We combine two experiments and a survey to measure trust and trustworthiness—two key components of social capital. Standard attitudinal survey questions about trust predict trustworthy behavior in our experiments much better than they predict trusting behavior. Trusting behavior in the experiments is predicted by past trusting behavior outside of the experiments. When individuals are closer socially, both trust and trustworthiness rise. Trustworthiness declines when partners are of different races or nationalities. High status individuals are able to elicit more trustworthiness in others.

We study price discrimination where consumers know at the time of contracting only the distribution of their valuations but subsequently learn their actual valuations. Consumers are sequentially screened, as in a menu of refund contracts. Initial valuation uncertainty can differ in terms of first-order stochastic dominance or mean-preserving-spread. In both cases, optimal mechanisms depend on informativeness of consumers' initial knowledge about their valuations, not on uncertainty that affects all consumers. It can be optimal to “subsidize” consumers with smaller valuation uncertainty through low refund to reduce the rent to those who face greater uncertainty and purchase more “flexible” contracts.

Title IV of the 1990 Clean Air Act Amendments (CAAA) established a market for transferable sulfur dioxide (SO2) emission allowances among electric utilities. This market offers firms facing high marginal abatement costs the opportunity to purchase the right to emit SO2 from firms with lower costs, and is expected to yield cost savings compared to a command and control approach to environmental regulation. This paper uses econometrically estimated marginal abatement cost functions for power plants affected by Title IV of the CAAA to evaluate the performance of the SO2 allowance market. Specifically, we investigate whether the much-heralded fall in the cost of abating SO2, compared to original estimates, can be attributed to allowance trading. We demonstrate that, for plants using low-sulfur coal to reduce SO2 emissions, technical changes and the fall in low-sulfur coal prices have lowered marginal abatement cost curves by over 50% since 1985. The flexibility to take advantage of these changes is the main source of cost reductions, rather than trading per se. In the long run, allowance trading may achieve cost savings of 700-800 million per year compared to an "enlightened" command and control program characterized by a uniform emission rate standard. The cost savings would be twice as great if the alternative to trading were forced scrubbing. However, a comparison of potential cost savings in 1995 and 1996 with actual emissions costs suggests that most trading gains were unrealized in the first two years of the program.