可以把美国和日本的贸易政策看作一个囚徒困境。这两个国家正在研究开放还是封闭它们的重要市场

(1)设各国都了解该支付矩阵并相信另一国会根据它自己的利益行事。两个国家都有一个占优策略吗？如果各国都为了最大化其福利而采取理性的行为，均衡政策将是什么？

(2)现在假设日本不能肯定美国一定会表现得很理性。特别是，日本担心美国政治家即.使不能最大化美国的福利也要惩罚日本。这将如何影响日本的策略选择？这将如何改变均衡？

We can think of the U. s. and Japanese trade policies as a Prisoners' Dilemma. The two countries are considering policies to open or close their import markets. Suppose the payoff matrix is:

a Assume that each country knows the payoff matrix and believes that the other country will act in its own interest. Does either country have a dominant strategy？ What will the equilibrium policies if each country acts rationally to maximize its welfare？

b. Now amuse that Japan is mot certain that the u.s. will behave ration.In particular Japan is concerned that U. S. g politicians may want to penalize Japan even if that does not maximize

U. S. welfare. How might this affect Japan' s choice of strategy？ How might this change the equilibrium？