A bizarre crime statistic

Last week, statistics of pickpocket crimes in the UK were published.  The newspaper seized on one aspect of these, which was the age of the victim.  The headline was that there had been one victim aged 110 years, and two babies of under 12 months.  And, further down the story, was the assertion: "The most likely age to be a victim is 23 years old".

Clearly, the reporter had confused the statistics.  The crime report may have observed that the most frequent age of a pickpocket victim was 23, but that is not the same as being the most likely.  First, pickpockets do not (I guess) ask their victim their age before carrying out the crime.  There is no specific age-dependence on being a victim.  Second, the chance of being a victim depends on one's lifestyle.  People aged 23 are quite likely to have a lifestyle that places them in locations and at times where they may have their pockets picked, compared with older people.  People aged 23 are more likely to carry items attractive to pickpockets than retired people.  So really the data about age is misleading ... and one wonders what response the journalist expected his/her readers to make to the story.

I guess many O.R. practitioners have seen similar cases of statistics being misused; the lesson is to take statistics with a pinch of salt.

"The probability increased steadily until it reached boiling point" one (non-mathematician) lecturer announced.


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