微观经济学前沿经济学原理曼昆中英文双语

Copyright © 2004 South-Western22Frontiers of Microeconomics微观经济学前沿 Copyright © 2004 South-WesternASYMMETRIC INFORMATION 不对称信息 A difference in access to relevant knowledge is called information asymmetryinformation asymmetry.获得相关知识的差别被称为信息不对称。Copyright © 2004 South-WesternHidden Actions: Principals, Agents,and Moral Hazard Moral HazardMoral Hazard Moral hazard refers to the tendency of a person who is imperfectly monitored to engage in dishonest or otherwise undesirable behavior. Employers can respond to the moral-hazard problem in various ways: Better monitoring. High wages. Delayed payment.Copyright © 2004 South-Western隐蔽性行为:委托人、代理人及道德危险 道德危险 道德危险 一个没有受到完全监督的 人从事不忠诚或不合意行为的倾向。 雇主可以用各种办法对这个问题做出反 应： 更好的监督 高工资 延期支付Copyright © 2004 South-WesternHidden Actions: Principals, Agents, and Moral Hazard Moral HazardMoral Hazard An agent is a person who is performing an act for another person, called the principal. The principal is a person for whom another person, called the agent, is performing some act. Copyright © 2004 South-Western隐蔽性行为:委托人、代理人及道德危险 道德危险 代理人 一个为委托人完成某种行为的人。 委托人 让代理人完成某种行为的人。Copyright © 2004 South-WesternHidden Actions: Principals, Agents,and Moral Hazard Adverse SelectionAdverse Selection Adverse selection refers to the tendency for the mix of unobserved attributes to become undesirable from the standpoint of an uniformed party.Copyright © 2004 South-Western隐蔽性行为:委托人、代理人及道德危险 逆向选择逆向选择 逆向选择 从缺乏信息一方的角度看，无法观察到的特征混合变为不合意的倾向。Copyright © 2004 South-WesternHidden Actions: Principals, Agents, and Moral Hazard Example of Adverse Selection: Many times potential buyers may not even consider used cars because they surmise that the sellers know something bad about the cars. This is also known as the lemons problem. InsurancePeople with hidden health problems are more likely to want to buy health insurance than those with good health In certain labor markets, if a firm reduces the wage it pays, high productivity workers tend to quit.Copyright © 2004 South-Western隐蔽性行为:委托人、代理人及道德危险 逆向选择的例子： 很多时候，潜在的买者也许根本不考虑购买二手车，因为他们猜测卖者知道车的毛病所在。 这就是著名的柠檬问题。. 保险有严重隐蔽性健康问题的人比其他正常健康的人更可能购买医疗保险。 在一些劳动市场上，如果企业降低它支付的工资，能力较强的工人就会离去。Copyright © 2004 South-WesternSignaling to Convey Private Information How do Markets respond to Asymmetric Information? Signaling Signaling refers to an action taken by an informed party to reveal private information to an uninformed party. Screening Screening occurs when an action taken by an uniformed party induces an informed party to reveal information.Copyright © 2004 South-Western为传递私人信息发信号 市场如何对不对称信息做出反应？ 信号 信号 有信息的一方向无信息的一方披露自己私人信息所采取的行动。 筛选 筛选 无信息的一方引起有信息的一方披露信息所采取的行动。Copyright © 2004 South-WesternAsymmetric Information and Markets不对称信息与市场 The study of asymmetric information gives us new reason to be wary of markets.不对称信息的研究给了我们一个留心市场的新理由。Copyright © 2004 South-WesternAsymmetric Information and Public Policy不对称信息与公共政策 When some people know more than others do, the market may fail to put the resources to their best uses.当一些人知道的比另一些人多时，市场也不能使资源得到最好的利用。Copyright © 2004 South-WesternAsymmetric Information and Public Policy Although asymmetric information may call for government action, three facts complicate the issue: Private markets can sometimes deal with information asymmetries on their own The government rarely has more information than the private parties. The government itself is an imperfect institutionCopyright © 2004 South-Western不对称信息与公共政策 尽管不对称信息可以在一些情况下要求 政府有所作为，但三个事实使这个问题 复杂化了： 私人市场有时可以依靠自己解决信息不对 称问题。 政府也并不比私人各方有更多信息。 政府本身也是一种不完善的制度。Copyright © 2004 South-WesternPOLITICAL ECONOMY 政治经济学 Political economy (public choicepublic choice ) is the application of economic methods to the study of how government works.政治经济学（有时称为公共选择学科）运用经济学的方法来研究政府如何运行。Copyright © 2004 South-WesternPOLITICAL ECONOMY Problems Associated with How Government Determines Public Policy The Condorcet Paradox Arrows Impossibility Theorem The Median-Voter Theorem Self-interested PoliticiansCopyright © 2004 South-Western政治经济学 与政府如何决定公共政策有关的问题 孔多塞投票悖论 阿罗不可能性定理 中值选民理论 自利的政治家Copyright © 2004 South-WesternThe Condorcet Voting ParadoxThird choiceSecond choiceFirst choiceB BA AC CA AC CB BC CB BA A202045453535Percent of electorateType 3Type 2Type 1Voter TypeCopyright © 2004 South-Western孔多塞投票悖论第三次选择第二次选择第一次选择B BA AC CA AC CB BC CB BA A202045453535选民的百分比3类2类1类选民类型Copyright © 2004 South-WesternThe Condorcet Voting Paradox The Condorcet Paradox occurs when the majority rule fails to produce transitive preferences for society. Transitive preferences imply that if A is preferred to B, and B is preferred to C, then A is preferred to C.Copyright © 2004 South-Western孔多塞投票悖论 孔多塞悖论多数规则没有产生可传递性的社会偏好。 传递性偏好意思是，如果A优于B，而B优于C，则A 优于C。Copyright © 2004 South-WesternArrows Impossibility Theorem Arrows impossibility theorem is a mathematical result which shows that, under certain conditions, there is no