Abstract: A competitive economy is studied in which sellers offer alternative direct mechanisms to buyers who have private information about their own private use value for the commodity being traded. In addition the commodity has a common value to all buyers, perhaps represented by the future resale value of the commodity. A competitive equilibrium in mechanisms is described. In every such equilibrium it is shown that sellers must offer mechanisms that are allocationally equivalent to English ascending price auctions. The reservation prices that sellers set are equal to the ex post value of a 'marginal' unsold unit. This value is below the ex post opportunity cost to the seller of trading the commodity.
JEL Classification: D82;D83;D44