NOPD’s response times are clearly increasing in 2015, as I (and others) have previously written. That conclusion begs the question: “What impact does longer response times have on crime statistics?”
Unfortunately, the resulting analysis finds that longer responses are deflating crime statistics by increasing the likelihood that a crime will be found unfounded. Using publicly available data we can estimate that about 6 percent more crimes are being marked unfounded in 2015 than would have been had response rates stayed at 2014 levels. This translates to over 1,000 more crimes being marked unfounded than expected over the course of a year, all because of slower responses.
Impact on Investigations
The result of longer response times, at least anecdotally, appears to be a higher likelihood that a crime will be marked unfounded, and thus not fully investigated. Consider the case of the comedy club break-ins over the summer, in which the slow response directly led to the crime being marked unfounded.
Because of longer response times, a higher percentage of Property crimes and, to a lesser extent, Person crimes are being classified as unfounded in 2015 as compared to 2014. This conclusion is reached by comparing the ratio of Property and Person crimes marked RTF from 2011 to 2014 with the ratio in 2015. The results displayed below, especially for Property crimes, are discouraging.
Using this information, we can estimate how many crimes would have been reported to the FBI in 2015 had 2014 rates remained constant. Think of it as inflation for crime statistics. Crimes were marked RTF at slightly below the 2011 – 2014 average for 2014 Person crimes and they were marked at slightly below the 2011 – 2014 average for Property crimes, so 2014 is a pretty good barometer for crime “deflation” in 2015.
Using 2014 response times, we would expect New Orleans to be on pace for nearly 1,050 more major crimes in 2015 than the actual pace of crimes marked RTF. The vast majority of this difference is in Property crimes, as Person crimes are fairly close to (albeit slightly below) the expected total. Click on the image below to zoom in.
Another way to look at this difference is by comparing the expected change in crime totals at 2014 response rates to the actual reported change in crime totals. As of late September, New Orleans is on pace for a roughly 7.8 percent drop in Person and Property crimes relative to 2014. The expected crime total at 2014 response rates, however, suggests we should be on pace for a roughly 2.2 percent drop this year, a difference of nearly 6 percent. Perhaps more troubling, both the actual and expected crime totals have been rising steadily since April.
It is worth noting that the gap between expected and actual crimes is shrinking slightly as of late October. Regardless, this analysis shows fairly clearly that a large number of crimes that would have been marked RTF will go unreported in official crime statistics in 2015.
This is a critical issue for the City of New Orleans. The city having made progress in reducing gun violence, but these types of crimes impact a wide swatch of the city. Finding solutions to the response time crisis is critical, and this analysis provides a potentially important methodology for gauging the success or failure of those solutions.
MORE RESPONSE TIME COVERAGE
This post was originally published by The New Orleans Advocate.