Consistency and the core in games with externalities

In the presence of externalities across coalitions, Dutta et al. (J Econ Theory 145:2380–2411, 2010) characterize their value by extending Hart and Mas-Colell reduced game consistency. In the present paper, we provide a characterization result for the core for games with externalities by extending one form of consistency studied by Moulin (J Econ Theory 36:120–148, 1985), which is often referred to as the complement-reduced game property. Moreover, we analyze another consistency formulated by Davis and Maschler (Naval Res Logist Quart 12:223–259, 1965), called the max-reduced game property and a final consistency called the projection-reduced game property. In environments with externalities, we discuss some asymmetric results among these different forms of reduced games.