Christopher A. Wilkens

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We present algorithms for a class of resource allocation problems both in the online setting with stochastic input and in the offline setting. This class of problems contains many interesting special cases such as the Adwords problem. In the online setting we introduce a new distributional model called the adversarial stochastic input model, which is a(More)
Truthfulness is fragile and demanding. It is oftentimes harder to guarantee truthfulness when solving a problem than it is to solve the problem itself. Even worse, truthfulness can be utterly destroyed by small uncertainties in a mechanism’s outcome. One obstacle is that truthful payments depend on outcomes other than the one realized, such as the(More)
Economics and Computation: Ad Auctions and Other Stories by Christopher A. Wilkens Doctor of Philosophy in Computer Science University of California, Berkeley Professor Christos H. Papadimitriou, Chair There is a growing research tradition in the interface between Economics and Computer Science: Economic insights and questions about incentives inform the(More)
A single advertisement often benefits many parties, for example, an ad for a Samsung laptop benefits Microsoft. We study this phenomenon in search advertising auctions and show that standard solutions, including the status quo ignorance of mutual benefit and a benefit-aware Vickrey-Clarke-Groves mechanism, perform poorly. In contrast, we show that an(More)
The generalized second price (GSP) auction has served as the core selling mechanism for sponsored search ads for over a decade. However, recent trends expanding the set of allowed ad formats—to include a variety of sizes, decorations, and other distinguishing features—have raised critical problems for GSP-based platforms. Alternatives such as the(More)
We study the optimal mechanism design problem faced by a market intermediary who makes revenue by connecting buyers and sellers. We first show that the optimal intermediation protocol has substantial structure: it is the solution to an algorithmic pricing problem in which seller’s costs are replaced with virtual costs, and the sellers’ payments need only(More)
The convexity assumptions required for the Arrow-Debreu theorem are reasonable and realistic for preferences; however, they are highly problematic for production because they rule out economies of scale. We take a complexity-theoretic look at economies with non-convex production. It is known that in such markets equilibrium prices may not exist; we show(More)
The popular generalized second price (GSP) auction for sponsored search is built upon a separable model of click-through-rates that decomposes the likelihood of a click into the product of a “slot effect” and an “advertiser effect”—if the first slot is twice as good as the second for some bidder, then it is twice as good for everyone. Though appealing in(More)
Bidders often want to get as much as they can without violating constraints on what they spend. For example, advertisers seek to maximize the impressions, clicks, sales, or market share generated by their advertising, subject to budget or return-on-investment (ROI) constraints. Likewise, when bidders have no direct utility for leftover money – e.g., because(More)