646 International Organization Sender Do nothing Threaten sanctions Target Status quo ante Back down Stand firm Sender Target acquiescence Back down Stand firm Sender Sanctions acquiescence imposition FIGURE 1.A model of economic coercion conditions of full information,perfectly divisible demands,and rational utility maxi- mizers,there are only two equilibrium outcomes.Either the sender will decline to threaten coercion,or the target will acquiesce to the sender's threat of coercion. Under these conditions,the threat of sanctions should have a 100 percent success rate,and sanctions should never be imposed. Obviously,this does not mirror what one observes in international relations. The theoretical response has been to tweak the assumptions underlying this basic bargaining model.The use of force and the use of sanctions have similar dynam- ics,so is not surprising that game-theoretic models of economic sanctions echo James Fearon's menu of explanations for why rational,unitary actors go to war rather than come to an incentive-compatible bargain before the outbreak of hostil- ities.5 Fearon offers three possible explanations:(1)private information about an actor's resolve combined with an incentive to misrepresent such information, (2)an inability for one or both states to credibly commit to mutually preferable bargains,and (3)a disputed issue that is inherently indivisible.The models de- scribed below differ on which combination of these explanations is responsible 15.Fearon 1995.646 International Organization Sender Sender Sanctions acquiescence imposition FIGURE 1. A model of economic coercion conditions of full information, perfectly divisible demands, and rational utility maxi￾mizers, there are only two equilibrium outcomes. Either the sender will decline to threaten coercion, or the target will acquiesce to the sender's threat of coercion. Under these conditions, the threat of sanctions should have a 100 percent success rate, and sanctions should never be imposed. Obviously, this does not mirror what one observes in international relations. The theoretical response has been to tweak the assumptions underlying this basic bargaining model. The use of force and the use of sanctions have similar dynam￾ics, so is not surprising that game-theoretic models of economic sanctions echo James Fearon's menu of explanations for why rational, unitary actors go to war rather than come to an incentive-compatible bargain before the outbreak of hostil￾ities.15 Fearon offers three possible explanations: (I) private information about an actor's resolve combined with an incentive to misrepresent such information, (2) an inability for one or both states to credibly commit to mutually preferable bargains, and (3) a disputed issue that is inherently indivisible. The models de￾scribed below differ on which combination of these explanations is responsible 15. Fearon 1995