Thursday, June 05, 2008

Knife Crime - A Media Feeding Frenzy

So, are you scared yet? If not, you damn well should be. Just a glance across some of the headlines in the newspapers over the past few days should have you scared of leaving your house:

Brown toughens controls on knives after spate of fatal stabbings
Violent crime crackdown: Brown says young people carrying knives must be prosecuted
Teenage knife crime 'is one of biggest threats to London'
Knife crime doubles in 2 years
Police boss Sir Ian Blair calls on parents to tackle Britain's epidemic knife crime

And so it goes, on and on, a feeding frenzy of almost epic proportions. Not surprisingly, this is yet another example of the media and politicians exaggerating the risks and mis-informing the public.

The problem with all of the reports above is use of the statistics to prove their case. The statistics are, as always, not put into proper context and manipulated to make it appear that the problem is worse than it actually is. Take, for example, the following paragraph extracted from The Times:

Of the 820 homicides in 2005 in England and Wales, 236 – or 29% – were with a knife or other sharp instrument. Those figures showed that knives are used in 6% of all violent crimes.

Sounds pretty scary. Twenty-nine percent appears to be a large figure, but what is the reality? Well, the reality is that the national police recorded crime statistics do not differentiate between the various types of weapons used:

It is currently not possible to identify offences involving the use of weapons other than
firearms from national police recorded crime statistics. Figures for serious wounding
involving knives and other sharp instruments from 2007/08 onwards will be presented in
future volumes.

Only offences involving firearms are actually recorded by the national police statistics, the only available information is via the British Crime Survey. So what about the actual statistics regarding violent crime? Well, that is rather interesting.

According to the figures:

Violent crime as measured by the BCS has fallen by 41 per cent since a peak in 1995,
representing over half a million fewer victims.

A decline of 41%. A pretty amazing decline, particularly given the public perception. Furthermore:

The number of violent crimes experienced by adults showed no statistically significant
change between 2005/06 and 2006/07 BCS interviews. Police recorded violence against
the person fell by one per cent between 2005/06 and 2006/07, the first fall in eight years.

So, depending upon what figures you believe, violent crime has either remained static or shown a slight decline. It has most definitely not shown a marked increase. So what of the actual figure? Well, according to the latest figures, there were 2,471,000 violent incidents against adults
in England and Wales in the period 2006/7. The graph below shows the trend over the past 26 years (you may need to click the image to see it clearer):

Furthermore, whilst assaults without injury have increased, assaults with injury or with wounding have either remained static or declined as the following graph demonstrates:

So what about the statistics regarding knife crime? Well, according to the BCS, weapons were used in 24% of 'violent incidents'. Given that violent incidents stand at around 2,471,000, that means that 593,040 involved the use of a weapon. In terms of knives, 7% of 'violent incidents' involved the use of a knife. That means that there were approximately 172,970 'violent incidents' involving knives during 2006/7. What is also interesting, however, is that 'violent incidents' involving a so-called 'hitting implement' (which includes sticks, clubs and 'other hitting implements') was around 6% and incidents involving 'glass/bottles' was around 5%. Strangely, we don't hear many politicians speaking out about the rise in bottle/glass crime, perhaps it's not as catchy. The stats break down as follows (again you may need to click on the image):

It would appear that knives aren't as much of a problem as we are lead to believe. Statistically speaking, you have a 0.2% chance of being involved in a knife crime and, given that 2% of knife incidents lead to minor injuries, an even smaller chance of being injured by someone wielding a knife. Compare the risk of falling victim to knife crime to the risk of having a car crash. In 2006, the police reported 189,000 car accidents that resulted in an injury. The driving population is around 33 million. Statistically speaking, you have a 0.57% chance of being involved in a car accident and suffering an injury. Therefore, you are nearly THREE times as likely to receive an injury in a car crash as you are to be the victim of knife crime. And yet, knife crime is at the top of the news agenda and car accidents barely register. The risk is, quite clearly, exaggerated.

Going back to the earlier paragraph, another aspect of the story becomes clear. The Times reports that 29% of murders involve a knife or 'sharp instrument'. When you think about it logically, this makes perfect sense and is not even slightly disturbing. Guns and knives seem to be the most obvious method of committing murder so clearly the percentage would be higher. When you consider the instances of domestic violence and, in some cases, murder, it is obvious that a knife or sharp implement would be high up the list. What implement do most people have lying around at home? Besides, as the stats show, 236 murders were as a result of the use of a knife. The risk of being murdered by knife is tiny. In fact, it is approximately 0.00039%, a risk so low as to be negligible.

But it's not just The Times that plays with the stats, the BBC mis-represents the figures somewhat as well. Below are two graphs from today's website:

What is interesting about these figures is what they seem to suggest. In the top graph, we can see that murders involving 'sharp implements' has risen by what appears to be a huge amount (around 9-10% apparently). However, when you look at recorded homicides, there has been a slight decrease and this is where it is interesting. The first graph uses a % figure and the second uses an actual total. This has some problems. For example, it could be the case that the total number of homicides has declined (which appears to be the case), and yet the total number of homicides due to 'sharp implements' may have remained static. However, if the number of homicides involving sharp implements had remained static when the overall homicide figure had gone down, there would obviously be an increased % of homicides due to 'sharp implements'. A better indication of the reality would be if a total was provided instead of a percentage, but given that there is a chance that the use of knives has remained static, or possibly increased slightly, this would point out the absurdity of the current media frenzy.

None of this, of course, intends to undermine the hurt and pain that victims and their families feel about knife crime. However, it is sensible to put this in proportion. You are less likely to be involved in an incident with a knife than to be involved in a car accident that results in your injury. Violent crime has declined dramatically over the past ten years. And, if you are involved in a violent incident, you are less likely to receive an injury than you were ten years ago. So, don't be scared, and keep the hype in perspective.

The crime stats referred to above are taken from the official statistics available here.