Arrests, Proportions and Critical Thinking

In the aftermath of the incident in Ferguson, MO, there have been several reactions.  One was a recommendation that more police forces adopt the use of personal video devices with the expectation that a reviewable video of a scene will be more reliable than the possible conflicting testimonies of those involved or of other witnesses, especially when one or more persons involve may have been killed and cannot speak for themselves.  A second reaction is a call to reduce the biased actions of police officers as they carry out their duties along with the assumption that more diversity in the police force will be a step in solving the problem.

The second is highlighted in this article from the Indianapolis Star.  Following the lead of the USA Today, the columnist discusses in detail the disproportionate number of blacks that are arrested when compared to the distribution of the population.  The USA Today reviewed statistics of arrest records for numerous cities across the country.  The Star columnist wants to bring this message home to his readers by pointing out that the state is not “squeaky clean” when it comes to these statistics.  Like many cities in other states, several Indiana cities have a worse record than average and even worse than Ferguson, MO itself.  For example, Johnson County shows the highest racial disparity as “black people are nearly nine times as likely to be arrested as people of other races” and in Carmel, an affluent suburb of Indianapolis, “blacks are more than six times as likely to be arrested as others.”

The writer acknowledges that the explanation of the disparities “— educational and economic gaps that influence crime, or biased policing — isn't clear.”  Various police representatives point out that comparisons have been made between arrests and the makeup of the local population while not all arrests involve citizens of the city or county in question.  Arrests of visitors drawn to the area by a large shopping mall or other attraction may skew the results.

That is all well and good, but why pay so much attention to these kinds of numbers in the first place?  Admittedly, the explanation of the disparities is not clear, and other factors may well be involved, but it’s tempting to cite these statistics because they do tend to reinforce perceived issues.  But how much faith can we really put in them without some additional evidence?  Take another example:  there are slightly more women than men in the state of Indiana, yet in 2013 more than 5 times as many men as women were admitted to prison.  Is this by itself, by any stretch of the imagination, evidence of bias or profiling?  Likewise the US Department of Education shows a racial disparity among high school graduation rates, yet we see no outcry against teachers.

The point here is that we mustn’t be too quick to jump to conclusions.  Sometimes these disparities are truly symptoms of underlying problems, but sometimes it’s just the way things happen without any sinister implications.