Is crime data important?

Have you ever stopped to think how important crime figures might be and perhaps wondered that what you’ve just been told by those ‘in charge’ doesn’t seem to add up?  Well, just to prove that you’re not losing it here’s part of an article I just found on The Oakland Tribune’s website pages (California) written by Daniel J. Willis.

Oakland city officials have once again proved that their definition of "90 percent" is "an unknown percentage between 0 and 100, but probably not 90."

Police Chief Howard Jordan said Monday that 90 percent of the city's crime since summer had been committed by just two gangs. That would have meant those two gangs were responsible for 1,980 robberies and 51 homicides, which would have required them to be either extremely large or extremely efficient.

Those figures, of course, did not last long. By the end of Tuesday, Jordan claimed that he got confused -- which raises its own set of issues about a police chief who gets confused and makes up numbers at a news conference -- and what he meant was that 14 gangs were responsible for 65 percent of 58 percent of homicides....

.....By itself this would be bad but it's the second appearance of the imaginary 90 percent in the city's recent history. Mayor Jean Quan's 100 Blocks program was originally based on the premise that, according to the mayor, 90 percent of crime occurred in 100 blocks of Oakland. The real number turned out to be 17 percent.....[you can read the rest here]

If you think this sort of cock up is rare then think again.  Politicians and Police Chiefs around the world and through time have continuously got crime data wrong, usually through carelessness and genuine mistake, but sometimes you can’t help wondering if there was more to it.   

There are literally hundreds of examples on the net and here’s just a few of the more recent, which are fun to read and watch:

2012 USA  READ Is there pressure on the police not to record crime or deter victims from reporting?

2012 UNITED KINGDOM  READ When the data is inputted incorrectly

2011 USA WATCH Political pressures

2011 UNITED KINGDOM READ Well meaning Home Office service gets the data wrong with unforeseen consequences

2010 UNITED KINGDOM READ When recording standards change and are not taken into account

2010 SOUTH AFRICA READ When miscalculations exaggerate a fall in crime

2010 CANADA WATCH  Politician not sufficiently briefed and makes it up

And be wary of our own measures of crime in the UK.  You’ve got two sets of figures; the Police Recorded Crime and the Crime Survey for England and Wales (Previously called the British Crime Survey (BCS)).  Scotland and Northern Ireland publish their own data separately.

The police crime data is a measure of crime reported to and recorded by the police and obviously not all of it gets reported or recorded for lots of reasons.  The ‘more trusted’ Crime Survey for England and Wales (when know as the BCS) was severely criticised in this 2007 press release from Loughborough University by Professors Graham Farrell and Ken Pease in which they estimated that the survey was underestimating crime by as many as 3 million incidents a year.

So, my advice is to be sceptic, don’t take quotes for crime data on face value and ask your politicians and those in charge of policing where they got their data from

You know it makes sense!