A higher endowment of some good will typically cause an individual to place a lower value on increases (or decreases) in that endowment. This property, which we call diminishing marginal value, is a pervasive component of economists' beliefs about people's behavior. In ordinary markets "the more...

The idea that preferences are only revealed by real incentives is deeply embedded in economists' worldview. Consequently, evidence from hypothetical experiments has not readily permeated economic thinking. One method for determining whether hypothetical experiments provide useful information...