We investigate search engines ’ mechanism for allocating impressions generated from different search terms. This mechanism is equivalent to running an independent GSP auction for each search term only when the number of search terms is small. In practice, the number of search terms is so large that an advertiser cannot possibly communicate to the search engine all the GSP auctions that he wishes to participate in. For example, a travel agency is interested in all search terms pertaining to flight, including “flight to boston”, “ticket to SFO”, “cheap airfare”, etc. Therefore, the search engine introduces broad match keywords as a bidding language that allows an advertiser to submit a bid for multiple GSP auctions at once. However, with broad match

We present the first monotone randomized polynomial-time approximation scheme (PTAS) for minimizing the makespan of parallel related machines ($Q||C_{\max}$), the paradigmatic problem in single-parameter algorithmic mechanism design. This result immediately gives a polynomial-time, truthful (in expectation) mechanism whose approximation guarantee attains the best-possible one for all polynomial-time algorithms (assuming $P\neq NP$). Our algorithmic techniques are flexible and also yield a monotone deterministic quasi-PTAS for $Q||C_{\max}$ and a monotone randomized PTAS for max-min scheduling on related machines.

We design and analyze approximately revenue-maximizing auctions in general single-parameter settings. Bidders have publicly observable attributes, and we assume that the valuations of indistinguishable bidders are independent draws from a common distribution. Crucially, we assume all valuation distributions are a priori unknown to the seller. Despite this handicap, we show how to obtain approximately optimal expected revenue - nearly as large as what could be obtained if the distributions were known in advance - under quite general conditions.

We present the first monotone randomized polynomial-time approximation scheme (PTAS) for minimizing the makespan of parallel related machines (Q||Cmax), the paradigmatic problem in single-parameter algorithmic mechanism design. This result immediately gives a polynomial-time, truthful (in expectation) mechanism whose approximation guarantee attains the best-possible one for all polynomial-time algorithms (assuming P not equal to NP). Our algorithmic techniques are flexible and also yield, among other results, a monotone deterministic quasi-PTAS for Q||Cmaxand a monotone randomized PTAS for max-min scheduling on related machines.