Outcome (game theory)

Philosophy

Contrast (vision)

Telecommunications

Core (optical fiber)

Computer science

Emptiness

Fraction (chemistry)

Organic chemistry

Mathematics

Value (mathematics)

Epistemology

Artificial intelligence

Cluster analysis

Mathematical economics

Chemistry

Class (philosophy)

Machine learning

ACM Transactions on Economics and Computation

The work we present in this article initiated the formal study of fractional hedonic games (FHGs), coalition formation games in which the utility of a player is the average value he ascribes to the members of his coalition. Among other settings, this covers situations in which players only distinguish between friends and non-friends and desire to be in a coalition in which the fraction of friends is maximal. FHGs thus not only constitute a natural class of succinctly representable coalition formation games but also provide an interesting framework for network clustering. We propose a number of conditions under which the core of FHGs is non-empty and provide algorithms for computing a core stable outcome. By contrast, we show that the core may be empty in other cases, and that it is computationally hard in general to decide non-emptiness of the core.

Fractional Hedonic Games