The demographic history of the Jews in the Middle Ages may be characterized by two main phenomena: i) a sharp drop in the number of Jews until the beginning of the modern period, due mainly to conversions; and, ii) early urbanization. Until now, these features have been analyzed as primarily...

We investigate a setting in which members of a population, bifurcated into a majority and a minority, transact with randomly matched partners. All members are uniformly altruistic, and each transaction can be carried out cooperatively or through a market mechanism, with cooperative transactions...