An Agent-Based Simulation Approach to Comparative Analysis of Enforcement Mechanisms.

Incentive-based enforcement can be an effective mechanism for fostering cooperation in open distributed systems. The strength of such systems is the absence of a central controlling instance, but at the same time, they do depend upon (voluntary) regulation to achieve system goals, creating a potential "tragedy of the commons". Many different mechanisms have been proposed, both in the multi-agent systems and the social science communities, to solve the commons problem by using incentive-based enforcement. This paper advocates the use of agent-based simulation to carry out detailed comparative analysis of competing enforcement mechanisms, by providing common settings, the environment and the basis for comprehensive statistical analysis. To advance this argument, we take the case study of wireless mobile grids, a future generation mobile phone concept, to ground our experiments and analyse three different enforcement approaches: police entities, image information and a well-known existing reputation mechanism. The contribution of this paper is not the enforcement mechanisms themselves, but their comparison in a common setting through which we demonstrate by simulation and statistical analysis that enforcement can improve cooperation and that a relatively small percentage (of the population as a whole) of police agents outperforms (under the chosen metrics) image- and reputation-based approaches. Hence, qualified conclusions may be drawn for the application of such mechanisms generally in open distributed systems.