Opinion diffusion is studied on social graphs where agents hold binary opinions and pressure leads them to conform the opinion manifested by their neighbors. Within this setting, questions related whether a minority/majority can spread it supports all other are considered.It shown that, no matter of graph given at hand, there always exists group formed half that annihilate opposite opinion. Instead, influence power minorities depends certain features underlying graphs, which NP-hard be...

We focus on the scenario in which messages pro and/or against one or multiple candidates are spread through a social network order to affect votes of receivers. Several results known literature when manipulator can make seeding by buying influencers. In this paper, instead, we assume set influencers and their be given, ask whether (e.g., platform) alter outcome election adding removing edges network. study wide range cases distinguishing for number kind over provide positive result, showing...

Logit Dynamics [Blume, Games and Economic Behavior, 1993] is a randomized best response dynamics for strategic games: at every time step player selected uniformly random she chooses new strategy according to probability distribution biased toward strategies promising higher payoffs. This process defines an ergodic Markov chain, over the set of profiles game, whose unique stationary long-term equilibrium concept game. However, when mixing chain large (e.g., exponential in number players),...

Online social networks are nowadays one of the most effective and widespread tools used to share information. In addition being employed by individuals for communicating with friends acquaintances, brands marketing customer service purposes, they constitute a primary source daily news significant number users. Unfortunately, besides legit news, also allow effectively spread inaccurate or even entirely fabricated ones. Also due sensationalist claims, misinformation can from original sources...

We present the first general bounds on mixing time of logit dynamics for wide classes strategic games. The describes behaviour a complex system whose individual components act "selfishly" and keep responding according to some partial ("noisy") knowledge system. In particular, we prove nearly tight potential games with dominant strategies. Our results show that, games, is upper lower bounded by an "exponential" in inverse noise maximum difference. Instead, strategies, cannot grow arbitrarily...

The emergence of online social networks has revolutionized the way people seek and share information. Nowadays, popular sites as Twitter, Facebook Google+ are among major news sources well most effective channels for viral marketing. However, these also became channel spreading misinformation, accidentally or maliciously. widespread diffusion inaccurate information fake can lead to undesirable severe consequences, such panic, libelous campaigns conspiracies. In order guarantee...

In a discrete preference game, each agent is equipped with an internal belief and declares her from set of alternatives. The payoff depends on whether the declared agrees coordination preferences by neighbors in underlying social network. These games have been used to model formation opinions adoption innovations networks.Recently, researchers obtained bounds Price Anarchy Stability they studied which extent winning reached via best-response dynamics disagrees majority beliefs. this work, we...

Motivated by privacy and security concerns in online social networks, we study the role of pressure opinion games. These are games, important economics sociology, that model formation opinions a network. We enrich definition (noisy) best-response dynamics for games introducing pressure, increasing with time, to reach an agreement.We prove clique always converges consensus (no matter level noise) if is high enough. Moreover, provide (tight) bounds on speed convergence; these polynomial number...

Friedkin and Johnsen (1990) modeled opinion formation in social networks as a dynamic process which evolves rounds: at each round agent updates her expressed to weighted average of innate belief the opinions previous by neighbors. The stubbornness level an represents tendency express close belief.
 Motivated observation that beliefs, levels even relations can co-evolve together with opinions, we present new model where dynamics runs co-evolving environment. We assume agents’ vary...

Previous chapter Next Full AccessProceedings Proceedings of the 2012 Annual ACM-SIAM Symposium on Discrete Algorithms (SODA)Metastability Logit Dynamics for Coordination GamesVincenzo Auletta, Diodato Ferraioli, Francesco Pasquale, and Giuseppe PersianoVincenzo Persianopp.1006 - 1024Chapter DOI:https://doi.org/10.1137/1.9781611973099.80PDFBibTexSections ToolsAdd to favoritesExport CitationTrack CitationsEmail SectionsAboutAbstract [Blume, Games Economic Behavior, 1993] is a randomized best...

We aim at identifying a minimal set of conditions under which algorithms with good approximation guarantees are truthful without money. In line recent literature, we wish to express such via verification assumptions, i.e., kind agents' misbehavior that can be made impossible by the designer.We initiate this research endeavour for paradigmatic problem in approximate mechanism design money, facility location. It is known how truthfulness imposes (even severe) losses and certain notions...

Opinion diffusion has been largely studied in the literature on settings where opinion whose spread to be maximized, say white, competes against one only, black. For instance, for mechanisms modeled terms of best response dynamics over majority agents (who change their as conform it neighbors), is known that can maximized via certain greedy computed polynomial time. This setting precisely considered paper. However, differently from earlier literature, assumed further opinion, gray, available...

Obviously strategyproof (OSP) mechanisms maintain the incentive compatibility of agents that are not fully rational. They have been object a number studies since their recent definition. A research agenda, initiated in [Ferraioli and Ventre, 2017], is to find small set (possibly, smallest) conditions allowing implement an OSP mechanism. To this aim, we define model probabilistic verification wherein caught misbehaving with certain probability, show how can every social choice function at...

Obvious strategyproofness (OSP) is an appealing concept as it allows to maintain incentive compatibility even in the presence of agents that are not fully rational, e.g., those who struggle with contingent reasoning (Li 2015). However, has been shown impose some limitations, no OSP mechanism can return a stable matching (Ashlagi and Gonczarowski We here deepen study limitations mechanisms by looking at their approximation guarantees for basic optimization problems paradigmatic area, i.e.,...