In 2004 Emily Oster of Brown University found a correlation between the frequency of witch trials and poor weather during the “Little Ice Age”. Old women were made scapegoats for the poor harvests that colder winters caused. A more recent paper by Noel Johnson and Mark Koyama of George Mason University argued that weak central governments, unable to enforce the rule of law, allowed witch-hunts to take place. They found the ability to raise more in taxes, a proxy for growing state power, to be correlated to a decline in witch trials in French regions.
A paper published in the August edition of the Economic Journal casts doubt on both theories. Peter Leeson and Jacob Russ, also of George Mason University, collected data for witch trials from 21 countries between 1300 and 1850, in which 43,240 people were prosecuted. They found that the weather had a statistically insignificant impact on the occurrence of witch trials. The impact of negative income shocks or governmental capacity was also very weak.
When Mr Leeson and Mr Russ compared their witch-trial data to the timing and location of over 400 battles between Christian denominations, they found a much closer link. Where there was more conflict between Catholics and Protestants (in Britain, between Anglicans and Presbyterians), witch trials were widespread; in places where one creed dominated there were fewer. The authors conclude that churches engaged in a sort of “non-price competition”, gaining converts in confessional battlegrounds by advertising their commitment to fighting evil by trying witches.
Here is the full story from The Economist.