Before the eighth–ninth centuries CE, most Jews, like the rest of the population, were farmers. With the establishment of the Muslim Empire, almost all Jews entered urban occupations despite no restrictions prohibiting them from remaining in agriculture. This occupational selection remained their distinctive mark thereafter. Our thesis is that this transition away from agriculture into crafts and trade was the outcome of their widespread literacy prompted by a religious and educational reform in Judaism in the first and second centuries CE, which gave them a comparative advantage in urban, skilled occupations. We present evidence that supports our argument.