US murder rate on track for a big drop
The murder rate in the United States in 2018 is on track for the largest one-year drop in five years.
The numbers are not final, and the FBI will not formally report 2018’s murder figures until September 2019.
But based on a compari- son of 2017 data and 2018 data for 66 large American cities ( population over 250,000), we can observe the trend as it is occurring and offer a reasonable forecast.
Murder rose 23 percent nationally between 2014 and 2016 before leveling off in 2017. Major increases in murder in Chicago and Baltimore received much of the national attention, but the increase occurred throughout the country.
In the cities in which data is available, murder has been down about 7 percent on average this year relative to the same point in 2017.
Estimating national trends from a sample of cities can be tricky because big cities tend to overstate national trends. If murder is up substantially in big cities, you can typically expect that the national murder rate is also up, but a little less so. And if murder is substantially down in big cities, you can usually expect a smaller drop nationally.
The Brennan Center in 2017, for example, found a 4.4 percent decline in 29 large cities for which data was available. Yet the FBI’s national murder count was essentially unchanged in 2017 relative to 2016. (It was officially down 0.7 percent, but that was because the FBI revised 2016’s murder total upward, to 17,284 from 17,250.)
The sample of cities we are using in this article accurately predicted the movement of the national murder change every year but 2002, when murder was down 1.4 percent in the big cities but up 1.1 percent nationally. On average, the sample of cities overstated the national trend by 2.4 percentage points.
If these big cities end the year down about 7 percent from 2017, and if big cities tend to overstate the national trend by about 2.4 percentage points on average, murder should be down by around 4 percent to 5 percent nationally this year.