The world we live in is expanding its borders by letting the virtual become part of our lives. Digitisation equally pervades the public and the private sectors and transforms interactions between individuals, and between individuals and the state. For instance, the UK government is now in the process of digitising a whole range of processes and interactions with its citizens, through the Governmental Digital Service (GDS). In this article we aim to prove that virtual worlds provide a playground for social (...) engineers, legal researchers and philosophers, for two reasons. First, virtual worlds offer confirmations of social theories of cooperation, they illustrate that cooperation among individuals emerges spontaneously where there are no established forms of governance and decision. Secondly, virtual worlds offer sandboxes where the peculiarities of online interaction can be observed. (shrink)

The traditional solution concept for noncooperative game theory is the Nash equilibrium, which contains an implicit assumption that players’ probability distributions satisfy t probabilistic independence. However, in games with more than two players, relaxing this assumption results in a more general equilibrium concept based on joint beliefs. This article explores the implications of this joint-beliefs equilibrium concept for two kinds of conflictual coordination games: crisis bargaining and public goods provision. We find that, using updating consistent with Bayes’ rule, players’ beliefs (...) converge to equilibria in joint beliefs which do not satisfy probabilistic independence. In addition, joint beliefs greatly expand the set of mixed equilibria. On the face of it, allowing for joint beliefs might be expected to increase the prospects for coordination. However, we show that if players use joint beliefs, which may be more likely as the number of players increases, then the prospects for coordination in these games declines vis-à-vis independent beliefs. (shrink)