Total factor productivity (TFP) differs greatly across countries. In this paper, I provide a novel rationalization for these differences. I consider two environments, one in which enforcement is full and the other in which enforcement is limited. In both settings, manufactured goods can be produced using a high-TFP technology or a low-TFP technology; there is a fixed cost associated with adoption of the former. I suppose that the fixed cost is sufficiently small that adoption takes place in a symmetric Pareto optimum in the limited-enforcement setting. Under this condition, I prove two results. First, adoption takes place in all Pareto optima in the full-enforcement setting. Second, adoption may not take place in a Pareto optimum in the limited-enforcement setting, if the division of social surplus is sufficiently unequal. I conclude that limited enforcement and high inequality interact to create particularly strong barriers to riches (in the language of Parente and Prescott (1999, 2000).