25 citations · 124 across the 24 of their papers we have counts for
29 papers
Reward Schemes and Committee Sizes in Proof of Stake Governance
Georgios Birmpas, Philip Lazos, Evangelos Markakis +1
In this paper, we investigate the impact of reward schemes and committee sizes motivated by governance systems over blockchain communities. We introduce a model for elections with…
Single-token vs Two-token Blockchain Tokenomics
Aggelos Kiayias, Philip Lazos, Paolo Penna
We study long-term equilibria that arise in the token monetary policy, or tokenomics, design of proof-of-stake (PoS) blockchain systems that engage utility maximizing users and val…
Algorithmically Fair Maximization of Multiple Submodular Objective Functions and Implications to Constrained Fair Division
Georgios Amanatidis, Georgios Birmpas, Philip Lazos +2
Constrained maximization of submodular functions is a central problem in combinatorial optimization. In many realistic scenarios, multiple agents each need to maximize their own su…
On the Potential and Limitations of Proxy Voting: Delegation with Incomplete Votes
Georgios Amanatidis, Aris Filos-Ratsikas, Philip Lazos +2
We study elections where voters are faced with the challenge of expressing preferences over an extreme number of issues under consideration. This is largely motivated by emerging b…
Would Friedman Burn your Tokens?
Aggelos Kiayias, Philip Lazos, Jan Christoph Schlegel
Cryptocurrencies come with a variety of tokenomic policies as well as aspirations of desirable monetary characteristics that have been described by proponents as 'sound money' or e…
Optimal Testing and Containment Strategies for Universities in Mexico amid COVID-19
Luis Benavides-Vázquez, Héctor Alonso Guzmán-Gutiérrez, Jakob Jonnerby +5
This work sets out a testing and containment framework developed for reopening universities in Mexico following the lockdown due to COVID-19. We treat diagnostic testing as a resou…
Tiered Mechanisms for Blockchain Transaction Fees
Aggelos Kiayias, Elias Koutsoupias, Philip Lazos +1
Blockchain systems come with the promise of being inclusive for a variety of decentralized applications (DApps) that can serve different purposes and have different urgency require…
Round-Robin Beyond Additive Agents: Existence and Fairness of Approximate Equilibria
Georgios Amanatidis, Georgios Birmpas, Philip Lazos +2
Fair allocation of indivisible goods has attracted extensive attention over the last two decades, yielding numerous elegant algorithmic results and producing challenging open quest…
Decentralised Update Selection with Semi-Strategic Experts
Georgios Amanatidis, Georgios Birmpas, Philip Lazos +1
Motivated by governance models adopted in blockchain applications, we study the problem of selecting appropriate system updates in a decentralised way. Contrary to most existing vo…
Parallel Contests for Crowdsourcing Reviews: Existence and Quality of Equilibria
Georgios Birmpas, Lyudmila Kovalchuk, Philip Lazos +1
Motivated by the intricacies of allocating treasury funds in blockchain settings, we study the problem of crowdsourcing reviews for many different proposals, in parallel. During th…
SoK: Blockchain Governance
Aggelos Kiayias, Philip Lazos
Blockchain systems come with a promise of decentralization that often stumbles on a roadblock when key decisions about modifying the software codebase need to be made. This is atte…
Single-Sample Prophet Inequalities via Greedy-Ordered Selection
Constantine Caramanis, Paul Dütting, Matthew Faw +6
We study single-sample prophet inequalities (SSPIs), i.e., prophet inequalities where only a single sample from each prior distribution is available. Besides a direct, and optimal,…
Allocating Indivisible Goods to Strategic Agents: Pure Nash Equilibria and Fairness
Georgios Amanatidis, Georgios Birmpas, Federico Fusco +3
We consider the problem of fairly allocating a set of indivisible goods to a set of strategic agents with additive valuation functions. We assume no monetary transfers and, therefo…
Prophet Inequalities for Matching with a Single Sample
Paul Dütting, Federico Fusco, Philip Lazos +2
We consider the prophet inequality problem for (not necessarily bipartite) matching problems with independent edge values, under both edge arrivals and vertex arrivals. We show con…
On the Complexity of Equilibrium Computation in First-Price Auctions
Aris Filos-Ratsikas, Yiannis Giannakopoulos, Alexandros Hollender +2
We consider the problem of computing a (pure) Bayes-Nash equilibrium in the first-price auction with continuous value distributions and discrete bidding space. We prove that when b…
RPPLNS: Pay-per-last-N-shares with a Randomised Twist
Philip Lazos, Francisco J. Marmolejo-Cossío, Xinyu Zhou +1
"Pay-per-last--shares" (PPLNS) is one of the most common payout strategies used by mining pools in Proof-of-Work (PoW) cryptocurrencies. As with any payment scheme, it is impera…
Submodular Maximization subject to a Knapsack Constraint: Combinatorial Algorithms with Near-optimal Adaptive Complexity
Georgios Amanatidis, Federico Fusco, Philip Lazos +3
Submodular maximization is a classic algorithmic problem with multiple applications in data mining and machine learning; there, the growing need to deal with massive instances moti…
Fast Adaptive Non-Monotone Submodular Maximization Subject to a Knapsack Constraint
Georgios Amanatidis, Federico Fusco, Philip Lazos +2
Constrained submodular maximization problems encompass a wide variety of applications, including personalized recommendation, team formation, and revenue maximization via viral mar…
Maximising the Benefits of an Acutely Limited Number of COVID-19 Tests
Jakob Jonnerby, Philip Lazos, Edwin Lock +4
We propose a novel testing and containment strategy in order to contain the spread of SARS-CoV2 while permitting large parts of the population to resume social and economic activit…
Efficient Two-Sided Markets with Limited Information
Paul Dütting, Federico Fusco, Philip Lazos +2
A celebrated impossibility result by Myerson and Satterthwaite (1983) shows that any truthful mechanism for two-sided markets that maximizes social welfare must run a deficit, resu…
Pandora's Box Problem with Order Constraints
Shant Boodaghians, Federico Fusco, Philip Lazos +1
The Pandora's Box Problem, originally formalized by Weitzman in 1979, models selection from set of random, alternative options, when evaluation is costly. This includes, for exampl…
Fairness and Efficiency in DAG-based Cryptocurrencies
Georgios Birmpas, Elias Koutsoupias, Philip Lazos +1
Bitcoin is a decentralised digital currency that serves as an alternative to existing transaction systems based on an external central authority for security. Although Bitcoin has…
Reallocating Multiple Facilities on the Line
Dimitris Fotakis, Loukas Kavouras, Panagiotis Kostopanagiotis +3
We study the multistage -facility reallocation problem on the real line, where we maintain facility locations over stages, based on the stage-dependent locations of …
Blockchain Mining Games with Pay Forward
Elias Koutsoupias, Philip Lazos, Paolo Serafino +1
We study the strategic implications that arise from adding one extra option to the miners participating in the bitcoin protocol. We propose that when adding a block, miners also ha…