Witching hour

I read a paper by a Harvard graduate student on the relationship between witch trials, temperature, and economic growth. She found a robust relationship between temperature readings in Europe and the number of witch trials. It appears that as the average temperature becomes extremely low, witch trials spikes. She relates this to agricultural outcomes, when the weather is abnormally cold, crops fail and sources of food become more scarce, thus more incentive to blame certain segments of society.

An interesting tidbit in this study was that in Tanzania, a researcher has observed that supposed witches (often the oldest female household member) were executed not by the village, but by family members. These executions are also correlated with downturns in food production, which makes one think that it might be an attempt to eliminate the least productive member of the family with the accusation of witchcraft as cover.