This is a presentation of the paper "Competitive Generalized Auctions" by Jason Hartline, Amos Fiat, Andrew Goldberg, and Anna Karlin, STOC 2002.
The authors describe mechanisms for auctions that are truthful while guaranteeing no net loss in profit (to the auctioneer). One such concept is of being able to cancel an auction. These cancelable auctions have the property that if the revenue collected does not meet a certain predetermined criteria, then the auction can be cancelled and still remain truthful. My talk will focus on these cancelable auctions.