Revenue-equivalence of competitive and discriminatory formats is a major result for private-value multiunit auctions with risk-neutral bidders. Among the factors that may cause this result to break down, the most notorious ones are risk-aversion, value-affiliation, and endogenous bidder participation. Using data from competitive and discriminatory auctions undertaken in the Zambian foreign exchange market, the author analyzes revenue-equivalence and other bidding phenomena. The results indicate that (1) competitive auctions were revenue-superior due to higher participation; (2) high bidders adjusted with delay to an auction format change; and (3) a reservation bid was used as a policy instrument. Copyright 1993 by MIT Press.

We use information from the television game show with the highest guaranteed average payoff in the United States, Hoosier Millionaire, to analyze risktaking in a high-stakes experiment. We characterize gambling decisions under alternative assumptions about contestant behavior and preferences, and derive testable restrictions on individual risk attitudes based on this characterization. We then use an extensive sample of gambling decisions to estimate distributions of risk-aversion parameters consistent with the theoretical restrictions and revealed preferences. We find that although most contestants display risk-averse preferences, the extent of the risk aversion implied by our estimates varies substantially with the stakes involved in the different decisions.