Proceedings of the fifteenth ACM conference on Economics and computation最新文献

{"title":"Dynamically eliciting unobservable information","authors":"Christopher P. Chambers, Nicolas S. Lambert","doi":"10.1145/2600057.2602859","DOIUrl":"https://doi.org/10.1145/2600057.2602859","url":null,"abstract":"We answer the following question: At $t=1$, an expert has (probabilistic) information about a random outcome X. In addition, the expert will obtain further information about $X$ as time passes, up to some time t=T+1 at which X will be publicly revealed. (How) Can a protocol be devised that induces the expert, as a strict best response, to reveal at the outset his prior assessment of both X and the information flows he anticipates and, subsequently, what information he privately receives' (The protocol can provide the expert with payoffs that depend only on the realization of X, as well as any decisions he may take.) We show that this can be done with the following sort of protocol: At the penultimate time t=T, the expert chooses a payoff function from a menu of such functions, where the menu available to him was chosen by him at time $t=T-1$ from a menu of such menus, and so forth. We show that any protocol that affirmatively answers our question can be approximated by a protocol of the form described. We show how these results can be extended from discrete time to continuous time problems of this sort.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134207602","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 general volume-parameterized market making framework","authors":"Jacob D. Abernethy, Rafael M. Frongillo, Xiaolong Li, Jennifer Wortman Vaughan","doi":"10.1145/2600057.2602900","DOIUrl":"https://doi.org/10.1145/2600057.2602900","url":null,"abstract":"We introduce a framework for automated market making for prediction markets, the volume parameterized market (VPM), in which securities are priced based on the market maker's current liabilities as well as the total volume of trade in the market. We provide a set of mathematical tools that can be used to analyze markets in this framework, and show that many existing market makers (including cost-function based markets [Chen and Pennock 2007; Abernethy et al. 2011, 2013], profit-charging markets [Othman and Sandholm 2012], and buy-only markets [Li and Vaughan 2013]) all fall into this framework as special cases. Using the framework, we design a new market maker, the perspective market, that satisfies four desirable properties (worst-case loss, no arbitrage, increasing liquidity, and shrinking spread) in the complex market setting, but fails to satisfy information incorporation. However, we show that the sacrifice of information incorporation is unavoidable: we prove an impossibility result showing that any market maker that prices securities based only on the trade history cannot satisfy all five properties simultaneously. Instead, we show that perspective markets may satisfy a weaker notion that we call center-price information incorporation.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"25 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134544912","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":"Removing arbitrage from wagering mechanisms","authors":"Yiling Chen, Nikhil R. Devanur, David M. Pennock, Jennifer Wortman Vaughan","doi":"10.1145/2600057.2602876","DOIUrl":"https://doi.org/10.1145/2600057.2602876","url":null,"abstract":"We observe that Lambert et al.'s [2008] family of weighted score wagering mechanisms admit arbitrage: participants can extract a guaranteed positive payoff by betting on any prediction within a certain range. In essence, participants leave free money on the table when they ``agree to disagree,'' and as a result, rewards don't necessarily go to the most informed and accurate participants. This observation suggests that when participants have immutable beliefs, it may be possible to design alternative mechanisms in which the center can make a profit by removing this arbitrage opportunity without sacrificing incentive properties such as individual rationality, incentive compatibility, and sybilproofness. We introduce a new family of wagering mechanisms called no-arbitrage wagering mechanisms that retain many of the positive properties of weighted score wagering mechanisms, but with the arbitrage opportunity removed. We show several structural results about the class of mechanisms that satisfy no-arbitrage in conjunction with other properties, and provide examples of no-arbitrage wagering mechanisms with interesting properties.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123151323","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":"Whole page optimization: how page elements interact with the position auction","authors":"Pavel Metrikov, Fernando Diaz, Sébastien Lahaie, Justin M. Rao","doi":"10.1145/2600057.2602871","DOIUrl":"https://doi.org/10.1145/2600057.2602871","url":null,"abstract":"We study the trade-off between layout elements of the search results page and revenue in the real-time sponsored search auction. Using data from a randomized experiment on a major search engine, we find that having images present among the search results tends to simultaneously raise the ad click-through rate and flatten the ad click curve, reducing the premium for occupying the top slot and thus impacting bidding incentives. Theoretical analysis shows that this type of change creates an ambiguous impact on revenue in equilibrium: a steeper curve with lower total click-through rate is preferable only if the expected revenue distribution is skewed enough towards the top bidder. Empirically, we show that this is a relatively rare phenomenon, and we also find that whole page satisfaction causally raises the click-through rate of the ad block. This means search engines have a short-run incentive to boost search result quality, not just a long-run incentive based on competition between providers.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"50 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126443060","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":"Neutrality and geometry of mean voting","authors":"Sébastien Lahaie, Nisarg Shah","doi":"10.1145/2600057.2602898","DOIUrl":"https://doi.org/10.1145/2600057.2602898","url":null,"abstract":"Mean proximity rules provide a simple geometric framework to achieve consensus among a collection of rankings (votes) over a set of alternatives. They embed all rankings into a Euclidean space, take the mean of the embeddings of the input votes, and return the ranking whose embedding is closest to the mean. Previous work on mean proximity rules has not integrated an important axiom---neutrality---into the framework. By drawing on ideas from the representation theory of finite groups, we show that integrating neutrality actually helps achieve a succinct representation for every mean proximity rule. Various connections are drawn between mean proximity rules and other prominent approaches to social choice.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126538195","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":"Extensive-form game abstraction with bounds","authors":"Christian Kroer, T. Sandholm","doi":"10.1145/2600057.2602905","DOIUrl":"https://doi.org/10.1145/2600057.2602905","url":null,"abstract":"Abstraction has emerged as a key component in solving extensive-form games of incomplete information. However, lossless abstractions are typically too large to solve, so lossy abstraction is needed. All prior lossy abstraction algorithms for extensive-form games either 1) had no bounds on solution quality or 2) depended on specific equilibrium computation approaches, limited forms of abstraction, and only decreased the number of information sets rather than nodes in the game tree. We introduce a theoretical framework that can be used to give bounds on solution quality for any perfect-recall extensive-form game. The framework uses a new notion for mapping abstract strategies to the original game, and it leverages a new equilibrium refinement for analysis. Using this framework, we develop the first general lossy extensive-form game abstraction method with bounds. Experiments show that it finds a lossless abstraction when one is available and lossy abstractions when smaller abstractions are desired. While our framework can be used for lossy abstraction, it is also a powerful tool for lossless abstraction if we set the bound to zero. Prior abstraction algorithms typically operate level by level in the game tree. We introduce the extensive-form game tree isomorphism and action subset selection problems, both important problems for computing abstractions on a level-by-level basis. We show that the former is graph isomorphism complete, and the latter NP-complete. We also prove that level-by-level abstraction can be too myopic and thus fail to find even obvious lossless abstractions.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127560814","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":"Pragmatic algorithmic game theory","authors":"Kevin Leyton-Brown","doi":"10.1145/2600057.2602959","DOIUrl":"https://doi.org/10.1145/2600057.2602959","url":null,"abstract":"Algorithmic Game Theory (AGT) studies problems at the interface between computer science and microeconomics. Research in this area typically attacks very general settings using theoretical tools. There are great advantages to such an approach: in particular, the field has amassed an impressive range of sweeping impossibility, optimality, and approximation results. However, sometimes it is very difficult to obtain a clean theoretical result that addresses a complex, real-world problem of interest. We can often say more about realistic problems if we're willing to be pragmatic. In particular, progress can often be made by leveraging one or both of the following forms of pragmatism: 1. Aiming to achieve good performance only on problems of interest, rather than in relatively unconstrained settings; and 2. Working with statistical rather than analytical tools, thereby defining problems of interest implicitly via a dataset and/or appealing to data-driven measures of performance. This talk will survey three broad problems that I have attacked using such pragmatic approaches in my own research. (There is, of course, a wide range of excellent work in this vein by others; however, surveying it is beyond the scope of this talk.) First, a central problem in AGT is reasoning about equilibrium behavior in games. A seminal result was that the identification of a sample Nash equilibrium is PPAD-complete even in two-player games, meaning that the problem is probably intractable in the worst case. However, it is nevertheless often still possible to reason about games of interest, because they often exhibit various structural regularities. I'll describe the Action Graph Game (AGG) formalism, and explain how restricting ourselves to games that are compact in this (general) language yields exponential performance improvements. AGGs are particularly interesting for AGT researchers because they can compactly model messy, realistic mechanisms like advertising auctions or voting systems. I'll discuss what can be gained by analyzing such mechanisms in this way, and introduce some general tools that researchers can use to easily leverage these techniques in their own work. A second problem at the core of AGT is market design. I'll focus here on the FCC's upcoming 'incentive auction', in which television broadcasters will be given the opportunity to sell their broadcast rights, remaining broadcasters will be repacked into a smaller block of spectrum, and the freed airwaves will be resold to telecom companies. The stakes for this auction are huge'projected tens of billions of dollars in revenue for the government'justifying the design of a special-purpose descending-price auction mechanism, which I'll describe. An inner-loop problem in this mechanism is determining whether a given set of broadcasters can be repacked into a smaller block of spectrum while respecting radio interference constraints. This is an instance of a (worst-case intractable) graph coloring problem; howe","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122881089","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 voting via the top-k elicitation scheme: a probabilistic approach","authors":"Yuval Filmus, J. Oren","doi":"10.1145/2600057.2602829","DOIUrl":"https://doi.org/10.1145/2600057.2602829","url":null,"abstract":"Top-i voting is a common form of preference elicitation due to its conceptual simplicity both on the voters' side and on the decision maker's side. In a typical setting, given a set of candidates, the voters are required to submit only the k-length prefixes of their intrinsic rankings of the candidates. The decision maker then tries to correctly predict the winning candidate with respect to the complete preference profile according to a prescribed voting rule. This raises a tradeoff between the communication cost (given the specified value of k), and the ability to correctly predict the winner. We focus on arbitrary positional scoring rules in which the voters' scores for the candidates is given by a vector that assigns the ranks real values. We study the performance of top-k elicitation under three probabilistic models of preference distribution: a neutral distribution (impartial culture); a biased distribution, such as the Mallows distribution; and a worst-case (but fully known) distribution. For an impartial culture, we provide a technique for analyzing the performance of top-k voting. For the case of arbitrary positional scoring rules, we provide a succinct set of criteria that is sufficient for obtaining both lower and upper bounds on the minimal k necessary to determine the true winner with high probability. Our lower bounds pertain to any implementation of a top-k voting scheme, whereas for our upper bound, we provide a concrete top-k elicitation algorithm. We further demonstrate the use of this technique on Copeland's voting rule. For the case of biased distributions, we show that for any non-constant scoring rule, the winner can be predicted with high probability without ever looking at the votes. For worst-case distributions, we show that for exponentially decaying scoring rules, k = O(log m) is sufficient for all distributions.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"4 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132935157","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":"Fair enough: guaranteeing approximate maximin shares","authors":"A. Procaccia, Junxing Wang","doi":"10.1145/2600057.2602835","DOIUrl":"https://doi.org/10.1145/2600057.2602835","url":null,"abstract":"We consider the problem of fairly allocating indivisible goods, focusing on a recently-introduced notion of fairness called maximin share guarantee: Each player's value for his allocation should be at least as high as what he can guarantee by dividing the items into as many bundles as there are players and receiving his least desirable bundle. Assuming additive valuation functions, we show that such allocations may not exist, but allocations guaranteeing each player 2/3 of the above value always exist, and can be computed in polynomial time when the number of players is constant. These theoretical results have direct practical implications.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128429013","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":"Deferred-acceptance auctions and radio spectrum reallocation","authors":"Paul R. Milgrom, I. Segal","doi":"10.1145/2600057.2602834","DOIUrl":"https://doi.org/10.1145/2600057.2602834","url":null,"abstract":"Deferred-acceptance auctions choose allocations by an iterative process of rejecting the least attractive bid. These auctions have distinctive computational and incentive properties that make them suitable for application in some challenging environments, such as the planned US auction to repurchase television broadcast rights. For any set of values, any deferred acceptance auction with “threshold pricing”is weakly group strategy-proof, can be implemented using a clock auction, and leads to the same outcome as the complete-information Nash equilibrium of the corresponding paid-as-bid auction. A paid-asbid auction with a non-bossy bid-selection rule is dominance solvable if and only if it is a deferred acceptance auction. ∗The authors thank Alexey Kushnir as well as Mohammad Akbarpour, Piotr Dworczak, Tim Roughgarden, Inbal Talgam Cohen, Joshua Thurston-Milgrom, and Alex Wolitzky for their comments and suggestions. †Department of Economics, Stanford University, Stanford, CA 94305. The authors are members of the Auctionomics’team advising the US Federal Communications Commission concerning the design of the US “incentive auction.”This research analyzes some properties of proposals to which the authors have contributed. ‡Segal gratefully acknowledges the support of the Toulouse Network for Information Technology.","PeriodicalId":203155,"journal":{"name":"Proceedings of the fifteenth ACM conference on Economics and computation","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127775306","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}