理性预期（rational expectations)

main differences between rational and adaptive expectations．What does each implv about the effectiveness of macroeconomic policy？

解释为什么如果消费者遵循持久收入假说而又有理性预期，消费的变动就是不可预期的。

Explain why changes in consumption are unpredictable if consumers obey the permanent-income hypothesis and have rational expectations.

们迅速调整通货膨胀预期； c．政府享有无力削减支出的名声； d．人们具有理性而非适应性的预期。 Discuss how the following circumstances affect the Value of the sacrifice ratio and the amount of inertial inflation in the economy： a．Long—term contracts are pervasiVe in the economy． b．People adjust their inflationary expectations very fast． c．The government has a reputation of not being able to reduce its expenditures． d．People have rational rather than adaptiVe expectations．

判断下列说法是否错误？ (1)如果一个社会中的每个消费者的偏好都是理性(rational)的，那么按照多数票原则决定的集体偏好也一定是理性的。 (2)优超策略均衡一定属于纳什均衡。 (3)“斯塔格博格(Stackelberg)产量领导者所获得的利润的下限是古诺均衡下它得到的利润。” (4)“由于两个罪犯只打算合伙犯罪一次，所以被捕后才出现了不合作的问题即囚徒困境(prisoners’dilemma)，所以如果他们打算重复合伙多次，比如说20次那么对策论预测他们将采取彼此合作的态度，即谁都不招供。”