Because of their numerous applications, e.g., sales of U.S. Treasury bills and spectrum licenses, multi unit auctions have attracted the interest of practitioners and economists. There is a need to identify practical, multi unit mechanisms that implement efficient outcomes and generate high seller's revenues in various environments. Recently, Ausubel (1997) defined a dynamic, open, ascending price auction and demonstrated that it has several advantages over many commonly used multi unit mechanisms: it produces efficient allocations and generates higher revenues. In addition, the new ascending price auction is simple and sufficiently appealing to be of practical use. The ascending price auction and the well known Vickrey auction are compared experimentally to test whether the predicted advantages of the new multi unit mechanism are realized in practiced. The relative performance of both auctions is evaluated in terms of efficiency and revenue. Experimental regularities in the performance of the mentioned mechanisms can contribute to the development and implementation of more adequate trading institutions.
