Incentive-Based Control of Asynchronous Best-Response Dynamics on Binary Decision Networks

Various populations of interacting decision-making agents can be modeled by asynchronous best-response dynamics, or equivalently, linear threshold dynamics. Building upon recent convergence results in the absence of control, we now consider how such a network can be efficiently driven to a desired equilibrium state by offering payoff incentives or rewards for using a particular strategy, either uniformly or targeted to individuals. We begin by showing that strategy changes are monotone following an increase in payoffs in coordination games, and that the resulting equilibrium is unique. Based on these results, for the case when a uniform incentive is offered to all agents, we show how to compute the optimal incentive using a binary search algorithm. When different incentives can be offered to each agent, we propose a new algorithm to select which agents should be targeted based on maximizing a ratio between the cascading effect of a strategy switch by each agent and the incentive required to cause the agent to switch. Simulations show that this algorithm computes near-optimal targeted incentives for a wide range of networks and payoff distributions in coordination games and can also be effective for anti-coordination games

Strategic Investment in Protection in Networked Systems

We study the incentives that agents have to invest in costly protection against cascading failures in networked systems. Applications include vaccination, computer security and airport security. Agents are connected through a network and can fail either intrinsically or as a result of the failure of a subset of their neighbors. We characterize the equilibrium based on an agent's failure probability and derive conditions under which equilibrium strategies are monotone in degree (i.e. in how connected an agent is on the network). We show that different kinds of applications (e.g. vaccination, malware, airport/EU security) lead to very different equilibrium patterns of investments in protection, with important welfare and risk implications. Our equilibrium concept is flexible enough to allow for comparative statics in terms of network properties and we show that it is also robust to the introduction of global externalities (e.g. price feedback, congestion).Comment: 32 pages, 3 figure

The minority game: An economics perspective

This paper gives a critical account of the minority game literature. The minority game is a simple congestion game: players need to choose between two options, and those who have selected the option chosen by the minority win. The learning model proposed in this literature seems to differ markedly from the learning models commonly used in economics. We relate the learning model from the minority game literature to standard game-theoretic learning models, and show that in fact it shares many features with these models. However, the predictions of the learning model differ considerably from the predictions of most other learning models. We discuss the main predictions of the learning model proposed in the minority game literature, and compare these to experimental findings on congestion games.Comment: 30 pages, 4 figure

A survey on the analysis and control of evolutionary matrix games

In support of the growing interest in how to efficiently influence complex systems of interacting self interested agents, we present this review of fundamental concepts, emerging research, and open problems related to the analysis and control of evolutionary matrix games, with particular emphasis on applications in social, economic, and biological networks. (C) 2018 Elsevier Ltd. All rights reserved

The Minority Game: An Economics Perspective

This paper gives a critical account of the minority game literature. The minority game is a simple congestion game: players need to choose between two options, and those who have selected the option chosen by the minority win. The learning model proposed in this literature seems to differ markedly from the learning models commonly used in economics. We relate the learning model from the minority game literature to standard game-theoretic learning models, and show that in fact it shares many features with these models. However, the predictions of the learning model differ considerably from the predictions of most other learning models. We discuss the main predictions of the learning model proposed in the minority game literature, and compare these to experimental findings on congestion games.Learning;congestion games;experiments.

Social Reinforcement: Cascades, Entrapment and Tipping

There are many social situations in which the actions of different agents reinforce each other. These include network effects and the threshold models used by sociologists (Granovetter, Watts) as well as Leibenstein's "bandwagon effects." We model such situations as a game with increasing differences, and show that tipping of equilibria as discussed by Schelling, cascading and Dixit's results on clubs with entrapment are natural consequences of this mutual reinforcement. If there are several equilibria, one of which Pareto dominates, then we show that the inefficient equilibria can be tipped to the efficient one, a result of interest in the context of coordination problems.

The impact of information provision on agglomeration bonus performance : an experimental study on local networks

This research was funded by the European Investment Bank (EIB) under the EIB-University Research Action ProgrammeThe agglomeration bonus is an incentive mechanism to induce adjacent landowners to spatially coordinate their land use for the delivery of ecosystem services from farmland. This paper uses laboratory experiments to explore the performance of the agglomeration bonus in achieving the socially optimal land management configuration in a local network environment where the information available to subjects varies and the strategic setting is unfavorable for efficient coordination. The experiments indicate that if subjects are informed about both their direct and indirect neighbors' actions, they are more likely to produce the socially optimal configuration. Thus effectiveness of the policy can be improved by implementing information dissemination exercises among landowners. However given the adverse strategic setting, increased game experience leads to coordination failure and optimal land choices only at the localized level independent of the information available to subjects. Thus success of the agglomeration bonus scheme on real landscapes will have to take account of the roles of both information and experience on participant behavior.PostprintPeer reviewe

Equilibria in a Dynamic Global Game: The Role of Cohort Effects

We introduce strategic waiting in a global game setting with irreversible investment. Players can wait in order to make a better informed decision. We allow for cohort effects and discuss when they arise endogenously in technology adoption problems with positive contemporaneous network effects. Formally, cohort effects lead to intra-period network effects being greater than inter-period network effects. Depending on the nature of the cohort effects, the dynamic game may or may not satisfy dynamic strategic complementarity. If it does, our model has a unique rationalizable outcome. Otherwise, there exists parameter values for which multiple equilibria arise because player have a strong incentive to invest at the same point in time others do. ZUSAMMENFASSUNG - (Gleichgewichte in einem Dynamischen Globalen Spiel: Die Rolle von Kohorteneffekten) Koordinationsspiele haben typischerweise multiple Nashgleichgewichte mit sich selbsterfüllenden Erwartungen. Die Theorie der globalen Spiele führt Unsicherheit und private Informationen in statischen Koordinationsspielen ein und zeigt die Bedingungen auf, unter denen dies zu einem eindeutigen Gleichgewicht führt. In diesem Beitrag untersuchen wir ein Zweiperiodenspiel, in welchem die Spieler eine irreversible Investitionsentscheidung mit einer positiven Netwerkexternalität treffen. In der ersten Periode wählen die Spieler, ob sie sofort investieren oder auf bessere Informationen über das Projekt warten. Wir zeigen, dass Kohorteneffekte bei Technologiewahlproblemen mit positiven Netzwerkexternalitäten auftreten und untersuchen ihre Auswirkungen. Kohorteneffekte führen dazu, dass die Intraperioden-Netzwerkeffekte größer sind als die Interperioden-Netzwerkeffekte. Aus technischer Sicht bestimmen die Kohorteneffekte, ob das globale Spiel die Eigenschaft der dynamischen strategischen Komplemantarität erfüllt. Diese Eigenschaft wiederum impliziert, dass unser Modell eine eindeutige rationalisierbare Lösung hat. Ist diese Eigenschaft nicht erfüllt, so hat jeder Spieler einen hohen Anreiz zum gleichen Zeitpunkt wie die andern Spieler zu investieren. In diesem Fall exstieren Parameterwerte für welche unser Spiel multiple Nashgleichgewichtslösungen hat.Global Game, Strategic Waiting, Coordination, Strategic Complementarities, Period-specific Network Effects, Equilibrium Selection