Speaking of Crime Statistics
If you tuned in to the presidential debate on Tuesday, you may have heard crime statistics mentioned. Vice President Biden stated: “And the fact of the matter is violent crime went down 17%, 15% in our administration.”
What was the source of these statistics, and was the Vice President correct?
John Bailer, Rosemary Pennington, Richard Campbell, and I discussed where crime statistics come from on the latest episode of the Stats + Stories podcast, published October 1. We did not discuss the presidential debate (the podcast was taped in July), but we talked about how crime statistics are represented, and sometimes misrepresented, in news reports.
As we discussed during the podcast, and you can read about in my book Measuring Crime: Behind the Statistics, the United States has two major sources of crime statistics. Vice President Biden cited statistics from the Uniform Crime Reports (UCR), which are compiled by the FBI from data supplied by law enforcement agencies around the country. The UCR reported 458.6 violent crimes per 100,000 population in 2008, the year before Obama and Biden took office, and 386.3 violent crimes per 100,000 population in 2016, their last year in office, so yes, this represented a 15.8% drop in violent crime rates during the eight-year period of their time in office.
But the Uniform Crime Reports include only those crimes that are reported to, and recorded by, the police. If the actual number of crimes that occurred is the same for two successive years, but fewer of them are reported to the police in year 2, the UCR crime statistics will be lower in year 2 than in year 1. That’s why, when discussing crime rates, one also wants to look at the other major source of crime statistics.
The National Crime Victimization Survey asks a representative sample of persons across the nation about their experiences with crime: did any crimes happen to them and, if so, what were the details of the crime(s)? It also asks whether each crime was reported to the police. The survey thus measures crimes that are unreported to police as well as those that are measured by the UCR, and gives estimates for the percentage of crimes of each type that are reported to the police. You can read more about how this survey defines and measures different types of crimes, in my book Measuring Crime: Behind the Statistics.
According to the National Crime Victimization Survey, there were 25.3 violent crimes per 1,000 persons age 12 and over in 2008, and 19.7 violent crimes per 1,000 persons age 12 and over in 2016. This represents a 22% decrease in violent crimes over the time period.*
The Vice President thus accurately described the decrease in violent crime during the Obama-Biden administration, according to the statistics from the Uniform Crime Reports. He actually understated the decrease in violent crime over the period according to the statistics from the National Crime Victimization Survey. The NCVS statistics are often considered to give more accurate measures because they are not affected by the variability in crime recording practices across law enforcement agencies and they also include crimes that were not reported to the police.
What about crime statistics during the COVID pandemic? Individual police departments have published preliminary statistics, but we won’t really know the full picture until 2021, when the 2020 estimates are released. It’s also possible that the pandemic will have affected not just the crime rates, but the crime measurement process.** Stay tuned.
Copyright (c) 2020 Sharon L. Lohr
Footnotes
*The lowest violent crime rate during the period 2008-2016, according to the National Crime Victimization Survey, was in 2015, when the survey reported 18.6 violent crime victimizations per 1,000 persons age 12 and older. See my previous post on the 2018 NCVS statistics for a graph of violent crime rates between 1993 and 2018.
**The pandemic may have affected patterns of reporting crimes to the police. It also may have affected the National Crime Victimization Survey statistics for 2020. The survey collects much of the data by telephone, but relies on in-person visits to households that do not respond by telephone. Between March and July 2020, in-person interviews were suspended. Persons interviewed in person for the NCVS report approximately twice as many violent crime victimizations as persons interviewed by telephone, so the switch to all-telephone interviewing may affect NCVS estimates of violent crime during 2020.