The Customary International Law Supergame February 23, 200 Number of actors refers to the actors that are potentially relevant to joint welfare because their actions affect others or others'actions affect them. "60 The number of players may vary widely, depending on the subject matter at issue, the preferences of states that are implicated, the information dynamics, the ability of states to organize to nfluence the development of legal rules, and other parameters. There will also be wide asymmetries of interest that reduce the effective number of players. Small states would ordinarily find it futile to try to influence the development of norms that interest lar states, unless the small states are able to form a coalition to press their interests. So,as we consider the number of players, we will make some simplifying assumptions Some of the leading authors in this field are skeptical of the possibility for multilateral customary processes to result in stable and efficient strategic equilibria under circumstances other than pure self-interest or coercion. For example, Goldsmith and Posner see little possibility for either coordination or cooperation(the term they use for resolution of a prisoner's dilemma) in multilateral settings. While they see the possibility for stable and efficient equilibria in certain bilateral settings, they assume that the bilateral prisoner's dilemma cannot in any event be generalized to the situation of multilateral cooperation, which is such an important part of the traditional account." b2 this connection, they follow an established tradition, led by mancur Olson in 1965: [U]nless the number of individuals in a group is quite small, or unless there is coercion or some other special device to make individuals act in their common interest. rational self-interested individuals will not act to achieve their common or group interests. Olson based his perspective on the assumptions that the benefit of cooperation declines with the number of players, that the costs of monitoring increase with the number of players, and that the costs of organizing retaliation increase with the number 65 of players. However, it can readily be seen that these are conjectures about the world, and are not necessarily true of any particular circumstance. Moreover, these are only a subset of the parameters worth considering. Finally, technological and social change has LAW 72-73(4 ed 1997); Edward T Swaine, The Local law of global Antitrust, 43 WM & MARY L.REV.627,706-25(2001) 60 Koremenos, Lipson& Nidal, supra note 32, at777 6I Goldsmith Posner 1999, supra note 2, at 1132 63 MANCUR OLSON, THE LOGIC OF COLLECTIVE ACTION 2(1965). See also Kenneth A Oye, Explaining Cooperation Under Anarchy: Hypotheses and Strategies, in COOPERATION UNDER ANARCHY(Kenneth A Oye, ed. 1986) Olson, supra note 63, at 48 RUSSELL HARDIN, COLLECTIVE ACTION 43(1982)The Customary International Law Supergame February 23, 2004 20 “Number of actors refers to the actors that are potentially relevant to joint welfare because their actions affect others or others’ actions affect them.” 60 The number of players may vary widely, depending on the subject matter at issue, the preferences of states that are implicated, the information dynamics, the ability of states to organize to influence the development of legal rules, and other parameters. There will also be wide asymmetries of interest that reduce the effective number of players. Small states would ordinarily find it futile to try to influence the development of norms that interest large states, unless the small states are able to form a coalition to press their interests. So, as we consider the number of players, we will make some simplifying assumptions. Some of the leading authors in this field are skeptical of the possibility for multilateral customary processes to result in stable and efficient strategic equilibria under circumstances other than pure self-interest or coercion. For example, Goldsmith and Posner see little possibility for either coordination or cooperation (the term they use for resolution of a prisoner’s dilemma) in multilateral settings. 61 While they see the possibility for stable and efficient equilibria in certain bilateral settings, they assume that "the bilateral prisoner's dilemma cannot in any event be generalized to the situation of multilateral cooperation, which is such an important part of the traditional account." 62 In this connection, they follow an established tradition, led by Mancur Olson in 1965: [U]nless the number of individuals in a group is quite small, or unless there is coercion or some other special device to make individuals act in their common interest, rational, self-interested individuals will not act to achieve their common or group interests. 63 Olson based his perspective on the assumptions that the benefit of cooperation declines with the number of players, that the costs of monitoring increase with the number of players, and that the costs of organizing retaliation increase with the number of players. 64 However, it can readily be seen that these are conjectures about the world, 65 and are not necessarily true of any particular circumstance. Moreover, these are only a subset of the parameters worth considering. Finally, technological and social change has LAW 72-73 (4 th ed. 1997); Edward T. Swaine, The Local Law of Global Antitrust, 43 WM. & MARY L. REV. 627, 706-25 (2001). 60 Koremenos, Lipson & Snidal, supra note 32, at 777. 61 Goldsmith & Posner 1999, supra note 2, at 1132. 62 Id. 63 MANCUR OLSON, THE LOGIC OF COLLECTIVE ACTION 2 (1965). See also Kenneth A. Oye, Explaining Cooperation Under Anarchy: Hypotheses and Strategies, in COOPERATION UNDER ANARCHY (Kenneth A. Oye, ed. 1986). 64 Olson, supra note 63, at 48. 65 RUSSELL HARDIN, COLLECTIVE ACTION 43 (1982)