coalitional

Coalitional is an adjective relating to a coalition, an alliance of individuals or organizations formed to achieve a common objective. The term is used across political science, sociology, and game theory to describe relationships and arrangements among cooperating parties.

In politics, coalitional politics describes situations where no single party holds an outright majority, prompting two or more parties to form a governing coalition. Coalition agreements typically specify policy priorities, ministerial portfolios, and conditions for sustaining the coalition. The stability of such governments depends on policy alignment, the tolerance of coalition partners for concessions, and external events; coalitions can be ideologically broad or narrow and may be fragile when internal disagreements arise.

In game theory and economics, coalitional games study how groups of players can cooperate and share the payoff. A coalition forms when its members expect to gain more together than apart. Core concepts include the value of a coalition, the distribution of payoffs among members, and stability of the outcome, such as the core or the Shapley value. Coalition formation can be voluntary or induced by rules, contracts, or external incentives.

Coalitional behavior also appears in sociology and international relations, where actors temporarily align to achieve goals, such as negotiating blocs, security alliances, or issue-based partnerships. Coalitional analysis helps explain bargaining power, dilution of influence, and the dynamics of alliance formation.

Etymology: from Latin coalitio, meaning a uniting or joining.