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21 March marked the publication of a major review into “the standards of behaviour and internal culture of the Metropolitan Police Service” (that’s the police in London). The author, Baroness Casey, concludes that there is “institutional racism” in the Met, one example of which is that black Londoners are “over-policed”.
As evidence, she cites data showing that black Londoners are much more likely to be subjected to the use of force by police (see below). They comprise around 41% of those subjected to the use of force, despite making up only 14% of London’s population aged 11–61.
But is this evidence of over-policing? The report also includes a section on sexism in the Met, which makes no mention of the fact that men comprise 87% of those subjected to the use of force by police, despite being only half the population. Why no mention?
Well, men commit much more violent crime than women, so they’re much more likely to end up in a situation where the police use force against them. Nobody would seriously claim that men are over-policed because they’re disproportionately represented among those subjected to the use of force.
Casey actually acknowledges that “the entire London population will not be the most accurate baseline to ascertain disproportionality” since children and old people are very unlikely to be subjected to the use of force. Yet she fails to take the argument to its logical conclusion, which is that all groups (not just age-groups) get policed in proportion to the amount of crime they commit.
As Joseph Cesario and colleagues note in a 2018 paper, “insofar as Blacks and Whites have different police exposure rates, a more correct benchmark to calculate racial disparity … is not population proportions but instead rates of police exposure”. And these can be “reasonably approximated by rates of criminal involvement”.
How do London’s ethnic groups compare on “rates of criminal involvement”? Thanks to two freedom of information requests, we know that in the years 2015–2019 and 2021, 56% of those who were “proceeded against for murder offences” in London were black.
This figure represents people whom the authorities felt they had a strong enough case against to pursue legal action, so it’s unlikely to simply reflect bias in who gets arrested. Indeed, Casey criticises the Met for having used the custody population as a benchmark in their own analysis because this “assumes no disproportionality or bias exists in any and all encounters the Met have with the public”.
(Incidentally, the ratio of % black among murder offenders to % black in the population is the same in London as it is in England and Wales as a whole. According to the latest data from the Office for National Statistics, blacks made up 4% of the population but 16% of “convicted principal suspects” in the crime of homicide. 16 to 4 in England and Wales is the same as 56 to 14 in London.)
Recall that 41% of those subjected to the use of force by the Met are black. This means that black people are actually under-represented among those subjected to the use of force – relative to their murder rate. Now, murder rate isn’t necessarily the correct benchmark for assessing whether black Londoners are over-policed, but it’s certainly more appropriate than population aged 11–61.
Which would you say is a better benchmark for assessing whether men are over-policed? The fact that they comprise half the population or the fact that they comprise 96% of those “proceeded against for murder offences”? If Casey wants to insist that population is the right benchmark, she has to accept that male Londoners are massively over-policed.
The Casey Review does not provide convincing evidence that black Londoners are over-policed. This matters because when the police come under pressure not to appear “racist”, ordinary people suffer from the lack of enforcement.
Image: Police at London G20 protests, 2009
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Now the question is if she does understands the math or not? I am often stunned how innumerate people are but in her position you should be able to expect a solid background in statistics.
I think Casey (though seriously overrated as a policy “go to” ), isn’t uninformed. However, the social science academics who i suspect advise her will be driven much more by right-on reputation washing than statistical rigour Casey is chosen because though a thoroughly Blairist and house trained policy bureaucrat, she usually tries to feign having a mind of her own. In this issue as Noah knows to his great professional and personal cost you are just not allowed to reject the dogma of institutional racism as an explanation for any and all disparities.