On Linear Congestion Games with Altruistic Social Context

We study the issues of existence and inefficiency of pure Nash equilibria in linear congestion games with altruistic social context, in the spirit of the model recently proposed by de Keijzer {\em et al.} \cite{DSAB13}. In such a framework, given a real matrix $\Gamma=(\gamma_{ij})$ specifying a particular social context, each player $i$ aims at optimizing a linear combination of the payoffs of all the players in the game, where, for each player $j$, the multiplicative coefficient is given by the value $\gamma_{ij}$. We give a broad characterization of the social contexts for which pure Nash equilibria are always guaranteed to exist and provide tight or almost tight bounds on their prices of anarchy and stability. In some of the considered cases, our achievements either improve or extend results previously known in the literature

Price of Competition and Dueling Games

We study competition in a general framework introduced by Immorlica et al. and answer their main open question. Immorlica et al. considered classic optimization problems in terms of competition and introduced a general class of games called dueling games. They model this competition as a zero-sum game, where two players are competing for a user's satisfaction. In their main and most natural game, the ranking duel, a user requests a webpage by submitting a query and players output an ordering over all possible webpages based on the submitted query. The user tends to choose the ordering which displays her requested webpage in a higher rank. The goal of both players is to maximize the probability that her ordering beats that of her opponent and gets the user's attention. Immorlica et al. show this game directs both players to provide suboptimal search results. However, they leave the following as their main open question: "does competition between algorithms improve or degrade expected performance?" In this paper, we resolve this question for the ranking duel and a more general class of dueling games. More precisely, we study the quality of orderings in a competition between two players. This game is a zero-sum game, and thus any Nash equilibrium of the game can be described by minimax strategies. Let the value of the user for an ordering be a function of the position of her requested item in the corresponding ordering, and the social welfare for an ordering be the expected value of the corresponding ordering for the user. We propose the price of competition which is the ratio of the social welfare for the worst minimax strategy to the social welfare obtained by a social planner. We use this criterion for analyzing the quality of orderings in the ranking duel. We prove the quality of minimax results is surprisingly close to that of the optimum solution

After Images: Using Augusto Boal\u27s Image Theatre to Balance Artistry, Analysis, and Activism in the Performance Composition Process

In this study, I describe several performance experiments in which I applied Brazilian theatre artist Augusto Boal’s Image Theatre method to mobilize a composition process that is artistically exciting, politically relevant, and pedagogically engaging. Over the span of about seven years I used Image Theatre as the bedrock of my artistic practice as a director of social justice themed works for the stage. I show how using Image Theatre as a tool for performance composition can balance artistry (theatrical practice), analysis (cultural studies), and activism (collaborative struggles toward justice). To do so, I review relevant literature on Boal and Image Theatre to show how my research contributes to the ongoing conversation about the ethics and applications of Boal’s method, then describe three major performance projects in which I used Image Theatre as a method for staging collaborative performances addressing social justice topics. In each case study, I offer descriptions of the performance composition process and final performance product in order to reflect on several practical strategies for directors and teachers interested in creating collaborative performances that call for social change

Prospects of Cooperation in the Eastern Nile Basin : The case of Experimental Game Application

Tensions over the use of Nile waters have recently increased and no comprehensive agreement till date acceptable to all Eastern Nile Basin riparian countries exists. After years of escalating tensions between upstream and downstream countries of the Nile basin, mainly because of Ethiopia's construction of Grand Ethiopian Renaissance Dam (GERD), a sense of mistrust hangs over the dam's ultimate use. Preventing transboundary water conflicts cannot be realized without forming adequate cooperation in managing shared waters which through robust and equitable structures and institutions. Since conflict resolution is a political process to make decisions after a lengthy procedure of negotiations, cooperation at transboundary level needs much time, patience and persistence to have ampler chances to succeed if the drivers and interests of the riparian states are identified, quantified and shared with the help of diplomatic mechanisms. The nature of cooperative decision-making at the transboundary water scale is regarded as a complex system composed which cannot be forgone without diplomacy among parties to facilitate understanding of actors' interests by creating a transparent and confident environment. This study developed a series of laboratory game experiment as an approach to examine the impact of a set of incentivized compensation options to promote cooperation through trust building, reduction of decision makers' uncertainties and simplification of complexities. To test whether individuals have the ability to signal the economic gains expansion as a motive for cooperation, this study reports a laboratory game experiment in the form of non-binding, 3-player, trust games. Payoff schemes are calculated and provided using real-world data for the case of the Eastern Nile Basin under four different allocation scenarios. The analysis of exploring cooperation probability under each scenario aims to identify the likelihood of the "win for all" decisions, which could not be reached with the unilateral behavior of states, but through a stable integrative and collaborative framework. The results of the experimental games indicate that cooperation is indeed hard to establish in a strategic environment with a sense of uncertainty for the future, but it is still attainable. Since cooperation is mostly conditional, as long as a set of preconditions are available and certain ranges of incentives are ensured, cooperation continues. The result of the study demonstrates that basin-wide security requires regional cooperation while cooperative decision-making takes place in a transparent environment with a variety of compensation options, institutional reforms, and incentive-compatible considerations. In the end, key conclusions prove that sustained and open communication and information sharing can lead to collective actions. In order to establish joint decision-making for cooperation over the shared waters, recognition of all sorts of benefits cooperation brings in a short and long run, and fair distribution of those benefits among the riparian countries play a crucial role.Die durch die Verwendung von Nil-Gewässern ausgelösten Spannung erhöhen sich seit geraumer Zeit und nach wie vor wurde noch keine umfassende Vereinbarung getroffen, welche akzeptable Lösungsansätze für alle Staaten am östlichen Nilufer darstellt. Nach Jahren der immer wieder eskalierenden Spannungen zwischen Downstream- und Upstream-Länder im Nilbecken, insbesondere im Hinblick auf Äthiopiens Bau des Grand Äthiopien Renaissance Dam (GERD), schwebt ein Gefühl von Misstrauen über dem Damm und Nutzung. Da die Konfliktlösung einen politischen Prozess darstellt, mit Entscheidungen die nach langwierigen Verhandlungsverfahren getroffen werden, braucht die Zusammenarbeit auf grenzüberschreitender Ebene, viel Zeit, Geduld und Beharrlichkeit, sofern Entscheidungsgrundlagen und Interessen der Uferstaaten mittels diplomatischer Mechanismen bekannt und quantifiziert wurden, um letztlich eine höhere Chance auf Erfolg zu realisieren/erhalten/haben/in Aussicht zu haben. Das Wesen der kooperativen Entscheidungsfindung in einem grenzüberschreitenden Wassersystem wird als ein komplexes Netzwerksystem betrachtet, welches nicht auf Diplomatie unter/zwischen den Parteien verzichten kann, um folglich das Verständnis von Interessen, durch Schaffung eines transparenten und zuversichtlichen Umfeldes, zu erleichtern. Diese Studie trägt dazu bei, eine Reihe von Laborspiel- Experimenten zu entwickeln, welche eine Reihe von Anreizkompensationsoptionen untersuchen, die die Kooperation durch Vertrauensbildung, also der Minderung der Zweifel Entscheidungsträger und die Vereinfachung der Komplexität fördern. Um zu testen, ob Einzelpersonen fähig sind, ihre Bereitschaft zur Zusammenarbeit zu signalisieren, wodurch sie ihre ökonomischen Gewinne erhöhen könnten, zeigt die Studie eine Reihe von experimentellen Laboratorien in Form von unverbindlichen, 3-Spieler, Vertrauensspielen. Die Analyse der Kooperationswahrscheinlichkeitserforschung jedes Szenarios zielt darauf ab, die Wahrscheinlichkeit der "win for all" -Situation zu identifizieren, die zwar nicht mit dem einseitigen Verhalten der Staaten erreichbar ist, jedoch durch einen stabilen, integrativen und kooperativen Rahmen bewerkstelligt werden kann. Die Ergebnisse des experimentellen Spiels zeigten, dass obwohl Zusammenarbeit in strategischen Umfeldern mit ungewisser Zukunft schwierig zu implementieren ist, dennoch, sofern Vorbedingungen zur Verfügung stehen, machbar ist. Da die Kooperation meist unter Vorbehalt ist, schreitet die Zusammenarbeit nur voran, solange eine Reihe von Voraussetzungen gegeben ist und bestimmte Anreizbereiche sichergestellt sind. Das Ergebnis der Studie zeigt, dass ein Becken weite Effizienz, eine regionale Kooperation erfordert und eine kooperative Entscheidungsfindung in einem transparenten Umfeld unter einer Vielzahl von Ausgleichsoptionen, institutionellen Veränderungen und anreizkompatiblen Überlegungen, möglich ist. Die Schlussfolgerungen sind letztlich, dass eine nachhaltige und offene Kommunikation zur Zusammenarbeit führen und eine kooperative Entscheidungsfindung schaffen kann. Das Verständnis für den wirtschaftlichen Nutzen durch die Zusammenarbeit, die Kooperationsbereitschaft und die Vertrauenswürdigkeit der Entscheidungsträger stellen die zentralen Problemfelder dar