微观经济学前沿(经济学原理曼昆中英文双语)

22,Frontiers of Microeconomics微观经济学前沿,ASYMMETRIC INFORMATION不对称信息,A difference in access to relevant knowledge is called information asymmetry. 获得相关知识的差别被称为信息不对称。,Hidden Actions: Principals, Agents, and Moral Hazard,Moral HazardMoral 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.,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,Hidden Actions: Principals, Agents, and Moral Hazard,Moral HazardAn 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.,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。,Hidden Actions: Principals, Agents, and Moral Hazard,Adverse SelectionAdverse selection refers to the tendency for the mix of unobserved attributes to become undesirable from the standpoint of an uniformed party.,隐蔽性行为:委托人、代理人及道德危险,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。,Hidden 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 healthIn certain labor markets, if a firm reduces the wage it pays, high productivity workers tend to quit.,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。,Signaling to Convey Private Information,How do Markets respond to Asymmetric Information?SignalingSignaling refers to an action taken by an informed party to reveal private information to an uninformed party.ScreeningScreening occurs when an action taken by an uniformed party induces an informed party to reveal information.,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。,Asymmetric 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。,Asymmetric 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。,Asymmetric 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 ownThe government rarely has more information than the private parties.The government itself is an imperfect institution,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。,POLITICAL ECONOMY政治经济学,Political economy (public 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。,POLITICAL ECONOMY,Problems Associated with How Government Determines Public PolicyThe Condorcet ParadoxArrows Impossibility TheoremThe Median-Voter TheoremSelf-interested Politicians,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,The Condorcet Voting Paradox,Third choice,Second choice,First choice,Percent of electorate,Type 3,Type 2,Type 1,Voter Type,孔多塞投票悖论,第三次选择,第二次选择,第一次选择,选民的百分比,3类,2类,1类,选民类型,The 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.,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。,Arrows Impossibility Theorem,Arrows impossibility theorem is a mathematical result which shows that, under certain conditions, there is no scheme for aggregating individual preferences into a valid set of social preferences.,阿罗不可能性定理,阿罗不可能性定理 数学结论表明，在某些假设条件下，没有一种方案能把个人偏好加总为一组正确的社会偏好。,Arrows Impossibility Theorem,No Voting System Can Satisfy All of the FollowingUnanimityTransitivityIndependence of irrelevant alternativesNo dictators,阿罗不可能性定理,没有一种投票机制满足以下所有条件确定性传递性其他不相关选择的独立性没有独裁者,Median Voter Theorem,The median voter theorem is a mathematical result that shows that if voters are choosing a point along a line and each voter wants the point closest to his most preferred point, then majority rule will pick the most preferred point of the median voter.,中值选民定理,中值选民定理 一个数学结论，表明要选民沿着一条线选一个点，而且每个选民都想选离他最偏好的点最近的点，那么多数规则将选择中值选民最偏好的点。,Politicians Are People Too政治家也是人,Some politicians are motivated by self-interest. 一些政治家也受自利所驱使。Some politicians sacrifice the national interest to solidify their base of voters. 一些政治家牺牲国家利益来巩固他们的选民基础。,BEHAVIORAL ECONOMICS行为经济学,