The Pareto optimality and price behavior of English and Dutch oral auctions, and First‐Price and Second‐Price sealedbid auctions are compared under various procedures for assigning valuations among cash motivated bidders. The Vickrey propositions with respect to the mean and variance of prices under the English, Dutch and Second‐Price auctions are not falsified by the data. Individual behavior and prices in the First‐Price auction deviates considerably from Vickrey's Nash postulate. Behaviorly, the English and Second‐Price auctions appear to be isomorphic, but the Dutch and First‐Price auctions may not be