We model a consumer's efforts to reduce the discount on future utilities. Our analysis shows how wealth, mortality, addictions, uncertainty, and other variables affect the degree of time preference. In addition to working out many implications of the model, we discuss evidence on consumption, savings, equilibrium, and the dynamics of inequality. We claim that most ofthat evidence is consistent with the predictions of our approach.

Our analysis treats advertisements and the goods advertised as complements in stable metautility functions, and generates new results for advertising by building on and extending the general analysis of complements. By assimilating the theory of advertising into the theory of complements, we avoid the special approaches to advertising found in many studies that place obstacles in the way of understanding the effects of advertising. We also use this approach to evaluate advertising from a welfare perspective. Whether there is excessive or too little advertising depends on several variables: the effects on consumer utility, the degree of competition in the market for advertised goods, the induced changes in prices and outputs of advertised goods, and whether advertising is sold to consumers.

This paper considers specialization and the division of labor. A more extensive division of labor raises productivity because returns to the time spent on tasks are usually greater to workers who concentrate on a narrower range of skills. The traditional discussion of the division of labor emphasizes the limitations to specialization imposed by the extent of the market. We claim that the degree of specialization is more often determined by other considerations. Especially emphasized are various costs of "coordinating" specialized workers who perform complementary tasks, and the amount of general knowledge available.