How to Compare Crime in Different Places

The first in a series on crime statistics

Comparing the amount of crime in two places is trickier than most people realize.

Photo by Tingey Injury Law Firm on Unsplash

Criminals have a vested interest in not being found out. Victims don’t universally report crimes committed against them, for reasons ranging from not thinking minor crimes are serious enough to report to not believing the police will help them. Governmental agencies have their own agendas and can make information easier or harder to find in ways that align with those agendas.

So, how do we figure it out?

The place to start is with official statistics, as flawed as they may be.

Official statistics will give you a picture of crimes known to police

That’s for a specific area, in a given period.

When someone does report a crime to the police or police otherwise become aware of a crime, part of their job is to record information about that crime. Ideally, that happens for every crime the police investigate. Then, all the different crimes known to a police organization will get counted up, making it possible to know how many crimes of each type have been documented.

There are well-known limits to official statistics. An example of those limits is that because these statistics are based on crimes known to police, they depend on people reporting crimes to police and police recording the crimes consistently. Unfortunately, neither of those is guaranteed.

Some crimes are just less likely to be reported than others. For example, sexual assault is a serious crime that nonetheless is underreported.

Police departments don’t always record the same types of incidents as the same crimes.

These facts mean that official statistics don’t exactly reflect the actual number of crimes committed.

There are other kinds of crime statistics.

Victimization and self-report surveys involve asking representative samples of the population about their experiences with crime, as victims and as criminals respectively. By extrapolating from the results, researchers can estimate the levels of…