Emily Oster, an economist at the University of Chicago, has tried to gather systematic data on the link between witch trials and the weather. The results look striking: Between 1520 and 1770, colder decades go hand-in-hand with more trials. The link may be simply that witches were often blamed for bad weather. Or there may be a less direct link: People tend to lash out in tough times. There is some evidence, for instance, that lynching was more common in the American South when land prices and cotton prices were depressed. Such deaths are, sadly, not a historical footnote. In Meatu, Tanzania, half of all reported murders are "witch killings." Such murders have been documented elsewhere in Africa, Bolivia, and rural India. The difference between the historical executions and modern attacks are that a Tanzanian "witch" typically dies at the hands of her own family. The machete is the weapon of choice. Edward Miguel, an economist at the University of California, Berkeley, and co-author of Economic Gangsters, a book about the economics of crime, corruption, and war, has studied the Tanzanian situation. He argues that there is a direct economic motive for the attacks. Tough times in a Tanzanian household may well result in starvation, and the elderly—especially women—are at risk of being sacrificed to free resources. As evidence, Miguel points out that victims of witch attacks in Meatu district—almost all old women—tend to be from the poorest households. The murders are much more common during years of drought or flood. http://www.slate.com/id/2200227/
