A look at the Crime Severity Index - Video transcript
Quick history lesson on crime!
(Onscreen text: "Quick history lesson on police-reported crime data")
Since the 1960s, official police-reported crime has been understood through the lens of the conventional crime rate, which measures the amount of crime reported by police in an area.
(Onscreen text: "1960")
(Onscreen text: "Crime rate")
The rate is a count of crimes divided by the area's population.
(Onscreen text: "Count of crimes divided by an area's population ")
Each crime affects the rate the same as any other crime.
(Onscreen text: "Each crime affects the rate the same as any other crime.")
For example, one murder has the same impact on the crime rate as one property theft.
Therefore, the conventional crime rate is typically influenced by changes in high-volume and relatively less serious crimes.It is less effective at reflecting changes in less frequent crimes, even if they are more serious.
Keep watching as we fast-forward to 2009.
(Onscreen text: "1960-2009")
The Crime Severity Index, or CSI, was developed in 2009 as a new analytical measure to complement the crime rate and address its limitations.
(Onscreen text: "Crime Severity Index")
The CSI is an area-based measure that considers both the volume and the relative severity of crimes, then tracks changes over time.
(Onscreen text: "Severity, Volume and Over time")
It measures police-reported crime in an area—a city, a province or territory, or the country.
But how does it work?
(Onscreen text: "But how does it work?")
An area's CSI is determined by attributing a weight to each type of crime reported by police and then multiplying the number of crimes by their assigned weights.
(Onscreen text: "Robbery, % of those who are sent to prison, Average number of days sentenced, Weight, 72.9% x 640 = 466")
The weight applied to a given crime reflects its severity and is based on court sentences over the past five years.
(Onscreen text: "Weight x Number of robberies")
Then, the total weighted distribution is divided by the area's population, similar to how the crime rate is calculated.
(Onscreen text: "Total weighted distribution divided by the Area's population")
So, what's the key difference?
(Onscreen text: "So, what's the key difference?")
It's simple: the CSI is a weighted volume measure of crime, while the crime rate is only a volume measure.
(Onscreen text: "CSI = Weighted volume")
(Onscreen text: "Crime rate = Volume measure")
So, if a very serious crime, like murder or robbery, experiences a change in volume, the impact on the CSI will be more significant than the impact on the crime rate.
(Onscreen text: "Crime rate")
By contrast, changes in less serious crimes, such as mischief, minor theft or disturbing the peace, will have less impact on the CSI than on the crime rate.
(Onscreen text: "Crime Severity Index")
(Onscreen text: "Murder has 280 times the impact of property theft.")
It's important to note that the CSI is not the full story of crime and safety in an area—instead, it's one element among many.
(Onscreen text: "CSI, Crime rate, Perceptions of safety, Courts, Corrections and Self-reported victimization.")
Let's say we are looking at crime data for AnyTown.
(Onscreen text: "Anytown")
The crime rate is higher than the national average and has stayed about the same over the last 10 years, but the CSI value has dropped significantly.
(Onscreen text: "higher than the national average and has stayed about the same over the last 10 years")
(Onscreen text: "CSI")
When we look closer, more serious offences, such as robberies, assaults, and break and enters, have decreased each year.Meanwhile, cases of shoplifting have been going up.
Looking at a few other things, we see important changes in AnyTown's demographics, labour market, access to services, and perceptions of safety and sense of belonging.
(Onscreen text: "Demographics, Labour market, Access to services and perceptions of safety.")
Also, local police have developed awareness campaigns to combat shoplifting, which have been covered by the local media and encouraged more reporting.
(Onscreen text: "Smile, your on camera!")
We see too that self-reported perceptions of safety in AnyTown have increased over time. This means people generally feel safer now than they did 10 years ago, despite the crime rate remaining about the same over time.
The CSI, like any indicator, should be interpreted within the broader context of the area being studied.
(Onscreen text: "CSI, Crime rate, Perceptions of safety, Courts, Corrections and Self-reported victimization.")
It is important to analyze factors holistically rather than in isolation.
(Onscreen text: "Crime data, Education data, Health data, Economy and labour force and Population")
Combining information allows us to compare changes in crime over time, as well as across geographic areas, when controlling for the unique circumstances of each area.
Each year, Statistics Canada publishes detailed reports and data tables with analysis and footnotes to help explain the changing landscape of crime trends. These are developed with standardized and comprehensive data reported by police services across Canada.
The CSI is one indicator that helps Canadians better understand the country—its population, resources, economy, environment, society and culture.
(Onscreen text: "Crime Severity Index")
To learn more about the CSI, please visit www.statcan.gc.ca and see the additional links in the description.
(Onscreen text: "www.statcan.gc.ca")
Additional information
For additional contextual information within and outside the criminal justice system, see the following resources: