We show that, when restricted to positive games, games whose Harsanyi dividends are non-negative, additivity together with efficiency, individual rationality and the null player property, characterizes the core as a maximal set-valued solution.
Dehez, P. (2024). Axiomatization of the core of positive games. Economic Theory Bulletin. Accepted/in-press. https://doi.org/10.1007/s40505-024-00276-8 (Original work published 2024)