Michael Ostrovsky

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We investigate the “generalized second price” auction (GSP), a new auction mechanism, which is used by Internet search engines to sell online advertising. GSP is tailored to its unique environment, and neither the mechanism nor the environment have previously been studied in the auction literature. Although GSP looks similar to the Vickrey auction, its(More)
We examine prior and current sponsored search auctions and find evidence of strategic bidder behavior. Between June 15, 2002, and June 14, 2003, we estimate that Overture’s revenue from sponsored search could have been more than 60% higher if it had been able to prevent this strategic behavior. We also show that advertisers’ strategic behavior has not(More)
We consider truthful implementation of the socially efficient allocation in an independent private-value environment in which agents receive private information over time. We propose a suitable generalization of the pivot mechanism, based on the marginal contribution of each agent. In the dynamic pivot mechanism, the ex post incentive and ex post(More)
We estimate parameters from data on discrete dynamic games, using entry/exit games to illustrate. Semiparametric first-stage estimates of entry and continuation values are computed from sample averages of the realized continuation values of entrants and incumbents. Under certain assumptions, these values are easy-to-compute analytic functions of the(More)
We measure how the bundling of television channels affects short-run social welfare. We estimate an industry model of viewership, demand, pricing, bundling, and input market bargaining using data on ratings, purchases, prices, bundle composition, and aggregate input costs. We conduct counterfactual simulations of à la carte policies that require(More)
The woollen coat, for example, which covers the day-labourer, as coarse and rough as it may appear, is the produce of the joint labour of a great multitude of workmen. The shepherd, the sorter of the wool, the wool-comber or carder, the dyer, the scribbler, the spinner, the weaver, the fuller, the dresser, with many others, must all join their different(More)
The random priority (random serial dictatorship) mechanism is a common method for assigning objects to individuals. The mechanism is easy to implement and strategy-proof. However this mechanism is inefficient, as the agents may be made all better off by another mechanism that increases their chances of obtaining more preferred objects. Such an inefficiency(More)
We introduce a model in which agents in a network can trade via bilateral contracts. We find that when continuous transfers are allowed and utilities are quasilinear, the full substitutability of preferences is sufficient to guarantee the existence of stable outcomes for any underlying network structure. Furthermore, the set of stable outcomes is(More)