曼昆《經(jīng)濟學原理》frontiers--(漢魅HanMei—經(jīng)濟金融類匯總分享)

1、Copyright 2004 South-WesternFrontiers of Microeconomics Copyright 2004 South-WesternASYMMETRIC INFORMATION A difference in access to relevant knowledge is called .Copyright 2004 South-WesternHidden Actions: Principals, Agents, and Moral Hazard Moral hazard refers to the tendency of a person who is i

2、mperfectly 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-WesternHidden Actions: Principals, Agents, and Moral Hazard An agent is a person who i

3、s 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-WesternHidden Actions: Principals, Agents, and Moral Hazard Adverse selection refers to the tendency for the mix of unobserv

4、ed attributes to become undesirable from the standpoint of an uniformed party.Copyright 2004 South-WesternHidden Actions: Principals, Agents, and Moral Hazard Example of Adverse Selection: Many time potential buyers may not even consider used cars because they surmise that the sellers know something

5、 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 S

6、outh-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

7、 an informed party to reveal information.Copyright 2004 South-WesternAsymmetric Information and Markets The study of asymmetric information gives us new reason to be wary of markets.Copyright 2004 South-WesternAsymmetric Information and Public Policy When some people know more than others do, the ma

8、rket may fail to put the resources to their best uses.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 Th

9、e government rarely has more information than the private parties. The government itself is an imperfect institutionCopyright 2004 South-WesternPOLITICAL ECONOMY Political economy ( ) is the application of economic methods to the study of how government works.Copyright 2004 South-WesternPOLITICAL EC

10、ONOMY Problems Associated with How Government Determines Public Policy The Condorcet Paradox Arrows Impossibility Theorem The Median-Voter Theorem Self-interested PoliticiansCopyright 2004 South-WesternThe Condorcet Voting ParadoxThird choiceSecond choiceFirst choicePercent of electorateType 3Type 2

11、Type 1Voter TypeCopyright 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

12、 South-WesternArrows 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.Copyright 2004 South-WesternArrows Impossibility Theorem No Vo

13、ting System Can Satisfy All of the Following Unanimity Transitivity Independence of irrelevant alternatives No dictatorsCopyright 2004 South-WesternMedian 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

14、the point closest to his most preferred point, then majority rule will pick the most preferred point of the median voter.Copyright 2004 South-WesternBEHAVIORAL ECONOMICS Recently, a field called behavioral economics has emerged in which economists make use of basic psychological insights to examine

15、economic problems.Copyright 2004 South-WesternPoliticians Are People Too Some politicians are motivated by self-interest. Some politicians sacrifice the national interest to solidify their base of voters.Copyright 2004 South-WesternBEHAVIORAL ECONOMICS People arent always rational: People are overco

16、nfident People give too much weight to a small number of vivid observations People are reluctant to change their minds. People care about fairness as demonstrated by the ultimatum game People are inconsistent over time.Copyright 2004 South-WesternSummary In many economic transactions, information is

17、 asymmetric. When there are hidden actions, principals may be concerned that agents suffer from the problem of moral hazard. When there are hidden characteristics, buyers may be concerned about the problems of adverse selection among sellers. Private markets sometimes deal with asymmetric informatio

18、n with signaling and screening.Copyright 2004 South-WesternSummary Although government policy can sometimes improve market outcomes, governments are themselves imperfect institutions. The Condorcet paradox shows that majority rule may fail to produce transitive preferences for society. Arrows impossibility theorem sho