Game theoretic approach to multiparty coalition

The seminal work, for the study of game theoretic approach to multiparty coalition formation is Ricker's (1962) titled the theory of political coalitions, where he has argued that a multiparty system will converge to a two party or two coalitions of almost equal size. A key concept here is the "minimum winning coalition", the members of a coalition tend to keep the number of participants as small as possible i.e., minimum necessary to win, that the shares of his office benefits remains few.