In recent months, statistics on violent crime have confirmed a troubling trend: Homicide rates in the U.S., long on the wane, shot upward in 2020. Early signs suggest it’s continuing. Many cities have reported new spikes in murder rates in early 2021. Historians — Roger Lane, Eric Monkkonen and others — have long sought to explain why murder rates aren’t static, but rise and fall over time.
Other researchers have built on Roth’s work. They include Peter Turchin, who compiled a database of extra-legal killings by vigilantes as a means of tracking political instability. It tracks quite well with changes in the homicide rate.
Turchin eventually published a book of his own in 2016 that historical data to correlate periods of political instability with violence. He correctly predicted that the U.S. was headed toward a period of discord…..