Since I’ve been creating these graphs based on CDC data on deaths, I’ve been asked about seasonality patters. Yes, black homicide deaths are more seasonal than white homicide deaths. From 1999 to 2019, black homicide deaths in July averaged 19.3% higher than in January, while white homicides average 5.7% higher in July than January. Black seasonality was stronger than white seasonality in 19 of the 21 years. (These are numbers for victims of homicide, not for perpetrators. Both figures are for non-Hispanics.)
The fairly strong seasonality for black homicides suggests more evidence for my suggestion that, in contrast to Case and Deaton’s “Deaths of Despair” among whites from opioids, suicides, and liver damage, black on black homicides tend to be more “Deaths of Exuberance.”
One possibility is that summer outdoor parties in the inner city tend to be larger in space and attendees than winter indoor parties, and the more inner city blacks attending a party, the higher the chance per capita of Unwanted Party Guests and a subsequent shooting. At a January house party, you can more easily turn troublesome people away at the door, but a July picnic in the park has a large, hard-to-guard perimeter. But that’s just speculation.
I’ll go on later to look at other ethnicities and traffic fatalities. White traffic fatalities looks to be quite seasonal but I haven’t checked the numbers yet.
(Methodological notes: both January and July have 31 days. February usually leads the year in fewest homicides partly for seasonal reasons, partly because it only has 28 or 29 days. To avoid effects of long term trends, I divided each year’s July figure by the average of the figures for the preceding and subsequent Januaries. I couldn’t include 2020, with its historic trend effect after George Floyd’s death, because January 2021 was only 16 months ago and you can hardly expect the federal government to keep you up to date on homicide stats. What do you think this is, baseball? Homicides are a matter of life and death, so you’ll just have to wait to find out if the latest policies are saving lives or killing people.)
