There is a connection between economic stress and the violence directed at minority groups, says Mark Koyam, Assistant Professor in Economics at the US-based George Mason University.
His research shows “that economic insecurity and weak political institutions give rise to persecution and violence against minority groups”, he explains in a video.
To prove this, Koyam and two colleagues looked at 1,000 years’ of data on pogroms around Europe.
It showed that when harvests were likely to be poor, minority groups had a 50% increased chance of being targeted.
“There’s always an incentive or desire to blame outsiders for various disasters but we think that it’s in times of crisis that this comes to the fore,” Koyam said.
There is no GDP data for most of those 1,000 years, so the researchers looked at climate data to tell what the weather was, and hence agricultural conditions, in a particular time.
For instance a number of years of cold weather could cause famine and difficult living conditions.
“It’s in those type of conditions that we would see people looking for someone to blame and to scapegoat,” he said.
Following the Middle Ages, Koyam notes, as economic conditions changed with more integrated markets and more trade, the link between climate and pogroms disappears.