We hypothesize that cultural appreciation of hard work and thrift, the "Protestant ethic" according to Max Weber, had a pre-Reformation origin. The proximate source of these values was, according to the proposed theory, the Catholic Order of Cistercians. In support, we document that the...

Empirically, a higher frequency of lightning strikes is associated with slower growth in labor productivity across the 48 contiguous US states after 1990; before 1990 there is no correlation between growth and lightning. Other climate variables (e.g., temperature, rainfall and tornadoes) do not...