Knife crime stats fracas

Knife-carrying down in 'hotspots'
Stop and search blitz cuts knife attacks
Crime falls in knife crackdown areas
UK knife crackdown leads to fall in stabbings

These were the headlines of some major news sources the day before the head of the UK Statistics Authority said the figures were irregular.

Many journalists reproduce statistics unchallenged. The same reporters would never publish information in other forms without checking its veracity. The UK government knows this and so has increasingly used figures to spin a story, knowing it is less likely they will be challenged (certainly by the press).

I suspect that some would blame the modern publishing environment which does not leave us time to check source material as rigorously as we would like. But the truth is most journalists hate mathematics; are scared of mathematics.

But checking stats is part of the job: we cannot rely on the head of the UK Statistics Authority always to be on hand. So here are a couple of simple pointers that would have prevented the knife crime story being taken at face value:
  • Never accept information where the full statistics are not made available to you
  • Be particularly suspicious of data that concentrates on hotspots.
See also How Sources, Reporters View Math Errors in News