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| Police and prevention go together. Good crime prevention is based on evidence, not popular beliefs |
by Gregory Saville
“No one marches on Washington because of a pie chart!” I heard a politician say that years ago during a campaign. So why does anyone march on Washington, or wherever? Many people march for legitimate reasons. Others don’t. Evidence informs some. Others just believe what they want.
Incredulous as it seems – despite the absurdity of magic pills – some people end up believing populist snake oil when confronted with social unrest, economic strife, or political periods of turbulence. It’s the same in crime prevention. Despite evidence that many prevention methods cut crime, some choose to believe otherwise.
We need an objective system that depends on evidence and rational decision-making.
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| Crime prevention has been a police mandate since 1829. A 1931 family photo of Police Constable Tom Hopkin - my grandfather |
WHAT WORKS?
I remember reading one of the first evaluations of Crime Prevention Through Environmental Design in the 1970s – an elegant, pre-test/post-test research design with tons of data over several years. It examined problems like the maturation effect (how the passage of time taints a strategy) and selection bias (failing to collect random samples). Evaluators examined problems that researchers seldom examine even today, like compensatory equalization, (when a city implements other programs that affect the results). It was state-of-the-art in social science evaluation.
It was a demonstration project called Crime Prevention Through Environmental Design: Final Report on Residential Demonstration, Minneapolis, Minnesota.
That study, and a series of others that followed, were the most exacting scientific studies of CPTED of such size, scope, and quality. They are unrivaled, even today. They revealed the positive results from CPTED of that era. They showed how CPTED was successful when it was holistic and participative with the community. They also showed that CPTED was complex.
What happened? Researchers criticized CPTED as too complex. They claimed it was too difficult to parse out the effect of specific strategies and to control one prevention effect from another. They complained it was too hard to isolate the role of the community from the police and the prevention practitioners.
You cannot please everyone! Nor, in science, should you. The point is not to please people and appease their feelings. The point of science is to learn from mistakes and move closer to truth.
Since then, hundreds of CPTED studies have shown positive prevention results. The most recent claimed: “Reviews of collections of CPTED case studies have in general indicated CPTED interventions typically reduce crime.”
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| Einstein's prediction about the bending of light. Many felt he was nuts - it offended their belief about the world. Scientific experimentation proved them wrong - photo Creative Commons |
BELIEF VERSUS TRUTH
We still lack the scientific rigor to find any “ultimate” truths. That doesn’t mean we cannot find some relative truths. Good scientists say this all the time. Yet, if such flaws exist in the physical sciences, imagine the ailments afflicting social science.
In one review, a City Journal critic of criminological statistics found that “A detailed review of every regression model published between 1968 and 2005 in Criminology, a leading peer-reviewed journal, demonstrated that these models consistently failed to explain 80 to 90 percent of the variation in crime.”
I recently read an evaluation in Sweden that was so flawed, it read like propaganda. It failed to cite any prior evaluation research, provided no methodology, and quantified nothing. CPTED evaluations from 40 years ago put it to shame. Clearly, they have learned zero.
How can we build a library of evidence about effective crime prevention when even social scientists cannot figure out how to do proper science?
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| Clark Stanley's Snake Oil Liniment. One of the earliest cons in the Old West - photo Creative Commons |
SNAKE OIL SALES
If it is a choice between the snake oil propaganda of populist politicians (the “elites” are the problem; let’s go back to the old days), or an objective system that depends on evidence and rational decision-making, I doubt any fair-minded, democracy-loving, intelligent person, would choose the former.
There is no way to know for certain in social science how much more research is necessary. We also do not know whether more evidence, no matter how conclusive, will convince policy-makers to make rational crime policy. Regardless, none of that should dissuade the use of good research and the collection of decent evidence.
As we enter the New Year, I say we should carry on the difficult task of refining crime prevention methods, regardless of sham critics. We must remain vigilant against populist propaganda. We should continue to build, and learn from, libraries of success and failure.
We may not know how to convince the political populists, but without efforts to learn from science, we will forever be in the clutches of one snake oil salesman or another. And, as we know from the history of violence in the 20th Century, that never ends well.
