John Reid, the previous UK home secretary, said in 2006 that his department was “not fit for purpose”. That certainly still seems to be the case for the department’s crime statistics, which had dramatically misreported some categories of crime. Bad statistics encourage bad policy, but they also promote the pernicious idea that neither statistics nor politicians are to be trusted.

A number of police forces across the UK had, until this year, been making an error in which category they filed some types of violent crime within their data tables. Correcting this has driven a 22 per cent surge in incidents in the most serious category of violent crime. These events were always counted and investigated, but they were simply filed in a less violent crime column. A purely statistical mistake, but a serious one, nonetheless.