Proceedings of the 22nd ACM Conference on Economics and Computation最新文献_第3页

Fulfillment by Platform: Antitrust and Upstream Market Power 平台履约:反垄断与上游市场力量

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-07-18 DOI: 10.1145/3465456.3467564

Amandeep Singh, Jiding Zhang, Senthil K. Veeraraghavan

引用次数: 2

Voting by Simultaneous Vetoes 同时否决投票

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-07-18 DOI: 10.1145/3465456.3467557

Margarita Kirneva, Matías Núñez

{"title":"Voting by Simultaneous Vetoes","authors":"Margarita Kirneva, Matías Núñez","doi":"10.1145/3465456.3467557","DOIUrl":"https://doi.org/10.1145/3465456.3467557","url":null,"abstract":"Voting mechanisms often exhibit a large multiplicity of equilibria. In many of these equilibria, coordination failures among voters arise where some (coalition of) voters could have induced an outcome that they all prefer to the equilibrium outcome had they agreed on a common strategy. In order to prevent these failures, we study voting mechanisms requiring that every Nash equilibrium is coalition-proof ([1]) so that, in equilibrium, no coalition of voters has some mutually beneficial deviation. The described mechanisms achieve coalitional implementation, that is they implement social choice rules in both Nash and in coalition-proof equilibria. Our approach assumes complete information and is hence well-suited for voting mechanisms for small committees. We consider a committee of n voters selecting one out of k alternatives. The main focus of the paper is on the case with k > n which is a natural environment for a small committee. The first part of the paper considers the simultaneous veto (SV) mechanisms. In each of these mechanisms, each voter has the right to select a list of alternatives to veto, and the outcome is selected randomly from the nonvetoed alternatives. Each such equilibrium admits a pure strategy equilibrium for each preference profile assuming that voters' preferences over lotteries satisfy the mild assumption of stochastic dominance. In equilibrium, no pair of voters veto the same alternative. As we show, for each specification of the veto rights, each of these mechanisms coalitionally implements a Veto by random priority rule (VRP) introduced by [6].","PeriodicalId":395676,"journal":{"name":"Proceedings of the 22nd ACM Conference on Economics and Computation","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128106482","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}

引用次数: 0

Transaction Fee Mechanism Design 交易费用机制设计

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-07-18 DOI: 10.1145/3465456.3467591

T. Roughgarden

{"title":"Transaction Fee Mechanism Design","authors":"T. Roughgarden","doi":"10.1145/3465456.3467591","DOIUrl":"https://doi.org/10.1145/3465456.3467591","url":null,"abstract":"Demand for blockchains such as Bitcoin and Ethereum is far larger than supply, necessitating a mechanism that selects a subset of transactions to include \"on-chain\" from the pool of all pending transactions. EIP-1559 is a proposal to make several tightly coupled changes to the Ethereum blockchain's transaction fee mechanism, including the introduction of variable-size blocks and a burned base fee that rises and falls with demand. These changes are slated for deployment in Ethereum's \"London fork,\" scheduled for late summer 2021, at which point it will be the biggest economic change made to a major blockchain to date. The first goal of this paper is to formalize the problem of designing a transaction fee mechanism, taking into account the many idiosyncrasies of the blockchain setting (ranging from off-chain collusion between miners and users to the ease of money-burning). The second goal is to situate the specific mechanism proposed in EIP-1559 in this framework and rigorously interrogate its game-theoretic properties. The third goal is to suggest competing designs that offer alternative sets of trade-offs. The final goal is to highlight research opportunities for the EC community that could help shape the future of blockchain transaction fee mechanisms.","PeriodicalId":395676,"journal":{"name":"Proceedings of the 22nd ACM Conference on Economics and Computation","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122521837","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}

引用次数: 10

Matching and Money 配对与金钱

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-07-18 DOI: 10.1145/3465456.3467587

Ravi Jagadeesan, A. Teytelboym

引用次数: 0

Selling to a Group 向团体销售

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-07-18 DOI: 10.1145/3465456.3467569

Nima Haghpanah, Elliot Lipnowski

引用次数: 1

Proof-of-Stake Mining Games with Perfect Randomness 具有完全随机性的权益证明采矿游戏

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-07-08 DOI: 10.1145/3465456.3467636

Matheus V. X. Ferreira, S. Weinberg

{"title":"Proof-of-Stake Mining Games with Perfect Randomness","authors":"Matheus V. X. Ferreira, S. Weinberg","doi":"10.1145/3465456.3467636","DOIUrl":"https://doi.org/10.1145/3465456.3467636","url":null,"abstract":"Proof-of-Stake blockchains based on a longest-chain consensus protocol are an attractive energy-friendly alternative to the Proof-of-Work paradigm. However, formal barriers to \"getting the incentives right\" were recently discovered, driven by the desire to use the blockchain itself as a source of pseudorandomness. We consider instead a longest-chain Proof-of-Stake protocol with perfect, trusted, external randomness (e.g. a randomness beacon). We produce two main results. First, we show that a strategic miner can strictly outperform an honest miner with just 32.8% of the total stake. Note that a miner of this size cannot outperform an honest miner in the Proof-of-Work model. This establishes that even with access to a perfect randomness beacon, incentives in Proof-of-Work and Proof-of-Stake longest-chain protocols are fundamentally different. Second, we prove that a strategic miner cannot outperform an honest miner with 30.8% of the total stake. This means that, while not quite as secure as the Proof-of-Work regime, desirable incentive properties of Proof-of-Work longest-chain protocols can be approximately recovered via Proof-of-Stake with a perfect randomness beacon. The space of possible strategies in a Proof-of-Stake mining game is significantly richer than in a Proof-of-Work game. Our main technical contribution is a characterization of potentially optimal strategies for a strategic miner, and in particular a proof that the corresponding infinite-state MDP admits an optimal strategy that is positive recurrent.","PeriodicalId":395676,"journal":{"name":"Proceedings of the 22nd ACM Conference on Economics and Computation","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130671166","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}

引用次数: 13

Graphical Economies with Resale 转售的图形经济

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-06-28 DOI: 10.1145/3465456.3467628

G. Andrade, Rafael M. Frongillo, Elliot Gorokhovsky, Sharadha Srinivasan

引用次数: 3

Polarization in Geometric Opinion Dynamics 几何意见动力学中的两极分化

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-06-23 DOI: 10.1145/3465456.3467633

J. Gaitonde, J. Kleinberg, É. Tardos

{"title":"Polarization in Geometric Opinion Dynamics","authors":"J. Gaitonde, J. Kleinberg, É. Tardos","doi":"10.1145/3465456.3467633","DOIUrl":"https://doi.org/10.1145/3465456.3467633","url":null,"abstract":"In light of increasing recent attention to political polarization, understanding how polarization can arise poses an important theoretical question. While more classical models of opinion dynamics seem poorly equipped to study this phenomenon, a recent novel approach by Hka zł a, Jin, Mossel, and Ramnarayan (HJMR) proposes a simple geometric model of opinion evolution that provably exhibits strong polarization in specialized cases. Moreover, polarization arises quite organically in their model: in each time step, each agent updates opinions according to their correlation/response with an issue drawn at random. However, their techniques do not seem to extend beyond a set of special cases they identify, which benefit from fragile symmetry or contractiveness assumptions, leaving open how general this phenomenon really is. In this paper, we further the study of polarization in related geometric models. We show that the exact form of polarization in such models is quite nuanced: even when strong polarization does not hold, it is possible for weaker notions of polarization to nonetheless attain. We provide a concrete example where weak polarization holds, but strong polarization provably fails. However, we show that strong polarization provably holds in many variants of the HJMR model, which are also robust to a wider array of distributions of random issues---this suggests that the form of polarization introduced by HJMR is more universal than suggested by their special cases. We also show that the weaker notions connect more readily to the theory of Markov chains on general state spaces.","PeriodicalId":395676,"journal":{"name":"Proceedings of the 22nd ACM Conference on Economics and Computation","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131949023","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}

引用次数: 16

On Simple Mechanisms for Dependent Items 关于依赖项的简单机制

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-06-21 DOI: 10.1145/3465456.3467643

Yang Cai, Argyris Oikonomou

{"title":"On Simple Mechanisms for Dependent Items","authors":"Yang Cai, Argyris Oikonomou","doi":"10.1145/3465456.3467643","DOIUrl":"https://doi.org/10.1145/3465456.3467643","url":null,"abstract":"We study the problem of selling n heterogeneous items to a single buyer, whose values for different items are dependent. Under arbitrary dependence, Hart and Nisan[30] show that no simple mechanism can achieve a non-negligible fraction of the optimal revenue even with only two items. We consider the setting where the buyer's type is drawn from a correlated distribution that can be captured by a Markov Random Field, one of the most prominent frameworks for modeling high-dimensional distributions with structure. If the buyer's valuation is additive or unit-demand, we extend the result to all MRFs and show that $maxsrev,brev $ can achieve an Ømega(1/eO(Δ))-fraction of the optimal revenue, where Δ is a parameter of the MRF that is determined by how much the value of an item can be influenced by the values of the other items. We further show that the exponential dependence on Δ is unavoidable for our approach and a polynomial dependence on Δ is unavoidable for any approach. When the buyer has a XOS valuation, we show that max(SRev,BRev) achieves at least an $Ømega(1/eO(Δ) + 1/√nγ)-fraction of the optimal revenue, where γ is the spectral gap of the Glauber dynamics of the MRF. Note that the values of Δ and 1/nγ increase as the dependence between items strengthens. In the special case of independently distributed items, Δ=0 and 1/nγ ≥ 1, and our results recover the known constant factor approximations for a XOS buyer[41]. We further extend our parametric approximation to several other well-studied dependency measures such as the Dobrushin coefficient [27] and the inverse temperature. In particular, we show that if the MRF is in the high temperature regime, max(SRev,BRev) is still a constant factor approximation to the optimal revenue even for a XOS buyer. Our results are based on the Duality-Framework by Cai et al.[14] and a new concentration inequality for XOS functions over dependent random variables.","PeriodicalId":395676,"journal":{"name":"Proceedings of the 22nd ACM Conference on Economics and Computation","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114455418","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}

引用次数: 5

Incentive-Compatible Kidney Exchange in a Slightly Semi-Random Model 微半随机模型中的激励相容肾交换

Proceedings of the 22nd ACM Conference on Economics and Computation Pub Date : 2021-06-21 DOI: 10.1145/3465456.3467622

Avrim Blum, Paul Gölz

{"title":"Incentive-Compatible Kidney Exchange in a Slightly Semi-Random Model","authors":"Avrim Blum, Paul Gölz","doi":"10.1145/3465456.3467622","DOIUrl":"https://doi.org/10.1145/3465456.3467622","url":null,"abstract":"Motivated by kidney exchange, we study the following mechanism-design problem: On a directed graph (of transplant compatibilities among patient--donor pairs), the mechanism must select a simple path (a chain of transplantations) starting at a distinguished vertex (an altruistic donor) such that the total length of this path is as large as possible (a maximum number of patients receive a kidney). However, the mechanism does not have direct access to the graph. Instead, the vertices are partitioned over multiple players (hospitals), and each player reports a subset of her vertices to the mechanism. In particular, a player may strategically omit vertices to increase how many of her vertices lie on the path returned by the mechanism. Our objective is to find mechanisms that limit incentives for such manipulation while producing long paths. Unfortunately, in worst-case instances, competing with the overall longest path is impossible while incentivizing (approximate) truthfulness, i.e., requiring that hiding nodes cannot increase a player's utility by more than a factor of 1 + o(1). We therefore adopt a semi-random model where a small ($o(n)$) number of random edges are added to worst-case instances. While it remains impossible for truthful mechanisms to compete with the overall longest path, we give a truthful mechanism that competes with a weaker but non-trivial benchmark: the length of any path whose subpaths within each player have a minimum average length. In fact, our mechanism satisfies even a stronger notion of truthfulness, which we call matching-time incentive compatibility. This notion of truthfulness requires that each player not only reports her nodes truthfully but also does not stop the returned path at any of her nodes in order to divert it to a continuation inside her own subgraph.","PeriodicalId":395676,"journal":{"name":"Proceedings of the 22nd ACM Conference on Economics and Computation","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132093620","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}

引用次数: 7