The Financial Times is not always known as the home of radical research, but now and then it publishes some home truths that have the Tories quaking in their boots.
In a short piece in the FT Data section Chris Cook looked at the myths surrounding grammar schools. To do so he imagined a whole new region called "Selectivia". Despite sounding suspiciously like a "good-bacteria" filled yoghurt drink, Selectivia was a land of unequal opportunities and unhappy children. Cook collated data from the four counties of the UK where the Eleven Plus exam is still most widely taken: Kent, Lincolnshire, Medway and Buckinghamshire.
Of course this region (Selectivia) is extremely well off. Only 8.8 percent of children are eligible for free school meals compared with 22 percent in London and 16 percent in the north west of England. Naturally, therefore, we would expect children in Selectivia to get better results.
But it's not that straightforward. When the FT applied points to every grade that pupils got Selectivia was actually much more divided. Some children did very well, while others did worse than in non-selective areas.
Perhaps it is not so surprising if we consider children are divided at the age of eleven into success and failure. But is this trade off worth it? Does it allow for poorer children to actually do better long term by improving social mobility?
When a new aggregate of the scores was created, one that linked final GCSE scores to poverty, ethnicity, special needs and primary school performance, the results were even worse. This is what has increasingly been known as a "value-added score" within the education system.
The results were astonishing. As a poorer student in Selectivia, you would be better off studying anywhere in London, the south east, south west, north west and east of England - areas which actually all have much higher rates of deprivation.
It wasn't that grammar schools had little effect on social mobility - it was that they had a devastating effect on it. Far from propelling poorer children forwards, they hold them back.
It seems that grammar schools have let the children down, they have let the Tories down, but worst of all they have let themselves down.