Wednesday, April 08, 2009

Spewing ink

Yesterday we learned that, contrary to hysteria from the media and the "hang 'em high" brigade, New Zealand's murder rate has in fact halved in the past 20 years. Today ACT MP (and death penalty advocate) David Garrett is desperately spewing ink in an effort to disguise the fact. According to Garrett, the drop is "questionable". He suggests four possible explanations for why:

  • Other types of culpable homicide (e.g. manslaughter) could have risen to more than match the overall drop in murders;
  • "Perverse verdicts" may have led to murders being classified as manslaughters;
  • Advances in medical technology will have led to more people surviving serious assaults; and
  • The post-1994 inclusion of attempted murders and conspiracies may have reduced the statistics.
To address each of these points in turn:
  • Garrett's first assertion is simply false - at least when taken over the last ten years. Crime statistics for the last decade can be viewed with the Department of Statistics Table Builder. Go here, click on National Annual Recorded Offences for the Latest 10 Calendar Years, then click on "violence" and then "homicide" to get a breakdown. In the past decade, absolute numbers of manslaughters have remained fairly flat (though there is a lot of random variation). Numbers of other culpable homicides Garret appeals to - infanticides, for example - are so low as to be negligible (if you want to do a population analysis, population stats for December years are here).
  • The police use offence statistics, not conviction statistics. It is a question of what it is reported as and initially recorded as by police (the explanation is here). What someone is eventually convicted of is completely irrelevant to the data.
  • A serious assault which previously would have killed someone but now merely puts them in hospital is still likely to be prosecuted as (attempted) murder or manslaughter, depending on the level of intent involved.
  • The broadening of the definition of "murder" to include attempts and conspiracies will have increased the rate, rather than reduced it.

In short, Garrett's "explanations" just don't stack up. But then, they were never meant to. Rather than engaging seriously with the facts and the empirical evidence, Garrett is merely attempting to sow confusion and present the appearance that they might be questionable, so he can continue to push his sadistic, vengeance-based "tough on crime" agenda.