手法を比較

	Expected Utility Model of War	Bargaining Model of War
分野	International Relations	International Relations
系統	MCDM	MCDM
提唱年	1981	1995
提唱者	Bruce Bueno de Mesquita	James D. Fearon
種類	Formal rational-choice model of conflict initiation	Formal model of war as bargaining failure
原典	Bueno de Mesquita, B. (1981). The War Trap. New Haven, CT: Yale University Press.	Fearon, J. D. (1995). Rationalist explanations for war. International Organization, 49(3), 379–414.
別名	Expected Utility Theory of War, The War Trap Model, Rational Choice Model of War Initiation, Expected-Utility Conflict Model	Rationalist Explanations for War, Bargaining Theory of War, Crisis Bargaining Model, Fearon Bargaining Model
関連	3	3
概要	The expected utility model of war, introduced by Bruce Bueno de Mesquita in The War Trap (1981), treats the decision to initiate international conflict as a rational gamble. A leader is modeled as comparing the utility of the outcome they could win against the utility of the outcome they could lose, each weighted by the probability of winning or losing, and is predicted to challenge another state only when this expected utility is positive. It was among the first attempts to derive testable predictions about war initiation from explicit assumptions of rational, utility-maximizing decision making.	The bargaining model of war, given its canonical statement by James Fearon in 'Rationalist Explanations for War' (1995), treats war not as the failure of reason but as a failure of bargaining. Because fighting is costly and uncertain, there almost always exists a peaceful division of the disputed stakes that both rational states would prefer to the gamble of war. The puzzle, and the model's central contribution, is to identify the specific conditions — private information with incentives to misrepresent, commitment problems, and issue indivisibility — under which rational, unitary states nonetheless fail to reach such a settlement.