If we adjust for the seriousness of crimes, is crime up or down in West Hollywood?
In past reports, we’ve looked at crime based on the number of reported crimes and the crime rate, which is the number of crimes adjusted for population. One limitation of these measures is that they treat all crimes equally, regardless of how serious they are.
In this analysis, we adjust for that missing factor, the seriousness of crimes. It’s a critical factor. Policymakers and the public react differently to a rise or fall in the number of crimes depending on the types of crimes. Changes in aggravated assaults or robberies matter more than changes in petty thefts or car break-ins.
Definition of the overall “severity” of crime
The Canadian government publishes a “crime severity index” (see Measuring Crime in Canada). For them, “seriousness” refers to the relative importance of different types of crime and “severity” is the overall measure that combines seriousness with the crime rate. We’re adopting their terminology. Expressed as formulas:
Quantifying the seriousness of crimes
The challenge is quantifying seriousness. It requires value judgments about how much worse one crime is than another.
The Canadians use the length of actual prison sentences as the indicator of each crime’s seriousness. We’re following that approach, using the length of prison sentences set by the California legislature for each crime. We had to pick among specific crimes and sentencing levels to represent each type of crime. For example, there are different kinds of homicide. We picked the bottom end of the 15-years-to-life sentence for second-degree murder.
The current mix of these crimes is shown below for West Hollywood. The violent crimes — homicide, rape, aggravated assault, armed robbery, and strong-arm robbery — make up 16%. The rest are property crimes. Petty thefts are a third of the total.
Results: Crime severity versus prior year
We compared the fiscal year that just ended (July 2015-June 2016) to the prior fiscal year (July 2014-June 2015). The overall severity of crime rose 6% in the past year. It was a combination of an 8% increase in the crime rate and a slight decline in seriousness.
Results: Crime severity versus five years ago
We also looked at crime severity over a five-year period. We compared FY2016 to FY2011. Overall crime severity dropped 20%. The decline was driven by a 13% reduction in seriousness and 9% fall in the crime rate versus five years ago. The fall in the crime rate came from a 5% cut in the number of crimes and a 4% increase in the city’s population.
So what’s the answer to our question? One could accurately say that “crime is up in West Hollywood” or that “crime is down in West Hollywood,” depending on the timeframe one chooses for the comparison.
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