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POLICY BRIEF: “FERGUSON EFFECT”?

Was There a “Ferguson Effect” on
Crime in St. Louis?
Richard Rosenfeld, University of Missouri - St. Louis

Some commentators have asserted that crime has increased as the result
of recent protests against police misconduct. However, there is no credible
and comprehensive evidence about any such effect.
Does widespread and heavily publicized protest activity
directed at alleged police misconduct result in higher
crime rates? That is the view of some commentators,
who attribute recent crime increases to what has
been termed the “Ferguson effect.” The idea is that
heightened criticism of the police has demoralized,
angered, frustrated, or otherwise caused police officers
to refrain from vigorous enforcement activity, resulting
in more crime (e.g., Mac Donald 2015).

few miles from Ferguson, in the months before and after
Michael Brown was killed. A superficial glance at St.
Louis crime statistics might lend some credence to the
view that crime increased in response to the events in
Ferguson. After declining or holding steady for several
years, the number of violent crimes in St. Louis rose by
5.3% in 2014 over the previous year. The increase in
homicide was especially pronounced. In 2014, the police
department recorded 159 homicides, a 32.5% increase
over the 2013 total of 120. Local officials as well as
Is there evidence that crime rates are, in fact, increasing national commentators attributed the crime increase in
around the country? It depends on where you look. In St. Louis to the police shooting in Ferguson that led to
some cities, some types of crime are up over last year and protest demonstrations in St. Louis as well as Ferguson.
other types are not, while other cities have not recorded
increases in any major crime category. Unfortunately, To determine with certainty whether the Ferguson
we cannot rely on the nation’s leading crime data systems events caused crime increases in St. Louis (or elsewhere),
for a comprehensive view of recent crime changes. The we would have to know what would have happened to
Bureau of Justice Statistics’ National Crime Victimization crime had the Ferguson events not happened. Proving
Survey does not produce city-level crime data. The the counterfactual – whether y would not have occurred
FBI’s Uniform Crime Reports does provide crime data for had x not occurred – is challenging, to say the least. In
individual cities, but the data are not timely enough for this case, however, we can begin by asking whether the
monitoring crime changes over the past several months. timing of the Ferguson effect hypothesis corresponds
So, everybody’s data is anecdotal, a cherry picker’s with observed crime changes in St. Louis. Obviously,
delight. If you want to tell a story of crime increases,
you can. If not, just pick from a different tree.

ANALYZING A POSSIBLE “FERGUSON EFFECT”
So, how might we evaluate the so-called Ferguson effect
on crime? One way is to go to the source, or close to
it, and examine crime changes in St. Louis, located just a

Obviously, the Ferguson events or
subsequent police shootings could
not have produced crime increases in
St. Louis if those increases took place
before Michael Brown was killed.

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POLICY BRIEF: “FERGUSON EFFECT”?

the Ferguson events or subsequent police shootings
could not have produced crime increases in St. Louis
if those increases took place before Michael Brown was
killed. If the increases occurred afterward, that would
not prove they were caused by the controversial police
shootings, but it is a necessary condition for drawing
causal inferences.

If the crime increases occurred after
the Ferguson events, this would not
prove that they were caused by the
controversial police shootings, but it
is a necessary condition for drawing
causal inferences.

Figure 2. Ratio of St. Louis Homicides by
Month, 2014/2013
4.0

4.0

3.5

3.5

Michael Brown killed

3.0

3.0

2.5

2.5

2.0

2.0

1.5

1.5

1.0

1.0

0.5

0.5

0

0.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

same period in 2013. The ratio then decreased but began
to rise again in June, two months before Michael Brown
was killed, and at no time in the following months did it
HOMICIDE RATES
exceed the levels reached earlier in the year. These results
Figure 1 displays month-by-month homicide frequencies do not support the belief that the St. Louis homicide
in St. Louis in 2013 and 2014. The homicide count increase in 2014 was attributable to the Ferguson events.
was higher in 2014 than in 2013 throughout most of
the year, but it is not readily apparent from the figure OTHER VIOLENT CRIME RATES
whether the gap grew after Michael Brown was killed in
early August of 2014. To establish whether the police The picture differs somewhat for other violent crimes.
shooting in Ferguson and resulting protests may have Figure 3 displays the monthly ratio of violent crimes in
triggered an increase in homicide, the month-by-month 2014 to violent crimes in 2013. We see that the ratio grew
ratio of homicides in 2014 to homicides in 2013 is shown early in the year, decreased for two months, and then
in Figure 2. Here we see that homicides were far more increased again through the end of the year. But that
frequent in the early months of 2014 compared with the increase began in May, well before the police shooting in

Figure 1. St. Louis Homicides by Month, 20132014

Figure 3. Ratio of St. Louis Violent Crimes by
Month, 2014/2013
1.5

25

Michael Brown killed

Michael Brown killed

20

15

1.0

2014

10

2013

0.5

5

0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

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POLICY BRIEF: “FERGUSON EFFECT”?

Ferguson. The rate of increase in the violent crime ratio,
however, does appear to have accelerated beginning in
September. The timing of these changes offers mixed
support, at best, for the Ferguson effect hypothesis.

PROPERTY CRIME RATES
Figure 4 displays the ratio of property crimes in 2014
over 2013. The monthly change in the property crime
ratio offers the strongest evidence in support of the
hypothesis that the Ferguson events led to crime
increases in St. Louis, at least with respect to timing.
The property crime ratio was fairly flat until August,
when it began to increase steadily through the remainder
of the year. Before August, St. Louis averaged about
15% fewer property crimes in 2014 than in 2013. From
August through the end of the year, the city averaged
8% more property crimes than during the same period
the year before. By December, the number of property
crimes in 2014 exceeded the number in 2013 by 27%. If
there was a Ferguson effect on crime in St. Louis, it was
most pronounced in the growth of property crimes.

Figure 4. Ratio of St. Louis Property Crimes by
Month, 2014/2013
1.5
Michael Brown killed

1.0

We can conclude with reasonable
certainty that the events in Ferguson
were not responsible for the steep
rise in homicide in St. Louis.
CONCLUSION
Whatever their cause, double-digit homicide increases in
St. Louis and other cities during the past several months
should not be discounted as unimportant or as mere
“random fluctuations” in crime statistics – not when so
many lives are at stake. But neither should the recent
increases be read as a new crime wave, at least not yet.
Even with a 33% increase over the previous year, the St.
Louis homicide rate in 2014 remained well below the
peak levels reached in the early 1990s (see Figure 5). We

Figure 5. St. Louis Homicide Rate per 100,000
Population, 1985 - 2014

0.5

0

increase in violent crimes over 2013 accelerated after
August. Only the timing of the change in property
crimes is fully consistent with a Ferguson effect. But
temporal consistency is not a sufficient condition to
establish substantive proof. Many factors may have
contributed to a rise in property crimes, and perhaps also
violent crimes, in St. Louis after August of 2014, and
we cannot conduct an experiment to discover whether
crime would have increased had Michael Brown not
been killed in a controversial police shooting. But we
can conclude with reasonable certainty that the events
in Ferguson were not responsible for the steep rise in
homicide in St. Louis.

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

CRIME DATA SUMMARY
Even limiting an analysis just to the timing of these
monthly crime changes provides only partial support
for the contention that the police shooting in Ferguson
and ensuing protest activity spurred crime increases in
St. Louis. The increase in homicide in 2014 predated
Michael Brown’s killing on August 9. Violent crimes
exhibit much the same pattern, although the rate of

70
60
50
40
30
20
10
0

1985

1990

1995

2000

2005

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POLICY BRIEF: “FERGUSON EFFECT”?

should watch the new increases carefully and encourage
local police departments to apply evidence-based best
practices in response. In the absence of credible and
comprehensive evidence, sounding alarm bells over a
“Ferguson effect” or any other putative cause will not
help.

REFERENCES
Bureau of Justice Statistics. 2015. Reported crime by
locality (city, county), state, and Nation. http://www.bjs.
gov/ucrdata/Search/Crime/Crime.cfm. Accessed June
11, 2015.
Mac Donald, Heather. 2015. The new nationwide
crime wave. Wall Street Journal (May 29). http://
www.wsj.com/articles/the-new-nationwide-crimewave-1432938425. Accessed June 11, 2015.
St. Louis Metropolitan Police Department. 2015. Crime
Statistics: Crime Summary by Neighborhood. http://
www.slmpd.org/crime_stats.shtml. Accessed June 11,
2015.

This briefing paper was written by Richard Rosenfeld, Ph.D.,
Founders’ Professor of Criminology and Criminal Justice at the
University of Missouri - St. Louis. He chairs the Crime Trends
Roundtable sponsored by the National Research Council of the
National Academy of Sciences.
1705 DeSales Street NW, 8th Floor
Washington, D.C. 20036
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