Distributed Computing with Adaptive Heuristics

We use ideas from distributed computing to study dynamic environments in which computational nodes, or decision makers, follow adaptive heuristics (Hart 2005), i.e., simple and unsophisticated rules of behavior, e.g., repeatedly "best replying" to others' actions, and minimizing "regret", that have been extensively studied in game theory and economics. We explore when convergence of such simple dynamics to an equilibrium is guaranteed in asynchronous computational environments, where nodes can act at any time. Our research agenda, distributed computing with adaptive heuristics, lies on the borderline of computer science (including distributed computing and learning) and game theory (including game dynamics and adaptive heuristics). We exhibit a general non-termination result for a broad class of heuristics with bounded recall---that is, simple rules of behavior that depend only on recent history of interaction between nodes. We consider implications of our result across a wide variety of interesting and timely applications: game theory, circuit design, social networks, routing and congestion control. We also study the computational and communication complexity of asynchronous dynamics and present some basic observations regarding the effects of asynchrony on no-regret dynamics. We believe that our work opens a new avenue for research in both distributed computing and game theory.Comment: 36 pages, four figures. Expands both technical results and discussion of v1. Revised version will appear in the proceedings of Innovations in Computer Science 201

Social learning with local interactions

We study a simple dynamic model of social learning with local informational exter-nalities. There is a large population of agents, who repeatedly have to choose one, out of two, reversible actions, each of which is optimal in one, out of two, unknown states of the world. Each agent chooses rationally, on the basis of private information (s)he receives by a symmetric binary signal on the state, as well as the observation of the action chosen among their nearest neighbours. Actions can be updated at revision opportunities that agents receive in a random sequential order. Strategies are stationary, in that they do not depend on time, nor on location. We show that: if agents receive equally informative signals, and observe both neighbours, then the social learning process is not adequate and the process of actions converges ex-ponentially fast to a con�guration where some agents are permanently wrong; if agents are unequally informed, in that their signal is either fully informative or fully uninformative (both with positive probability), and observe one neighbour, then the social learning process is adequate and everybody will eventually choose the action that is correct given the state. Convergence, however, obtains very slowly, namely at rate pt: We relate the�findings with the literature on social learning and discuss the property of effciency of the information transmission mechanism under local interaction. <br><br> Keywords; social learning, bayesian learning, local informational external-ities, path dependence, consensus, clustering, convergence Rates

Art, public authorship and the possibility of re-democratization

The subject of this study is a large public art project by German artist Jochen Gerz, which was part of the urban regeneration program The Phoenix Initiative in Coventry City, 1999-2004. The study presents a short historical backdrop to Gerz’s work by way of defining ‘public authorship’ of which the Coventry project is one example. It extends the literature on contemporary countermonument by assessing Gerz’s artistic strategy in using a monument to exploring the conditions of public culture and possible shape of a cultural public sphere in the contemporary city. The public art project lasted over five years and was a mechanism by which the political issues at stake in the public life of Coventry, particularly the socio-historic conflicts that are constitutive of its civic identity, were articulated. The study argues that public authorship succeeded in identifying some crucial coordinates in the political constitution of public culture in Coventry, but in the face of competing civic rhetoric and new urban policy initiatives, the project remains an open inquiry. This study concludes by identifying some critical lines of inquiry for future studies in art’s critical role in the public sphere