Quantifying the inefficiency of multi-unit auctions for normal goods

We study multi-unit auctions for perishable goods, in a setting where the supply arrives online. This is motivated by its application in advertisement auctions on the internet. We give a 1<over>4 -competitive algorithm for computing the optimal single price auction assuming that all the agents report their bids truthfully. We use that algorithm to develop a truthful auction with a constant competitive ratio compared to the optimum offline single-price auction.

Competition and Cooperation in Divisible Good Auctions: An Experimental Examination