Another Guest Post from David Garrett:
Correlation causation andÂ crime â the effect of active policing and sentence enhancement
When I was in parliament I sometimesÂ had Â coffee with Rick Barker, a fellow member of the Law and Order Select Committee and a damn good bloke. Rick told a Â great story illustrating how correlation and causation can be confused â even by those who should know better.
During WW II, no bananas were imported into Britain, they presumably being deemed not to be an essential food, or just not readily available. After the war, banana imports resumed â and it was noted that within nine months or a year, Â the birth rate had sharply increased. For a time, banana sales went through the roof, as its âaphrodisiacâ qualities became widely known. It was apparently some years â and after a couple of studies found no basis for bananas enhancing fertility â before it was realized that banana imports and rising birth rates were just a coincidence. The birth rate had risen Â not because of bananas, but because at the same time Â more and more young men were âde-mobbedâ and came home to their wives and girlfriends.
When crime plummeted in New York State following the introduction of âbroken windowsâ policing, those on right said smugly that the reduction in crime followed logically from more intensive policing. Those on the left said falling crime rates were just like those banana imports â changes in policing policy had nothing to do with it.
While Â itÂ is now pretty much over in the US, for ten or fifteen years the debate raged, with lefties âfeverishly searching for the ârealâ reason crime rates plummetedâ, to quote the late Dennis Dutton. Any Â reason would do -Â because surely it couldnât be simple old style policing. Could it?
All sorts of âreasonsâ were suggested to explain away the precipitate drop in crime, from âdemographic bubblesâ passing through the population, to the crack epidemic which had been plaguing New York and other states waning . And of course Â the now famous âmore readily available abortionsâ theory suggested by economist Steven Levitt. This theory of cause and effect is in Levittâs âFreakonomicsâ and Â his paper âUnderstanding why crime fell in the 1990âs: four factors that explain the decline and six that do not.â Â in âJournal of Economic Perspectivesâ Vo. 18, 1: pp. 163-190
Leftist commentators always focus on the âmore readily available abortionsâÂ factor Levitt identifies without ever mentioning two things: that the abortion Â âfactorâÂ is number four on his list of four; and the two factorsÂ toÂ which LevittÂ ascribes most of the reduction are more police per capita, and much greater use of punitive sentencing policies.Â While almost every one knows New York is the home of âzero tolerance policingâ a.k.a. âbroken windowsâ, it is less well known that New York state also Â has âsentence enhancementâ laws, of which three strikes is one variant.
While lefties often derisively refer to the US experience, I suggest we can learn a lot from that country â both what works and what doesnât.Â Those who have traveled widely in the US quickly realize that to a considerable extent it is a land of fifty different Â nations. The Boston Brahmins have about as much in common with the good old boys of Louisiana and Tennessee as New Zealandâs effete artistic elite have with banana growers in Far North Queensland.
So what does the US experience tell us about how best to reduce crime?Â The most obvious lesson is that a combination Â of more police on the streets and Â sentence enhancement of one sort or another makes the biggest impact.Â This is the major lesson from the New York experience; Â it is that state which has seen -by a considerable margin – Â the greatest reduction in crime of all types since the 1990âs.
Secondly, Â sentence enhancement works. Levitt himself, the darling of the left â at least on thisÂ issue – Â says so himself. Twenty six states have introducedÂ âthree strikesâ laws which vary widely in their ambit and effect. Some statesÂ – such as California – use their Â laws far more than others do. With a couple of exceptions, there appears to be a close correlation between the usage of three strikes laws and the level of crime reduction: those states that apply their laws more have seen much greater reductions in crime of all types than those states which do not.
For the left, this is of course an âinconvenient truthâ to borrow from Al Gore, but it is a truth nevertheless. It has often been said â includingÂ by commenters here on Whaleoil â that the drop in crime across the US, and in other countries in the western world is âunexplainedâ.Â What they really mean is if you discount the obvious, then no-one can agree on any other explanation.
Those with both common sense and a degree or two find the lessons from the US clear: put more police on the streets and lock serious felons up for longer, and crime will drop. In the last two years we Â have introduced a three strikes law, and put more police on the streets of South Auckland which has the highest levels of crime in the country. And as a result, Â those crime rates are falling, along with prisoner numbers. God help us if the socialists get their hands on the levers of power in 2014.