Aaronovitch Watch reflects upon dinner with Denis MacShane. There's an important point here, and one that was well made as a by-product of Nick Davies' brilliant reporting on Operation PENTAMETER 2, a giant police sweep looking for prostitutes brought into the UK by force that failed to find even one. It turned out that the entire project was driven by policy-based evidence - a succession of politicos and thinktanks progressively taking what had once been the upper bound in an actual study, treating it as an actual forecast, and then adding a bit.
Not so long ago, I had the opportunity of discussing this with a source in the Met vice squad, and the take-home message is Davies was being conservative - it was actually worse than that.
Anyway, one of the most egregious examples of PBE in the story was the fault of none other than MacShane, who promptly responded by writing to the Guardian and accusing Davies of "taking the side of the managers of the sex industry". As Davies pointed out in the original story, the whole thing followed the pattern of the campaign for war with Iraq with uncanny accuracy.
There was the exaggeration by stripping out caveats, the practice of using deliberately extreme limiting cases as central forecasts, the search for anyone who would provide the right kind of intelligence when the intelligence services' intelligence didn't fit around the policy...and the shameless red-baiting attacks on anyone who disagreed. Sniff, sniff. Are you a good anti-Fascist? Will you condemn, etc, etc?
The lesson, however, is that some people seem to gravitate to this set of tactics or political style (because that's what it is); if Denis MacShane worked for the Party of Kittens, he'd be secretly briefing the press that Mickey Mouse was part of a decadent Hollywood-liberal elite in league with feline leukaemia, based on his summary of a leaked report from the newly established Council for a Flea-Free Future, and if you called him out on it, he'd get all the members of the Accuracy in Cat-Related Media mailing list to write and accuse you of being objectively pro-dog.
Come to think of it, it's part of the package of modern thinking; you need a Boris Johnson-esque clown figure, a Tony Blair-esque tebbly tebbly concerned type, and a MacShane-esque underhand thug.