Why ministers make bad decisions

New research into the marked improvements in London’s schools (on which read Stephen Tall’s insights), has this conclusion:

Improvements in London seem more likely to have primarily resulted from changes occurring in the late 1990s and early 2000s, such as the National Strategies.

Or to remove the polite civil servant speak: it’s only 15 or so years after doing something right that we’ve managed to work out just how right it was – though we’re still not quite sure what that something was.

With that sort of long time lapse and uncertainty, making decisions based on evidence is far easier to say than to do.