This study presents a laboratory experiment of the first and second price sealed bid auctions with independent private values, where the distribution of bidder valuations is unknown. In our experimental setting, in first price auctions, bids are lower with the presence of ambiguity. This result...

I show that in a private value multi-unit uniform-price auction, the reservation price increases both the efficiency and revenue. In equilibrium the difference between the true value of a unit and the submitted bid (shading) is different for each unit; therefore, the seller cannot allocate units...