There are some exceptions to this decline. Non-residential burglaries spiked in early June, coinciding with the peak of the George Floyd protests, when looting of retail stores was common. Domestic violence has also probably increased. Data are sparse because only a small fraction of victims report being abused, and because police departments can be slow to share what numbers they do have. Research by Emily Leslie and Riley Wilson of Brigham Young University finds that calls related to domestic violence in March to May rose by an average of 7.5% in 14 cities compared with the same period in the previous year.

Alarmingly, murder also seems to be on the rise. So far this year, homicides in big cities appear to be up by around 20% against the average for the same period in 2015-19. Interpreting these numbers is tricky, since murder rates can vary a lot from year to year. An Economist analysis of FBI statistics finds that the total number of homicides in big cities fluctuated from year to year by an average of roughly 20% between 1990 and 2018. Murders in Chicago this year may be up by 51% through July 20th, compared with the same period in 2019, but by only 9% on 2017. Except in a handful of the cities in Mr Abrams’s data set, homicide rates did not change much relative to prior years after government shutdown orders were put in place.