Tuesday, April 07, 2009

Violence down?

According to Simon Collins at the New Zealand Herald;

New Zealand's murder rate appears to have almost halved in the past 20 years despite an overwhelming public belief that crime has got worse....The murder rate is regarded as one of the best measures of trends in actual violent crime, because it is least likely to be affected by changing police policies or public attitudes which are believed to have affected recent family violence statistics.

Collins is basing his observation on police statistics. He continues;

The rate leapt to an average of 21 murders per million people annually from 1985 to 1992, but has dropped steadily ever since.

However there are difficulties in using police stats as described in the article.

Based on conviction statistics using Statistics NZ table builder, from 1985 to 1992 the average annual number of convictions for murder was 27.9, with an average population of 3.375 million, provides a rate of 8.27 per 1 million.

Staying with convictions and the same source, the rate from 2000 - 2007 is 5.93.

Lower but hardly half.

As with car crashes, which I have argued more people are surviving, more people are probably surviving the trauma of assault. So rather than just murder, let's look at overall violence, which by the way, academics are convinced is an affect of unemployment.

Again, sticking with conviction statistics for violence, assuming the worst offending results in a custodial sentence, you can see that there are much lower numbers over the period of high unemployment with a steady rise from 2002.



And just for confirmation, let's look at Police statistics. Importantly these show the recorded rates of violent crime climbing from around 68 per 10,000 of population in 1988 to 140.4 in 2008.



So in summary, for whatever reason, the murder rate appears down. It isn't because there is less violence.

3 comments:

Berend de Boer said...

Just one of those posts where you show your excellence Lindsay. Thanks!

Andrei said...

(If the Ratima and Aromoana murders - aberrant numbers - were removed, the rate would drop to 7.56.)

Since these numbers are based on the statistics of conviction not bodies on the ground Aromoana at least would not be included - as would any other crime for which no conviction were recorded. Or is this a misreading on my part?

The story also states that until the 70s the rate was much lower again less than half that of today. With the caveat of course the way the stats were recorded then may well not match todays.

Still for a conservative like myself this does suggest that the social policies of the sixties generation have a lot to answer for

Lindsay Mitchell said...

Andrei, You are right. In fact the Ratima and Aromoana murders would show in the police statistics - those Collins is using - which contributes to his high rate from 1985-92.