数据系统和主要的代理模式概述英文

InformationSystemsunderPrincipal-agentModeling

Dr.Chak-TongChau

仇澤棠博士U.S.FulbrightProfessor中美交流富布萊特教授WhatIsInformation?

Broadlydefined,informationisanydevicethathelpstoreduceuncertainty. Alternatively,informationshouldbehelpfulin:detectingthecurrentstateoftheworld,orforecastingthefuturestateoftheworldDr.Chak-TongChau2FulbrightGuestLectureMaterialsGoodInformationShouldbeUsefulin:Improvingproductiondecisions–tellingustodotherightthings.Optimizingthescopeforrisksharing–sothatsomepeoplecannotmakeprofitsbyharmingotherpeople.Eliminating“informationasymmetry”–sothatexante(before-the-act)privateinformationcanbeknownexpost(after-the-act).Dr.Chak-TongChau3FulbrightGuestLectureMaterialsTimelineofatypicalagencycontractContractagreedEffortselectedPayoffrevealedPre-contractinformationPre-effortselectioninformationPost-effortinformationPost-payoffinformationTimingInformationAvailabilityToagentonly(private)Toallparties(public)Pre-contractAgent’sproprietaryknowledgeHistoricalinformationPost-contract,pre-effortInformationsetunderdecentralizationPost-effort,pre-payoffVoluntarydisclosure–relevationprinciplePostpayoff(expost)NotinterestingFinancialreportingDr.Chak-TongChau4FulbrightGuestLectureMaterialsUsefulnessofInformationHowdoweknow,apriori,thatinformationis“useful”?Considerthefollowingpayoffstructure(knowntoall):EffortS1S2S3S4S5S6ExpectedPayoffe1=102334553.67e2=52234453.33Dr.Chak-TongChau5FulbrightGuestLectureMaterialsUsefulnessofInformationNow,wehaveaninformationsystemthatwillgeneratethesesignals:{S1,S2,S3}{S4,S5,S6}Y1Y2Signal:Y1Y2S1S2S3S4S5S6e1=10233455e2=5223445Inasense,theinformationsystempartitionsthematrixasfollowsQuestion:Arethesignals,Y1andY2,useful?Dr.Chak-TongChau6FulbrightGuestLectureMaterialsUsefulnessofInformationNow,wehaveanotherinformationsystemthatwillgeneratethesesignals:{S1}{S4,S5,S6}Y1Y3Signal:Y1Y2Y3S1S2S3S4S5S6e1=10233455e2=5223445ThisnewinformationsystempartitionsthematrixasfollowsQuestion:Arethesignals,Y1,,Y2andY3useful?{S2,S3}Y2Dr.Chak-TongChau7FulbrightGuestLectureMaterialsCanPrivateInformationtoAgentBenefitthePrincipal?Considerthefollowingpayoffstructure(knowntoall):S1S2S3S4ExpectedPayofftoPrincipalbeforePaymenttoAgentProb.50.25e1=000000e2=520,00020,00025,00030,00023,750e2=620,00030,00030,00035,00028,750Agent’sUtilityFunction:

U=X½-e2

100where: X=agent’scompensations e=theeffortlevelusedbytheagentIfthePrincipalcanobserveeffort,howwouldhepaytheagent?X½-62=100X

=18,496Dr.Chak-TongChau8FulbrightGuestLectureMaterialsCanPrivateInformationtoAgentBenefitthePrincipal?Now,ifthePrincipalcannotobserveeffort,howwouldhepaytheagent?Howaboutthiscompensationcontract(afixedsalaryof$18,496)toagent?Wouldthiswork?S1S2S3S4ExpectedUtilitytoAExpectedPayofftoPProb.50.25e1=018,49618,49618,49618,496e2=518,49618,49618,49618,496e3=618,49618,49618,49618,496136111100-18,4965,254

10,254Thus,afixedsalarytosomeonewhomyoucannotobservewon’twork.A“moralhazard”problemwillcomeintoplay.Dr.Chak-TongChau9FulbrightGuestLectureMaterialsCanPrivateInformationtoAgentBenefitthePrincipal?Nowthen,whataboutacontingentsalaryof$18,496toagent?WouldthisimprovethePrincipal’spayoff?S1S2S3S4ExpectedUtilitytoAExpectedPayofftoPProb.50.25e1=00000e2=518,49618,496018,496e3=618,49618,49618,49618,496

07710009,878

10,254Now,thecontingentsalarycontractwillimprovebyforcingtheAgenttogive(e3=6).Letusnowlookatthe“privateinformationtoagent”issue!Dr.Chak-TongChau10FulbrightGuestLectureMaterialsCanPrivateInformationtoAgentBenefitthePrincipal?Thisprivateinformationsystem(onlyobservabletotheagent)generatesthesesignals:{S1,S2}{S3,S4}Y1Y2Wouldthecontingentsalaryof$18,496toagentstillwork?Signal:Y1Y2ExpectedUtilitytoAgentwithPrivateinfoExpectedPayofftoPrincipalwithPrivateinfoS1S2S3S4Prob.50.25e1=00000e2=518,49618,496018,496105.5(100)7,754(10,254)e3=618,49618,49618,49618,496Dr.Chak-TongChau11FulbrightGuestLectureMaterialsCanPrivateInformationtoAgentBenefitthePrincipal?Now,thenewprivateinformationmakesiteasyfortheagenttocheat.So,whatshouldtheprincipaldo?Considerthisnewcontingentcontract(correspondingpayoffs):S1S2S3S4Prob.50.25e1=00000e2=514,722(20,000)14,722(20,000)

0(25,000)20,544(30,000)e3=614,722(20,000)20,544(30,000)20,544(30,000)18,496(35,000)Wouldthenewplanwork?Letuscalculatetheagent’sutilityandtheprincipal’spayoff.Dr.Chak-TongChau12FulbrightGuestLectureMaterialsS1S2S3S4ExpectedUtilitytoAExpectedPayofftoPProb.50.25e1=00000e2=514,722(20,000)14,722(20,000)

0(25,000)20,544(30,000)e3=614,722(20,000)20,544(30,000)20,544(30,000)18,496(35,000)071.51000n/a10,173.5Summaryofresults:TypesofcontractPrincipal’sPayoffsAgent’sUtilityFixedsalary,effortobservable10,254100.0Fixedsalary,effortunobservable-18,496136.0Contingentsalary,noprivateinformation10,254100.0One-amount,withprivateinformation7,754105.5Multiple-amount,withprivateinformation10,173.5100.0Dr.Chak-TongChau13FulbrightGuestLectureMaterialsPre-effort“Public”Information?Thistime,itisdifferentinthattheinformationisavailabletoall,principalandagent.(changed)S1S2S3S4Prob.50.25e1=00000e2=520,000(18,496)25,000(0)25,000(0)30,000(18,496)e2=620,000(18,496)30,000(18,496)30,000(18,496)35,000(18,496)Thispublicinformationsystem(observabletoall)generatesthesesignals:{S1,S2}{S3,S4}Y1Y2Isthisinformationusefultotheagent?Dr.Chak-TongChau14FulbrightGuestLectureMaterialsSignal:Y1Y2ExpectedUtilitytoAgentExpectedPayofftoPrincipalS1S2S3S4Prob.50.25e1=00000e2=518,4960018,49610010,254e3=618,49618,49618,49618,496First,theinformationhasnovaluetotheagent.Why?Thisisbecausetheagent,byobservingY1,cannotguarranteethatthepayoff$25,000willnotoccur.However,isthiskindofinformationsystemusefultothePrincipal?Dr.Chak-TongChau15FulbrightGuestLectureMaterialsNow,letuslookatthisnewcontract(correspondingpayoffs):Signal:Y1Y2S1S2S3S4Prob.50.25e1=00000e2=515,170(20,000)15,170(25,000)

15,170(25,000)17,030(30,000)e3=615,170(20,000)17,030(30,000)17,030(30,000)21,074(35,000)Now,ifY1isobserved,whatwouldtheagentdo?U(e2)=15,1701/2–52=98.17U(e3)=15,1701/2*0.5+17,0301/2*0.5––62=90.89Thus,thePrincipalinfacttellstheagenttobelazy!Dr.Chak-TongChau16FulbrightGuestLectureMaterialsSignal:Y1Y2S1S2S3S4Prob.50.25e1=00000e2=515,170(20,000)15,170(25,000)

15,170(25,000)17,030(30,000)e3=615,170(20,000)17,030(30,000)17,030(30,000)21,074(35,000)Then,ifY2isobserved,whatwouldtheagentdo?U(e2)=15,1701/2*0.5+17,0301/2*0.5––52=101.88U(e3)=17,0301/2*0.5+21,0741/2*0.5––62=102.03Thistime,theagentwillwanttoworkhard.Onaverage,98.17*0.5+102.03*0.5=100So,thisisacceptabletotheagent.Dr.Chak-TongChau17FulbrightGuestLectureMaterialsButforthePrincipal,whyshouldhecare?Signal:Y1Y2S1S2S3S4Prob.50.25e2=520,00025,000

e3=630,00035,000WagestoA(15,170)(15,170)(17,030)(21,074)ExpectedResidual1,207.502,457.503,242.503,481.5010,389Notethatthisislargerthan10,254,theoptimalsolutionunderperfectinformation.Thus,seeminglyuselessinformationcanbeuseful!Dr.Chak-TongChau18FulbrightGuestLectureMaterialsInConclusion,Wecannotguarranteethatpeoplewillalwaysdotheethicallycorrectthings.Therefore,theywillhavetobemonitoredandcontrolled.Informationsystemsprovideuswiththemeansto:informuswhathashappened,andmotivatepeopletodotheethicallycorrectthings.Itisthereforeimportanttoconsiderthesepointsindesigninganymanagerialaccountingsystems.Dr.Chak-TongChau19FulbrightGuestLectureMaterials9、静夜四无无邻，荒居居旧业贫。。。1月-231月-23Friday,January6,202310、雨中黄叶叶树，灯下下白头人。。。01:08:4801:08:4801:081/6/20231:08:48AM11、以我独沈久久，愧君相见见频。。1月-2301:08:4801:08Jan-2306-Jan-2312、故故人人江江海海别别，，几几度度隔隔山山川川。。。。01:08:4801:08:4801:08Friday,January6,202313、乍见见翻疑疑梦，，相悲悲各问问年。。。1月-231月-2301:08:4801:08:48January6,202314、他乡生白发发，旧国见青青山。。06一月20231:08:48上午01:08:481月-2315、比不了得就就不比，得不不到的就不要要。。。一月231:08上上午1月-2301:08January6,202316、行动出出成果，，工作出出财富。。。2023/1/61:08:4801:08:4806January202317、做前，能够够环视四周；；做时，你只只能或者最好好沿着以脚为为起点的射线线向前。。1:08:48上午1:08上上午01:08:481月-239、没没有有失失败败，，只只有有暂暂时时停停止止成成功功！！。。1月-231月-23Friday,January6,202310、很多事事情努力力了未必必有结果果，但是是不努力力却什么么改变也也没有。。。01:08:4801:08:4801:081/6/20231:08:48AM11、成成功功就就是是日日复复一一日日那那一一点点点点小小小小努努力力的的积积累累。。。。1月月-2301:08:4801:08Jan-2306-Jan-2312、世间成事，，不求其绝对对圆满，留一一份不足，可可得无限完美美。。01:08:4801:08:4801:08Friday,January6,202313、不知香香积寺，，数里入入云峰。。。1月-231月-2301:08:4801:08:48January6,202314、意志坚坚强的人人能把世世界放在在手中像像泥块一一样任意意揉捏。。06一一月20231:08:48上午午01:08:481月-2315、楚塞三