Talking of affluent Shetland, it can never be accused of having leafy suburbs - or, indeed, leafy anything. But perhaps another report out last week explains why it is such a good exam performer: the statistics on local authority costs show it spends 80 per cent more on educating secondary pupils in Shetland than the Scottish average (page four).
Bill Manson, the island council's education spokesman, made the usual noises about how inevitably expensive this is in areas with a lot of small, remote schools.
But how to explain the conundrum that it costs less to educate secondary pupils in Orkney? "Orkney is a more nuclear sort of island," Manson suggested mysteriously.