Fair Distribution of Collective Obligations

In social mechanism design, obligation distribution creates individual or contractual obligations that imply a collective obligation. A distinguishing feature from group planning is that also the sanction of the collective obligation has to be distributed, for example by creating sanctions for the individual or contractual obligations. In this paper we address fairness in obligation distribution for more or less powerful agents, in the sense that some agents can perform more or less actions than others. Based on this power to perform actions, we characterize a trade-off in negotiation power. On the one hand, more powerful agents may have a disadvantage during the negotiation, as they may be one of the few or even the only agent who can see to some of the actions that have to be performed to fulfill the collective obligation. On the other hand, powerful agents may have an advantage in some negotiation protocols, as they have a larger variety of proposals to choose from. Moreover, powerful agents have an advantage because they can choose from a larger set of possible coalitions. We present an ontology and measures to find a fair tradeoff between these two forces in social mechanism design.