ACM Trans. Economics and Comput.最新文献

{"title":"Incentives, gamification, and game theory: an economic approach to badge design","authors":"D. Easley, Arpita Ghosh","doi":"10.1145/2482540.2482571","DOIUrl":"https://doi.org/10.1145/2482540.2482571","url":null,"abstract":"Gamification is growing increasingly prevalent as a means to incentivize user engagement of social media sites that rely on user contributions. Badges, or equivalent rewards such as top-contributor lists that are used to recognize a user's contributions on a site, clearly appear to be valued by users who actively pursue and compete for them. However, different sites use different badge designs, varying how, and for what, badges are awarded--- some sites such as StackOverflow award badges for meeting fixed levels of contribution, while others like Amazon and Y! Answers reward users for being amongst some top set of contributors on the site, corresponding to a competitive standard of performance. Given that users value badges, and that contributing to a site requires effort, how badges are designed will affect the incentives--- and therefore the participation and effort--- elicited from strategic users on a site.\u0000 We take a game-theoretic approach to badge design, analyzing the incentives created by widely-used badge designs in a model where winning a badge is valued and effort is costly, and potential contributors to the site endogenously decide whether or not to participate, and how much total effort to put into their contributions to the site. We analyze equilibrium existence, and equilibrium participation and effort in an absolute standards mechanism Mα where badges are awarded for meeting some absolute level of (observed) effort, and a relative standards mechanism Mρ corresponding to competitive standards as in a top-rs contributor badge. We find that equilibria always exist in both mechanisms, even when the value from winning a badge depends endogenously on the number of other winners. However, Mα has zero-participation equilibria for standards that are too high, whereas all equilibria in Mρ elicit non-zero participation for all possible ρ, provided ρ is specified as a fixed number rather than as a fraction of actual contributors (note that the two are not equivalent in a setting with endogenous participation). Finally, we ask whether or not a site should explicitly announce the number of users winning a badge; the answer to this question is determined by the curvature of the value of winning the badge as a function of the number of other winners.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125621705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"When do noisy votes reveal the truth?","authors":"I. Caragiannis, A. Procaccia, Nisarg Shah","doi":"10.1145/2482540.2482570","DOIUrl":"https://doi.org/10.1145/2482540.2482570","url":null,"abstract":"A well-studied approach to the design of voting rules views them as maximum likelihood estimators; given votes that are seen as noisy estimates of a true ranking of the alternatives, the rule must reconstruct the most likely true ranking. We argue that this is too stringent a requirement, and instead ask: How many votes does a voting rule need to reconstruct the true ranking? We define the family of pairwise-majority consistent rules, and show that for all rules in this family the number of samples required from the Mallows noise model is logarithmic in the number of alternatives, and that no rule can do asymptotically better (while some rules like plurality do much worse). Taking a more normative point of view, we consider voting rules that surely return the true ranking as the number of samples tends to infinity (we call this property accuracy in the limit); this allows us to move to a higher level of abstraction. We study families of noise models that are parametrized by distance functions, and find voting rules that are accurate in the limit for all noise models in such general families. We characterize the distance functions that induce noise models for which pairwise-majority consistent rules are accurate in the limit, and provide a similar result for another novel family of position-dominance consistent rules. These characterizations capture three well-known distance functions.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"27 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132273732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Truthfulness and Stochastic Dominance with Monetary Transfers","authors":"M. Hoefer, Thomas Kesselheim, Berthold Vöcking","doi":"10.1145/2847522","DOIUrl":"https://doi.org/10.1145/2847522","url":null,"abstract":"We consider truthfulness concepts for auctions with payments based on first- and second-order stochastic dominance. We assume bidders consider wealth in standard quasilinear form as valuation minus payments. Additionally, they are sensitive to risk in the distribution of wealth stemming from randomized mechanisms. First- and second-order stochastic dominance are well known to capture risk sensitivity, and we apply these concepts to capture truth-telling incentives for bidders.\u0000 As our first main result, we provide a complete characterization of all social-choice functions over binary single-parameter domains that can be implemented by a mechanism that is truthful in first- and second-order stochastic dominance. We show that these are exactly the social-choice functions implementable by truthful-in-expectation mechanisms, and we provide a novel payment rule that guarantees stochastic dominance. As our second main result we extend the celebrated randomized metarounding approach for truthful-in-expectation mechanisms in packing domains. We design mechanisms that are truthful in first-order stochastic dominance by spending only a logarithmic factor in the approximation guarantee.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123781784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to the Special Issue on Algorithmic Game Theory","authors":"M. Feldman, N. Nisan","doi":"10.1145/2465769.2465770","DOIUrl":"https://doi.org/10.1145/2465769.2465770","url":null,"abstract":"During the spring semester of 2011, we held a special semester on Algorithmic Game Theory (AGT) at the Institute for Advanced Studies at the Hebrew University of Jerusalem, Israel. The program brought together many of the key leading researchers in the field and reflected the excitement surrounding it. During the semester, a weekly seminar was held, featuring talks by members of the research group as well as additional guests. The culmination of the semester was marked by a week-long, well-attended workshop, which had wide coverage of AGT, excellent talks, and real community building. This special issue of TEAC is composed of invited papers that were presented during the special semester on AGT. Some of the talks can be found via the following link: http://www.cs.huji.ac.il/conferences/agt-semester/iagt2011/schedule.php We wish to thank the Institute for Advanced Studies at the Hebrew University for the wonderful opportunity to host such a great program. We also wish to thank all the fellows and visitors who made this semester a success with their presence.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"52 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132896705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Near-Potential Games: Geometry and Dynamics","authors":"Ozan Candogan, A. Ozdaglar, P. Parrilo","doi":"10.1145/2465769.2465776","DOIUrl":"https://doi.org/10.1145/2465769.2465776","url":null,"abstract":"Potential games are a special class of games for which many adaptive user dynamics converge to a Nash equilibrium. In this article, we study properties of near-potential games, that is, games that are close in terms of payoffs to potential games, and show that such games admit similar limiting dynamics.\u0000 We first focus on finite games in strategic form. We introduce a distance notion in the space of games and study the geometry of potential games and sets of games that are equivalent, with respect to various equivalence relations, to potential games. We discuss how, given an arbitrary game, one can find a nearby game in these sets. We then study dynamics in near-potential games by focusing on continuous-time perturbed best response dynamics. We characterize the limiting behavior of this dynamics in terms of the upper contour sets of the potential function of a close potential game and approximate equilibria of the game. Exploiting structural properties of approximate equilibrium sets, we strengthen our result and show that for games that are sufficiently close to a potential game, the sequence of mixed strategies generated by this dynamics converges to a small neighborhood of equilibria whose size is a function of the distance from the set of potential games.\u0000 In the second part of the article, we study continuous games and show that our approach for characterizing the limiting sets in near-potential games extends to continuous games. In particular, we consider continuous-time best response dynamics and a variant of it (where players update their strategies only if there is at least ε utility improvement opportunity) in near-potential games where the strategy sets are compact and convex subsets of a Euclidean space. We show that these update rules converge to a neighborhood of equilibria (or the maximizer of the potential function), provided that the potential function of the nearby potential game satisfies some structural properties. Our results generalize the known convergence results for potential games to near-potential games.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130360025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient Market Making via Convex Optimization, and a Connection to Online Learning","authors":"Jacob D. Abernethy, Yiling Chen, Jennifer Wortman Vaughan","doi":"10.1145/2465769.2465777","DOIUrl":"https://doi.org/10.1145/2465769.2465777","url":null,"abstract":"We propose a general framework for the design of securities markets over combinatorial or infinite state or outcome spaces. The framework enables the design of computationally efficient markets tailored to an arbitrary, yet relatively small, space of securities with bounded payoff. We prove that any market satisfying a set of intuitive conditions must price securities via a convex cost function, which is constructed via conjugate duality. Rather than deal with an exponentially large or infinite outcome space directly, our framework only requires optimization over a convex hull. By reducing the problem of automated market making to convex optimization, where many efficient algorithms exist, we arrive at a range of new polynomial-time pricing mechanisms for various problems. We demonstrate the advantages of this framework with the design of some particular markets. We also show that by relaxing the convex hull we can gain computational tractability without compromising the market institution’s bounded budget. Although our framework was designed with the goal of deriving efficient automated market makers for markets with very large outcome spaces, this framework also provides new insights into the relationship between market design and machine learning, and into the complete market setting. Using our framework, we illustrate the mathematical parallels between cost-function-based markets and online learning and establish a correspondence between cost-function-based markets and market scoring rules for complete markets.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121166438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selling in Exclusive Markets: Some Observations on Prior-Free Mechanism Design","authors":"Anna R. Karlin, C. T. Nguyen, Y. Peres","doi":"10.1145/2465769.2465772","DOIUrl":"https://doi.org/10.1145/2465769.2465772","url":null,"abstract":"We consider prior-free benchmarks in non-matroid settings. In particular, we show that a very desirable benchmark proposed by Hartline and Roughgarden is too strong, in the sense that no truthful mechanism can compete with it even in a very simple non-matroid setting where there are two exclusive markets and the seller can only sell to agents in one of them. On the other hand, we show that there is a mechanism that competes with a symmetrized version of this benchmark. We further investigate the more traditional best fixed price profit benchmark and show that there are mechanisms that compete with it in any downward-closed settings.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"229 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131496235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The ACM transactions on economics and computation: An introduction","authors":"Vincent Conitzer, R. McAfee","doi":"10.1145/2399187.2399188","DOIUrl":"https://doi.org/10.1145/2399187.2399188","url":null,"abstract":"We are very excited to present this first issue of the ACM Transactions on Economics and Computation (TEAC). This journal has been several years in the making, with the original proposal submitted to ACM in September 2010, and it has been wonderful to watch the evolution from an idea to a journal with articles in print. We believe the timing of the journal is excellent, because research in the intersection of computer science and economics is booming. A number of universities now have centers or programs in this area, and tech giants such as Google and Microsoft also have teams of top-tier researchers that truly span the different disciplines. The US National Science Foundation (NSF) recently started a new program on the Interface between Computer Science and Economics & Social Sciences (ICES). Similar research is also funded by other agencies inside and outside the United States.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126237001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A game-theoretic analysis of the ESP game","authors":"Shaili Jain, D. Parkes","doi":"10.1145/2399187.2399190","DOIUrl":"https://doi.org/10.1145/2399187.2399190","url":null,"abstract":"“Games with a Purpose” are interactive games that users play because they are fun, with the added benefit that the outcome of play is useful work. The ESP game, developed byy von Ahn and Dabbish [2004], is an example of such a game devised to label images on the web. Since labeling images is a hard problem for computer vision algorithms and can be tedious and time-consuming for humans, the ESP game provides humans with incentive to do useful work by being enjoyable to play. We present a simple game-theoretic model of the ESP game and characterize the equilibrium behavior in our model. Our equilibrium analysis supports the fact that users appear to coordinate on low effort words. We provide an alternate model of user preferences, modeling a change that could be induced through a different scoring method, and show that equilibrium behavior in this model coordinates on high-effort words. We also give sufficient conditions for coordinating on high-effort words to be a Bayesian-Nash equilibrium. Our results suggest the possibility of formal incentive design in achieving desirable system-wide outcomes for the purpose of human computation, complementing existing considerations of robustness against cheating and human factors.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133949048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal payments in dominant-strategy mechanisms for single-parameter domains","authors":"V. Naroditskiy, M. Polukarov, N. Jennings","doi":"10.1145/2399187.2399191","DOIUrl":"https://doi.org/10.1145/2399187.2399191","url":null,"abstract":"We study dominant-strategy mechanisms in allocation domains where agents have one-dimensional types and quasilinear utilities. Taking an allocation function as an input, we present an algorithmic technique for finding optimal payments in a class of mechanism design problems, including utilitarian and egalitarian allocation of homogeneous items with nondecreasing marginal costs. Our results link optimality of payment functions to a geometric condition involving triangulations of polytopes. When this condition is satisfied, we constructively show the existence of an optimal payment function that is piecewise linear in agent types.","PeriodicalId":194623,"journal":{"name":"ACM Trans. Economics and Comput.","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132629225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}