微觀濟學(xué)八章壟斷競爭與寡頭市場作業(yè)題答案印過ans d8 l08

1Qc，對此例來講，就是1/6Qc，而由1200-2Q=MC=0得n所以均衡時每家企業(yè)的產(chǎn)量為1002.32-+322LTC=0.01Q-0.8Q+20QLAC=0.01Q-2壟斷競爭市場長期均衡時，P=LAC即：21-0.8Q=0.01Q0.8Q+20∵dLAC/dQ=0.02Q-∴（10，13）在LAC的斜率為k=0.02*10-0.8=-∴主觀需求曲線的表達式為：P=-0.6（Q-10）+13=19-英文教科書Nicholson,Chapter19problem19.2Amonopolistcanproduceatconstantaverage(and英文教科書Nicholson,Chapter19problem19.2Amonopolistcanproduceatconstantaverage(andmarginal)costofAC=MC=5.ThefirmfacesamarketdemandcurvegivenbyQ=53-Calculatetheprofit-maximizingprice-quantitycombinationforthismonopolist.Alsocalculatethemonopolist’sprofits.Supposeasecondfirmentersthemarket.Letq1betheoutputoffirm1andq2.Marketdemandnowisgivenbyq1+q2=53-Assumingfirm2hasthesamecostsasfirm1,calculatetheprofitsoffirms1and2asfunctionsofq1andq2.Suppose(afterCournot)eachofthesetwofirmschoosesitslevelofoutputsoastomaximizeprofitsontheassumptionthattheother’soutputisfixed.Calculateeachfirm’s“reactionfunction,”whichexpressesdesiredoutputofonefirmasafunctionoftheother’soutput.Ontheassumptioninpart(c),whatistheonlylevelforq1andq2withwhichbothfirmswillbesatisfied(whatq1,q2combinationsatisfiesbothreactioncurve)?Withq1andq2attheequilibriumlevelspecifiedinpart(d),whatwillbethemarketprice,theprofitsforeachfirm,andthetotalprofitsearned?Supposenowtherearenidenticalfirmsintheindustry.IfeachfirmadoptstheCournotstrategytowardallitsrivals,whatwillbetheprofit-maximizingoutputlevelforeachfirm?(Allthesewilldependonn.)Showthatwhennapproachesinfinity,theoutputlevels,marketpriceandprofitsapproachthosethatwould“prevail”inperfectcompetition.a.TR=PQ=(53-Q)QMR=53-由MR=MC即：53-2Q=5得：Q=24，p=b.AC1MC15AC2MC25TC15q1,TC2p1=(53-q1-q2)q1-5q1，p2=(53-q1-q2)q2-c.maxp1=(53-q1-q2)q1-482qq0q241q為企業(yè)1121221q241q為企業(yè)2212qcournot=q=12npi=(53-qi)qi-nn =53-q-q-5=>q=48-inpi=(53-qi)qi-nn =53-q-q-5=>q=48-iQnqn(48QQin,i=1,2,...,n，P=53-Q=5n+53p=pq-5qqii (nn4.Nicholson,Chapter19problem19.4Supposeafirm’scostsfordollarsspentonproductdifferentiation(oradvertising)activities(z)andquantity(q)canbewrittenasTC=g(q)+z,g￠(q)>andthatitsdemandfunctioncanbewrittenq=q(P,Showthatthefirm’sprofit-maximizingchoicesforPandzwillresultinspendingashareoftotalrevenuesonzgivenby=z.(ThisconditionwasderivedbyR.DorfmanandP.Steinerin“OptimalAdvert