微观经济学原理曼昆英文

TenPrinciplesofEconomicsEconomicsPRINCIPLESOFN.GregoryMankiw1Inthischapter,

lookfortheanswerstothesequestions:Whatkindsofquestionsdoeseconomicsaddress?Whataretheprinciplesofhowpeoplemakedecisions?Whataretheprinciplesofhowpeopleinteract?Whataretheprinciplesofhowtheeconomyasawholeworks?1TENPRINCIPLESOFECONOMICS2WhatEconomicsIsAllAboutScarcity:thelimitednatureofsociety’sresourcesEconomics:thestudyofhowsocietymanagesitsscarceresources,e.g.howpeopledecidewhattobuy,

howmuchtowork,save,andspendhowfirmsdecidehowmuchtoproduce,

howmanyworkerstohirehowsocietydecideshowtodivideitsresourcesbetweennationaldefense,consumergoods,protectingtheenvironment,andotherneeds00Theprinciplesof

HOWPEOPLE

MAKEDECISIONSTENPRINCIPLESOFECONOMICS4HOWPEOPLEMAKEDECISIONSAlldecisionsinvolvetradeoffs.Examples:Goingtoapartythenightbeforeyourmidtermleaveslesstimeforstudying.Havingmoremoneytobuystuffrequiresworkinglongerhours,whichleaveslesstimeforleisure.Protectingtheenvironmentrequiresresources

thatcouldotherwisebeusedtoproduce

consumergoods.Principle#1:PeopleFaceTradeoffs0TENPRINCIPLESOFECONOMICS5HOWPEOPLEMAKEDECISIONSSocietyfacesanimportanttradeoff:

efficiencyvs.equalityEfficiency:whensocietygetsthemostfromitsscarceresourcesEquality:whenprosperityisdistributeduniformlyamongsociety’smembersTradeoff:Toachievegreaterequality,

couldredistributeincomefromwealthytopoor.

Butthisreducesincentivetoworkandproduce,shrinksthesizeoftheeconomic“pie.”Principle#1:PeopleFaceTradeoffs0TENPRINCIPLESOFECONOMICS6HOWPEOPLEMAKEDECISIONSMakingdecisionsrequirescomparingthecostsandbenefitsofalternativechoices.Theopportunitycostofanyitemis

whatevermustbegivenuptoobtainit.Itistherelevantcostfordecisionmaking.Principle#2:TheCostofSomethingIs

WhatYouGiveUptoGetItTENPRINCIPLESOFECONOMICS7HOWPEOPLEMAKEDECISIONS

Examples:

Theopportunitycostof……goingtocollegeforayearisnotjustthetuition,books,andfees,butalsotheforegonewages.…seeingamovieisnotjustthepriceoftheticket,

butthevalueofthetimeyouspendinthetheater.Principle#2:TheCostofSomethingIs

WhatYouGiveUptoGetItTENPRINCIPLESOFECONOMICS8HOWPEOPLEMAKEDECISIONSRationalpeople

systematicallyandpurposefullydothebesttheycantoachievetheirobjectives.makedecisionsbyevaluatingcostsandbenefitsofmarginalchanges

–incrementaladjustmentstoanexistingplan.Principle#3:RationalPeopleThinkattheMarginTENPRINCIPLESOFECONOMICS9HOWPEOPLEMAKEDECISIONSExamples:Whenastudentconsiderswhethertogotocollegeforanadditionalyear,hecomparesthefees&foregonewagestotheextraincome

hecouldearnwiththeextrayearofeducation.Whenamanagerconsiderswhethertoincreaseoutput,shecomparesthecostoftheneededlaborandmaterialstotheextrarevenue.Principle#3:RationalPeopleThinkattheMarginTENPRINCIPLESOFECONOMICS10HOWPEOPLEMAKEDECISIONSIncentive:somethingthatinducesapersontoact,i.e.theprospectofarewardorpunishment.Rationalpeoplerespondtoincentives. Examples:Whengaspricesrise,consumersbuymorehybridcarsandfewergasguzzlingSUVs.Whencigarettetaxesincrease,

teensmokingfalls.Principle#4:PeopleRespondtoIncentivesYouaresellingyour1996car.Youhavealreadyspent$1000onrepairs.Atthelastminute,thetransmissiondies.Youcanpay$600tohaveitrepaired,orsellthecar“asis.”Ineachofthefollowingscenarios,shouldyouhavethetransmissionrepaired?Explain.A.

Bluebookvalueis$6500iftransmissionworks,

$5700ifitdoesn’tB.

Bluebookvalueis$6000iftransmissionworks,

$5500ifitdoesn’tACTIVELEARNING1

Applyingtheprinciples11Costoffixingtransmission=$600A. Bluebookvalueis$6500iftransmissionworks,

$5700ifitdoesn’t

Benefitoffixingthetransmission=$800

($6500–5700). It’sworthwhiletohavethetransmissionfixed.

B. Bluebookvalueis$6000iftransmissionworks,

$5500ifitdoesn’t

Benefitoffixingthetransmissionisonly$500. Paying$600tofixtransmissionisnotworthwhile.ACTIVELEARNING1

Answers12Observations:The$1000youpreviouslyspentonrepairsisirrelevant.Whatmattersisthecostandbenefit

ofthemarginalrepair(thetransmission).ThechangeinincentivesfromscenarioA

toscenarioBcausedyourdecisiontochange.ACTIVELEARNING1

Answers130Theprinciplesof

HOWPEOPLE

INTERACTTENPRINCIPLESOFECONOMICS15HOWPEOPLEINTERACTRatherthanbeingself-sufficient,

peoplecanspecializeinproducingonegoodorserviceandexchangeitforothergoods.Countriesalsobenefitfromtrade&specialization:GetabetterpriceabroadforgoodstheyproduceBuyothergoodsmorecheaplyfromabroadthancouldbeproducedathomePrinciple#5:TradeCanMakeEveryone

BetterOffTENPRINCIPLESOFECONOMICS16HOWPEOPLEINTERACTMarket:agroupofbuyersandsellers

(neednotbeinasinglelocation)“Organizeeconomicactivity”meansdeterminingwhatgoodstoproducehowtoproducethemhowmuchofeachtoproducewhogetsthemPrinciple#6:MarketsAreUsuallyAGoodWaytoOrganizeEconomicActivityTENPRINCIPLESOFECONOMICS17HOWPEOPLEINTERACTAmarketeconomyallocatesresourcesthroughthedecentralizeddecisionsofmanyhouseholdsandfirmsastheyinteractinmarkets.FamousinsightbyAdamSmithin

TheWealthofNations(1776): Eachofthesehouseholdsandfirms

actsasif“ledbyaninvisiblehand”

topromotegeneraleconomicwell-being.Principle#6:MarketsAreUsuallyAGoodWaytoOrganizeEconomicActivityTENPRINCIPLESOFECONOMICS18HOWPEOPLEINTERACTTheinvisiblehandworksthroughthepricesystem:Theinteractionofbuyersandsellers

determinesprices.Eachpricereflectsthegood’svaluetobuyersandthecostofproducingthegood.Pricesguideself-interestedhouseholdsandfirmstomakedecisionsthat,inmanycases,maximizesociety’seconomicwell-being.Principle#6:MarketsAreUsuallyAGoodWaytoOrganizeEconomicActivityTENPRINCIPLESOFECONOMICS19HOWPEOPLEINTERACTImportantroleforgovt:enforcepropertyrights

(withpolice,courts)Peoplearelessinclinedtowork,produce,invest,orpurchaseiflargeriskoftheirpropertybeingstolen.Principle#7:GovernmentsCanSometimesImproveMarketOutcomesTENPRINCIPLESOFECONOMICS20HOWPEOPLEINTERACTMarketfailure:whenthemarketfailstoallocatesociety’sresourcesefficientlyCauses:Externalities,whentheproductionorconsumption

ofagoodaffectsbystanders(e.g.pollution)Marketpower,asinglebuyerorsellerhassubstantialinfluenceonmarketprice(e.g.monopoly)Insuchcases,publicpolicymaypromoteefficiency.Principle#7:GovernmentsCanSometimesImproveMarketOutcomesTENPRINCIPLESOFECONOMICS21HOWPEOPLEINTERACTGovtmayaltermarketoutcometopromoteequityIfthemarket’sdistributionofeconomicwell-being

isnotdesirable,taxorwelfarepoliciescanchangehowtheeconomic“pie”isdivided.Principle#7:GovernmentsCanSometimesImproveMarketOutcomes0Theprinciplesof

HOWTHEECONOMY

ASAWHOLEWORKSTENPRINCIPLESOFECONOMICS23HOWTHEECONOMYASAWHOLEWORKSHugevariationinlivingstandardsacrosscountriesandovertime:Averageincomeinrichcountriesismorethantentimesaverageincomeinpoorcountries.TheU.S.standardoflivingtodayisabout

eighttimeslargerthan100yearsago.Principle#8:Acountry’sstandardoflivingdependsonitsabilitytoproducegoods&services.TENPRINCIPLESOFECONOMICS24HOWTHEECONOMYASAWHOLEWORKSThemostimportantdeterminantoflivingstandards:productivity,theamountofgoodsandservicesproducedperunitoflabor.Productivitydependsontheequipment,skills,andtechnologyavailabletoworkers.Otherfactors(e.g.,laborunions,competitionfromabroad)havefarlessimpactonlivingstandards.Principle#8:Acountry’sstandardoflivingdependsonitsabilitytoproducegoods&services.TENPRINCIPLESOFECONOMICS25HOWTHEECONOMYASAWHOLEWORKSInflation:increasesinthegenerallevelofprices.Inthelongrun,inflationisalmostalwayscausedbyexcessivegrowthinthequantityofmoney,whichcausesthevalueofmoneytofall.Thefasterthegovtcreatesmoney,

thegreatertheinflationrate.Principle#9:Pricesrisewhenthegovernmentprintstoomuchmoney.TENPRINCIPLESOFECONOMICS26HOWTHEECONOMYASAWHOLEWORKSIntheshort-run(1–2years),

manyeconomicpoliciespushinflationandunemploymentinoppositedirections.Otherfactorscanmakethistradeoffmoreorlessfavorable,butthetradeoffisalwayspresent.Principle#10:Societyfacesashort-runtradeoffbetweeninflationandunemploymentTENPRINCIPLESOFECONOMICS27FYI:HowtoReadYourTextbook1.

Readbeforeclass.

You’llgetmoreoutofclass.2.

Summarize,don’thighlight.

Highlightingisapassiveactivitythatwon’timproveyourcomprehensionorretention.

Instead,summarizeeachsectioninyourownwords.Then,compareyoursummarytotheone

attheendofthechapter.TENPRINCIPLESOFECONOMICS28FYI:HowtoReadYourTextbook3. Testyourself.

Trythe“QuickQuiz”thatfollowseachsectionbeforemovingontothenextsection.

Writeyouranswersdown,comparethemtotheanswersinthebackofthebook.Ifyouranswersareincorrect,reviewthesectionbeforemovingon.4.

Practice,practice,practice.

Workthroughtheend-of-chapterreviewquestionsandproblems.Theyareoftengoodpracticefortheexams.Andthemoreyouuseyournewknowledge,themoresoliditwillbecome.TENPRINCIPLESOFECONOMICS29FYI:HowtoReadYourTextbook5. Goonline.

Thebookcomeswithexcellentwebresources,includingpracticequizzes,toolstostrengthenyourgraphingskills,helpfulvideoclips,andotherresourcestohelpyoulearnthetextbookmaterialmoreeasilyandeffectively.Visit:

6.

Studyingroups.

Gettogetherwithafewclassmatestorevieweachchapter,quizeachother,andhelpeachotherunderstandthematerial.TENPRINCIPLESOFECONOMICS30FYI:HowtoReadYourTextbook7.

Teachsomeone.

Thebestwaytolearn