E ± c iency G ainsfrom M ultilateralT rad e Agreem ents C »aglar OÄ z d en¤ E m ory U niversity A bstract Itis widely accepted thatthe G A T T regime has been quite e®ective in alleviating theproblemsfacedbytradeliberalizatione®ortsofthepast.T hereisnodoubtthatthe institutionalframeworkandtheG A T T principleshavebeenamongthemajorcausesof this success.U singageneralbargaininggameframeworkbetween governments acting intheirselfinterest,weshowthatmultilateralnegotiationsprovidetwodistinctsources ofe±ciencygains comparedtoanetworkofbilateralnegotiations.T hee±ciencygains ofmultilateralism arise from the ability (1 )to provide P areto superioroutcomes in marketwith largenumberofparticipants compared toseveralsmallerones and (2)to internalizetheexternalities imposed bydiscriminatoryarrangements on third parties. ¤ D epartment ofEconomics, Emory U niversity, A tlanta, G A 30 322. E-mail:cozden@ emory. edu. T his paperis based on chapter2 ofmy dissertation atStanford U niversity.I would like tothankA nneKrueger forencouragementand guidance,R obertStaiger, D ouglas B ernheim,A vnerG reif,P aulKrugman,R onald M cKinnon, Steven T adelis, P ravin Krishna, participants at the European Economic A ssociation A nnual Congress and departmentworkshops atStanford, Emory, Y ale, B rown, U niversity ofT exas atA ustin for comments and theO lin Foundation for¯nancialsupport.A llerrors aremine. 1 1 In trod uc tion T he period since the Sec ond nW orld W ar w itnessed a rapid lib eralizationofinternational trad e d uring w hic h the average tari® rate onnon-agric ulturalprod uc tsam ong ind ustrialized c ountriesd ropped f rom 4 5% to 4 % . T here islittle d ispute ab out the role played b y the num erousmultilateralround sofnegotiationsc ond uc ted at the auspic esofthe G eneral Agreem ent onT ari®sand T rad e (G AT T ).M ore rec ently, b ilateraland regionalagreem ents have b eengaining im portance interm softrad e polic y d eterm ination. Since m emb ership inthese negotiationf orum sisvoluntary, w hy d o c ountries¯nd it intheir self -interest to partic ipate insuc h regimesand ab id e b y their rules? W e are not the ¯rst onesto ask this question. O ne strand ofthe literature id enti¯ed the ine± c ienciesofunilaterally d eterm ined tari®s and the role ofthe trad e negotiationsinim plem entingP areto superior outc om es,espec ially inthe presence ofterm s-of -trad e m otivations.J ohnson's[1953/54 ] sem inalw ork isa m ain example ofthisliterature.T he m aininsight w e gainf rom these papersisthat inthe ab sence ofnegotiationsb etw eengovernm entsto low er their respec tive protec tionist m easures, the negative externalitiesc aused b y unilateralac tionsw illlead to P areto inf erior outc om es1. M ost ofthe papersthat estab lish the w elf are im provingpropertiesoflib eraliz atione®ortsd o not d istinguish b etw eend i®erent typesoftrad e agreem ents.T he analysisism ostly c arried out ina tw o-c ountry f ram ew ork and israrely extend ed to a multi-c ountry c ase,m ainly d ue to tec hnic ald i± c ulties.Another strand ofthe literature aim sto c om pare regionaland multilateralarrangem entsand triesto answ er w hether they are c om plem entsor sub stituteson the path to glob alf ree trad e2 How ever,the negotiationaspec t oftrad e polic y d eterm ination isignored and the f oc usisplac ed uponunilateralac tionsinb oth regional(c oalitional) and 1 T headjustmentprocesscanconvergetoaunique¯naloutcomeoratari®cycleneitherwhicharesocially e±cient. 2 U nfortunately, this question has turned outtobe very di±culttoformalize and asystematicanalysis has notyetemerged.T hestandardapproachhas beentocomparethewelfareproperties ofdi®erentregimes and theanswers seem todepend criticallyon theassumptions overtheunderlyingeconomicenvironment. 2 multilateralsettings. Inthispaper,our aim isto answ er the f ollow ingquestions:Canw e c om pare the w elf are implic ationsofmultilateraland b ilateral/regionalapproachesto trad e polic y f ormulation? Ifw e c an, isit also possib le to id entif y the sourc esofthe d i®erencesinresulting w elf are levels? T he answ er to the b oth questionsisyes.W e w illid entif y tw o d istinct sourc esofe± c iency gainsthat only multilateralnegotiationsc anprovid e w henc om pared to a netw orkof b ilateralnegotiations3.T hese e± c iency gainsresult f rom the f unctioningofany negotiation round (b ilateralor multilateral) asanexc hange m arket f or tari®sover w hich the ind ivid ual c ountries' payo®sare d e¯ned . Inthisf ram ew ork, the ¯rst sourc e ofe± c iency gainsarises f rom the ab ility to provid e superior outc om esina m arket w ith large numb er ofpartic ipants(c om pared to severalsm aller ones) through w elf are arb itrage ac rosspartic ipants.T his generalequilib rium result m anif estsitselfinthe f orm oftrad ing oftari® c oncessionsac ross c ountriesinthe G AT T negotiations.A sec ond sourc e ofe± c iencygainsarise f rom the ab ility to internaliz e the negative externalitiesim posed b yd isc rim inatoryarrangem ents.\M arkets" f or tari®sd i®er f rom other simple exc hange ec onom iesina signi¯c ant w ay since the tari® rate b etw eentw o c ountriesentersthe payo® f unctionofother c ountriesand thusc reates anexternality. For example, b ilateraltrad e lib eralizationb etw eenc ountry A and c ountry B w illnot only increase their w elf are levels, b ut it w illalso low er the w elf are ofc ountry C through the w ell-know ntrad e d iversione®ec t. M ultilateralnegotiationsprovid e P areto superior outc omesthrough the eliminationofthe negative externalitiesc aused b y d isc rim inatory arrangem ents(b etw eena group ofc ountries) onthird parties.Havingid enti¯ed the potentialw elf are gainsc reated b y multilateraltrad e b argaining, w e exam ine the rulesim plem ented inthe G AT T negotiationround s(rec iproc ity,unanim ity and non-d isc rim ination) to realize these gainsinthe next c hapter. M any papershave id enti¯ed the ine± c ienciesassoc iated w ith unilateralac tionsinthe 3 Inthenextchapter,wewillanalyzehowtheG A T T negotiationrounds werestructured and whatrules (reciprocity, unanimity and non-discrimination orthe M ostFavored N ation-M FN )were adopted torealize thee±ciencygains from multilateralism. 3 internationaltrad e literature, asw e stated earlier. E xtend ing J ohnson'sw ork onb ilateral trad e relationships,M ayer [1981] id enti¯ed the set ofP areto e± c ient tari® levelsand asked w hether ifc ertainG AT T lib eralizationrulesc anlead to the e± c ient points.Againinb ilateral f ram ew ork,R iezm an[19 82 ] asksifthe Nash b argaining solutionc anim plem ent ane± c ient outc ome4 . Ina series ofrec ent papers, B agw elland Staiger [19 96, 19 97a, b , c ] look at sim ilar issuesand f oc usonthe ine± c ienciesc aused b y term s-of -trad e and /or politic ally m otivated unilateralstrategies.InB agw elland Staiger [1996],they em phasiz e the P risoners'Dilem m a nature ofunilaterallyd etermined trad e polic iesw here term s-of -trad e m otivationsare present. T hisc reatesthe m otivationf or rec iproc allow eringoftrad e restric tionsina b ilateralsetting. T heyextend their analysisto a verystyliz ed multilateralsettingto see ifthere isany role f or non-d isc rim inationrulesinthe optim aloutc om e.How ever, they d o not set up anexam ple w here they c anexplic itly c om pare the w elf are c onsequencesofmultilateraland netw ork of b ilateralnegotiations.Inallofthese papers,their m ainc ontrib utionisem phasiz ingthe link b etw eenthe institutionalrulesofthe G AT T and ec onom ic e± c iency w hic h w e w illad d ress inm ore d etailinthe next c hapter. T here are variousstud iesanalyz ingc ertainad vantagesofmultilateralism inthe literature. B hagw ati [1990 , 1991a] m entionsthe d istrib utionalargum entsam ong the m ainb ene¯tsof multilateralnegotiations.Inmultilateralsettings,sm allc ountriesw illhave m ore b argaining pow er against b igc ountriesand w illb e ab le to im prove their w elf are.M aggi[19 96]show sthat multilateralism enhancese± c iencyd ue to increasesinenf orc em ent pow er ina repeated gam e setting.Since,there are unilateralincentivesto d eviate f rom agreed tari® levelsinany trad e agreem ent,a threat m ec hanism innec essary to d eter governm entsf rom cheating.O ne ofthe rolesofthe G AT T b ec om esto d issem inate inf orm ationand c oord inate punishm ents.Inthis paper,w e ignore enf orc ement issuesand assum e that allagreem entsare enf orc eab le.R ather, 4 A related question has been the enforcementofe±cientoutcomes. D ixit[1 987]and a series ofother papers identify the P risoners'D ilemma N ature of the trade negotiations and the role of the treaties in enforcinge±cientagreements. 4 w ef oc usonhow c ountriesac hieve a c ertainoutc om e.Asm entioned b yHoekm an[1993,199 6], ac hieving anoutc om e and enf orc ing it ina negotiationare c om plem entary issuesf ac ed b y polic y-makers.T heref ore M aggi'spaper and thispaper should b e seenasc om plem entssince they point out to d istinctive and c om plem entary gainsf rom multilateralism 5. K ow alcz yk and Sjostrom [19 94 ] analyz e the w elf are enhancingb ene¯tsofsid e paym entsinmultilateral negotiations,w hic h w e also ad d ressinthispaper. T hispaper hasstrongim plic ationsf or the regionalism vs.multilateralism d eb ate.T hese issueshave b eenonthe researc h agend a ofthe internationaltrad e ec onom istsf or d ec ad es and it isim possib le to sum m arize allofthe argum ents.Starting w ith Viner's[1950 ] trad e c reationvs.d iversiond istinctionand c ontinuing w ith K rugm an's[199 1a, 1991b ] in°uential trad ingb loc ksmod el,the stand ard approac h hasb eento f oc usonunilateralac tionsofagents inregionalor multilateralsettings.T he c ontroversialU -shaped relationship b etw eenw elf are and numb er oftrad ing b loc ksinthe K rugm anm od elsisthe result ofthe analysisb eing solely b ased onunilateralstrategies.How ever c ountriesengage innegotiationsto avoid the externalitiesc aused b y unilateraland c oalitionalpolic ies. W henthisob servationistaken into ac c ount,som e ofthe resultsare likely to change. T his paper d i®ers inone ¯nalrespec t f rom the previous papers since w e present all ofour resultsina very general(yet f orm al) b argainingf ram ew ork.E c onom ists' trad itional perc eptionofinternationaltrad e d ivergesf rom that ofpolic ym akersinim portant d im ensions. For ec onom ists,internationaltrad e isone ofthe m ost ob viousm echanism sto increase w elf are and the existence oftrad e b arriersisa typic alexam ple ofthe role ofpolitic sinec onom ic polic y-making(see G rossmanand Helpm an[199 4 ,19 95a,19 95b ]f or anextensive m od elthat introd uc esa politic altari® d eterm inationproc ess). Although there are m any theoretic al m od elsinw hic h trad e b arriersincrease w elf are, m ost ec onom istsstrongly b elieve that f ree trad e isthe b est polic y, evenifit isim plem ented unilaterally6.T heref ore there isno room 5 A ninterestingextension wouldbetoanalyzetheroleoftheG A T T principles,especiallytheM FN rule, intheenforcementmechanism. 6 See H elpman and Krugman (1 983)and H elpman (1 984)forextensive surveys ofthis in° uentialstrand 5 f or trad e negotiationsinthisperspec tive. O nthe other hand , governm ent o± c ialsw ho hand le the long and c umb ersom e negotiationshave d i®erent perc eptions. Aselec ted o± c ialsor b ureauc ratsappointed b y elec ted politic ians, their incentivesare in°uenced b y the interestsofthe ec onom ic ac torsintheir c ountry.T heref ore,it isim portant to ¯nd c om prom isesthat w ould m ake every governm ent b etter o® c om pared to the d ef ault optionsw ithinthe politic alc onstraints.T ari® negotiationsw orkasmec hanismsw here tari® c oncessions(or other protec tive m easuresthat impose externalitiesonthe trad ing partners) are exchanged such that the new outc om e im proves the w elf are ofallofthe governm entsw hich isb ased onpolitic alm otivations. Inad d ition to re°ec ting the f orm ationoftrad e polic iesina multilateralenvironm ent, the b argaining f ram ew ork explainsthe m erc antilist approach ofgovernm ents. (See K rugm an[199 1] f or a m od ernversionofmerc antilism.) T he next sec tionw illoutline the und erlying the generalequilib rium m od elw e w illb e using.T henw e w illestab lish the trad e polic yd eterm inationgam e asa b argaininggam e.T he e± c ient payo® f rontier w hic h w illf orm the m ainf oc usofanalysisinthe f ollow ingsec tionsw ill b e d e¯ned .Next, w e show the e± c iency gainsf rom multilateralism through c ross-c ountry trad es. T hen, the multilateralsetting w here b ilateraltreatiesim pose externalitiesonthe outsid er through trad e d iversionw illb e introd uc ed .U nd er these c irc um stances,there w illb e f urther P areto gainsto b e ob tained via multilateralnegotiationsthrough the internaliz ation ofthese externalities.T he c onclusionf ollow s. 2 T he B asic Setup T hissec tionw illintrod uc e a b enchm ark m od el. W e w illd e¯ne the d em and and supply f unctionsthat und erlie the nationalec onom iesand the governm ents' ob jec tive f unctions. Asymm etriesinthe supplyf unctions(d ue to end ow m entsofthe sec tor spec i¯c inputs) w illb e ofliterature. 6 the reasonsf or trad e b etw eenc ountries.T he strategiesavailab le to the governm entsc onsist oftari®sonthe im ports7 and w e w illd e¯ne the payo®softhe governm entsasf unctionsof the tari® rates. T he b enchm arkmod elissim ilar to the one used b yG rossm anand Helpm an[199 4 ].E ach c ountry ispopulated b y id entic alind ivid ualsw ho m axim ize a utility f unctiongivenb y uA = u(x0 ) + X i2H w here H A u(xi) A d enotesthe set ofgood sd em and ed inc ountry A and xi isthe c onsum ptionof good i.T hese ind ivid uald emand f unctionsare increasing,d i®erentiab le and c oncave.G ood 0 servesasthe numeraire w ith pric e set to 1:It ism anuf ac tured only w ith lab or using a c onstant returnsto sc ale prod uc tiontechnology w hich lead sto a w age rate of1 and the end ow m ent oflab or islarge enough to guarantee a positive supply ofgood 0 :Lab or and an inelastic ally-supplied sec tor-spec i¯c f ac tor are used inthe prod uc tionofthe other good s.T he prod uc tiontec hnology ofeac h good hasc onstant returnsto sc ale and d im inishing returns w ith respec t to lab or. T he mainad vantage ofthis f ram ew ork isthat the rew ard to the prod uc ersofany non-num eraire good and the c onsum er d em and f or it d epend only onits d om estic pric e w hile the numeraire good ab sorb sallofthe exc esssupply and d em and .T his generalequilib rium f ram ew ork w ith the resid ualnum eraire good isintend ed to rationalize the partialequilib rium approac h intrad e theoryand hasb eensuc c essf ullyused inG rossm an and Helpm an[199 4 ,199 5a,199 5b ]to explaintrad e polic yd eterm inationina politic alsetting. T hroughout the paper, w e w illassum e that there isonly one c ountry w ho im portsa good w hile one or m ore c ountriesm ight export it. W e w illnow f oc us ontw o good s, i and j; (w here i;j 6 = 0 ) that are trad ed b etw een 7 W e willassume thatexporttaxes and subsidies are notavailable.Exporttari®s are banned in many countries, including the U S, and subsidies are outlawed in G A T T (with fewexceptions forR &D and environmentalpurposes. ) H owever, the results ofthis paperwillnotchange as long as monetary transfers between the governmentand the ¯rms create deadweightlosses in the economy. Some examples are the costs incurredinthecollectionsystem oftaxes topayforthesubsidies andthedistortions oftari®s.A more detailed discussion ofexportpolicies is in thenextsection. 7 tw o c ountries, A and B . G ood i(j) isthe naturalexport good f or c ountry A (B ) d ue to end ow m entsofthe sec tor-spec i¯c f ac tors.Neither inor jisprod uc ed or d em and ed inany other c ountry.W e w illlet p xi d enote the pric e ofgood iinthe exporting c ountry, and p mi ; the pric e inthe importingc ountry.T he tari® levelis¿i w here ¿i = p mi ¡p xi (1) W e w illim pose no restric tionsonthe value of¿i inord er to allow im port sub sid ies.D (p) and S(p) w illd enote c ountry-w id e d em and and supply f unctions. For sim plic ity, w e w ill assum e that d em and and supply are linear and ,theref ore,the c onsum er surplus,© (p),and the prod uc er surplus, ¦ (p), are quad ratic inpric es8 .T he equilib rium pric esf or good iin b oth c ountriesw illb e d etermined b yequation(1) together w ith the f ollow ingm arket c learing c ond ition: D A (p xi) + DB (p mi ) = SA (p xi) + SB (p mi ) (2 ) W ith these tw o equations, w e c and eterm ine b oth export and im port pric esasf unctionsof the tari® leveland the exogenousend ow m entsofthe inputs.Sim ilar equationshold f or good j. Inc ountry A,the payo® d ue to the c onsum ptionofthe export good is UAx (¿i) = © A (p xi (¿i)) + ¦ A (p xi (¿i)) and the payo® f rom the im port good is ³ ´ ³ ´ n ³ ´ ³ ´o UAm (¿j) = © A p mj (¿j) + ® A¦ A p mj (¿j) + ¿j D A p mj (¿j) ¡SA p mj (¿j) 8 T helinearityassumptionis notnecessaryforanyoftheresults inthis paper.H owever,itmakes lifeand drawinggraphs much easier.Simple quasi-concavityassumption is su±cient. 8 w here the last term isthe tari® revenue9 ,10 and ® ¸ 1 d ue to lob b ying pow ersofimport c om peting ind ustries11 .Inthese d e¯nitions, the param eter ® isthe w eight attached b y the government to prod uc er surplusinthe im port sec tor w hic h isa stand ard w ay ofintrod uc ing politic alec onomy c oncernsofany governm ent into the analysis(see B ald w in[??],G rossm an and Helpm an[199 4 ,19 95,199 6]).It isstraightf orw ard to show that @U x @ 2 UAm @UAm @ 2 UAx j¿j< ¿jN > 0 ; A j¿i= 0 < 0 ; < 0 ; > 0 @¿j @¿i @¿j2 @¿i2 (3) G iventhese tw o f unctions,w e c and e¯ne the payo®sto each c ountry as12 ,13: UA (¿i;¿j) = UAm (¿j) + U Ax (¿i) UB (¿i;¿j) = UBm (¿i) + UBx (¿j) (4 ) Note that ¿j isa d ec isionvariab le f or c ountry A and ¿i f or c ountry B :T he task f ac ed b y the tw o governm ents is to d eterm ine the tari® levels, ¿i;¿j, giventheir respec tive payo® f unctions.W e w illref er to thisasthe tari® d eterm inationgam e. 9 D uring this paper, we willsustain the assumption thatthe directtransfers between governments are not allowed and some of the results depend on this assumption. H owever, this standard assumption in internationaltrademodels (seeD ixit[1 985])mightseem unjusti¯edtheoreticallysinceweallowtheobjective functions tobe linearin monetarypayo®s,i. e.tari®s.W e can stillmake theclaim thatunlimited transfers are notfeasible due topoliticalreasons.O rwe can modify the modelsuch thatthe governmentpayo®is aconcave function oftari®revenue due toine±ciencies in the domestictaxation and distribution systems which would preserve allofourresults. 10 W eshouldactuallydenotetheproducersurplusincountryA forgoodi as¦A ;i (px entgoods i )sincedi®er and countries willhave di®erentproduction functions.H owever,fornotationalsimplicity,we willsuppress the¯rstsubscript\ ¶ {". 11 In G rossman and H elpman [1 994], there is an ® ¸ 1 attached to the producersurplus in the payo® function ofthe exportsector. Since, we do notallow exportpolicies, there would be no lobbying e®orts (assumingtheowners ofthespeci¯cinputofxi areasmallportionofthepopulation)andwecanset® = 1 . N evertheless, the qualitative nature ofthe results would notchange ifthe weights were di®erentin each payo®function. 12 A ctually,U m (:)is strictly concave and U x(:)is strictly convex because ofthe linearity assumption on theunderlyingdemand and supplyfunction. 13 N ¿j is unilateralN ash tari®levelde¯ned inthenextparagraph. 9 3 B argain ingFram ew ork W e now f ormulate the tw o-c ountry tari® d eterm inationgam e asa b argaining gam e. T he f orm ald e¯nitionofthe b argainingprob lem ,asgivenb yO sb orne and R ub instein(199 0 ),c an b e stated asthe f ollow ing: De¯n ition :A bargainingproblem isd e¯ned asthe pair (S;d ) w here S½R +2 isc om pac t and c onvex,d 2 S,and there existssom e s 2 S such that si > d i f or alli= 1;2 . Inthissetting,S isthe f easib le payo® set,d isthe d isagreem ent point and s isany point w hic h im provesupond f or allplayers.T he d isagreem ent point w illb e givenb y the unilaterally d eterm ined tari®sthat result inthe (unique) Nash E quilib rium ofthe simultaneous m ove tari® setting game w here payo®sare givenb y equation(4 ). T hese unilateralNash tari®sw illb e d enoted as¿jN and ¿iN and they are d eterm ined b y simultaneously solving: ³ ´ ¿jN = argm¿axUA ¿iN ;¿j j ³ ¿iN = argm¿axUB ¿i;¿jN i ´ G ivenc ond itionsin(3) and quad ratic payo® f unctions,the Nash tari® levelsw illb e positive and unique.T he payo®sc orrespond ingto the unilateraltari®s,d enoted asUAN and UBN ,w ill b e the low est levelsthat w e assum e w illoc c ur inthisenvironm ent.T he tari® settinggam e, w henplayed unilaterally asa single stage gam e w ithout b argaining, w illhave the nature ofa P risoner'sDilem m a game14 .T he f easib le P areto superior outc om esare not supported b y a Nash E quilib rium ina single stage, static gam e15. W e b elieve that one ofthe m ost 14 T heP risoners'D ilemmanatureofthetari®settinggamehasbeennotedbymanyauthorsintheliterature and is the main motivation fortheuse ofrepeated game techniques toavoid P aretoinferiorequilibria.See D ixit[1 987]fordiscusssion. 15 H owever,theseequilibriacan besupportedinarepeated settingthroughtriggerstrategies as shownby various FolkT heorems.T hese theorems areexistenceresults and in mostcases pointtoan in¯nite number ofequilibria. 10 important rolesoftrad e negotiationsisto id entif y the set ofP areto Superior outc om esand selec t anelement ofthisset asthe equilib rium . T he next step isto d e¯ne the P areto Superior set S. InF igure 1, the c urvesUAN and UBN represent the pairsoftari® levelsat w hich each c ountry hasthe sam e levelofpayo® as the one attained w ith the Nash tari® levels.T his¯gure im pliesthat any pair oftari® levels insid e the tw o c urvesimprovesw elf are f or b oth c ountries.Inthissetting,a trad e agreem ent w illb e e± c ient if " # d ¿i d ¿j = d U A= 0 " # d ¿i d ¿j (5) d UB = 0 or sim ply w hentw o ind i®erence c urvesare tangent to eac h other inthe tari® spac e.Since h i d ¿i d ¿j d U = 0 A = 0 and h i d ¿i d ¿j d U = 0 B ³ ´ = 1 at ¿iN ;¿jN ; the unilateralNash tari® levelsare not e± c ient and there existsopportunitiesf or P areto im provem ents16.Inother w ord s,the set S isnot em pty. T he f easib le and e± c ient f rontier c analso b e c harac teriz ed asthe set ofpoints(UA;UB ): 8 9 > > > < (UA;UB ) :UA = max U A (¿i;¿j) + ¸ [ UB (¿i;¿j) ¡UB ]; > = > > : ¿i;¿j;¸ UA ¸UAN (6) > > ; ;UB ¸UBN w here ¸ is the Lagrange multiplier. W e c ansim ply d e¯ne the e± c ient f rontier w ith the equationUA = f (UB )17:T he tari® pairs (¿i;¿j) that solve the c onstrained optim iz ation prob lem f or a givenUB ind e¯nition(6) w illsatisf y equation(5).W e now c harac teriz e the f unctionUA = f (UB ): ³ ´ T he ind i®erence c urvesc orrespond ingto UAm ax = f UBN and UAN = f (U Bm ax) inthe tari® spac e are d raw ninF igure 2 .Am ax and B m ax are respec tively the pointsat w hic h c ountry A and c ountry B attaintheir maximum payo®s18 . 16 W eborrowedthis notationforthede¯nition ofe±ciencybyB agwellandStaiger[1 996] . 17 W ealsohavethe restrictions U A ¸U AN and U B ¸U BN on the function. 18 T he e±cienttari®locus (orsimplythe contractcurve)is the dotted line between A max and B its properties willbeestablished later. 11 max and T he ¯rst ob servationisthat the e± c ient payo® f rontier,UA = f (UB ) isstric tlyd ow nw ard sloping and stric tly c oncave. T hisisa d irec t c onsequence ofthe envelope theorem w here f0(UB ) = ¡¸ < 0 (f or UB < UBm ax) and the d i®erentiationofthe ¯rst ord er c ond ition f00(UB ) = ¡d dU¸B · 0 . W ith the shape ofthe e± c ient payo® f rontier estab lished , w e c an state the f ollow ing: P rop osition1 : T he tari® settinggam e betw eentw o countries is a stand ard B argaining P roblem, asd e¯ ned above. P roof :T he proofisstraightf orw ard . W e have d e¯ned the d isagreem ent point and existence ofP areto superior outc om es.T he e± c ient payo® f rontier, UA = f (UB ), d e¯nesthe b ound ary ofthe payo® set over w hich the governm entsw illb argain. Since it isc oncave, d ow nw ard slopingand d e¯ned over UBN ·UB ·UBm ax, the f easib le set S isc losed ,b ound ed and c onvex.Q. E .D. T he e± c ient payo® f rontier w ith the d ef ault (unilateralNash) outc om esd e¯nesour b argaininggam e.E ± c iency inanyb argaininggam e requiresthat the outc om e isloc ated onthe b ound ary ofthe f easib le set w hic h isgivenb y the e± c ient payo® f rontier,(UA;U B ):It isno c oincid ence that e± c iency inthe trad e-theoretic sense and b argainingsense are equivalent. T hisequivalence isac tually the reasonthat enab lesusto treat the trad e negotiationgam e asa stand ard b argaininggam e. Another f unctionto b e d e¯ned isthe e± c ient contrac t c urve (¿i;¿j) w hich isthe d otted line b etw eenAm ax and B m ax inF igure 2 . T he f ollow ing propositionestab lishesitsm ain properties. P rop osition2 : T he e± c ient contrac t c urve inthe tari® space is stric tly concave and d ow nw ard sloping. P roof : See the append ix 12 T his propositionim plies that w e c and enote the e± c ient c ontrac t c urve as a f unction¿i = g (¿j). Also, w e c anestab lish a very im portant relationship b etw eenthe pairs (f (UB );UB ) and (g (¿j);¿j):Since b oth are nic ely b ehavingf unctions,there isa one-to-one c orrespond ence b etw eenthem .Asw e m ove alongthe graph of(g (¿j);¿j) inthe tari® spac e, ¿j (¿i) ism onotonic ally increasing (d ec reasing) w hich im pliesUA (UB ) isstric tly increasing (d ec reasing).Since f (:) isd ow nw ard sloping,increasinga c ountry'spayo® requiresd ec reasingthe other'spayo®.Inord er to increase (d ec rease) c ountry A'spayo®,the tari® charged onher im portsmust increase (d ec rease) and the tari® charged to her exportsmust d ec rease (increase) simultaneously alongthe e± c ient payo® f rontier.For c om pleteness,w e w illm ake the f ollow ingd e¯nitionsw hic h w illb e used inthe rest ofthe paper: De¯n ition :Ane± c ient outcome ofthe tari® settinggam e (and the equivalent b argaining prob lem) isa tari® pair (¿i;¿j) w hic h isonthe e± c ient c ontrac t c urve (g (¿j);¿j)and w hich lead sto payo® levels (U A;UB ) that are onthe e± c ient payo® f rontier (f (UB );UB ). An e± c ient bargainingprocesslead sto a unique e± c ient outc om e. T hisd e¯nition(or thissec tion) d oesnot m ake any pred ic tionsab out the outc om e ofthe b argaininggam e.How ever,the c laim isthat a m ore f avorab le outc om e f or a c ountry im plies a monotonic d ec rease inthe tari®sf ac ed b y her exportsand m onotonic increase inthe tari® employed tow ard sher imports. So, ifw e ob serve tw o c ountriesmutually d ec reasing their tari® levelsc om pared to a previousagreem ent, w e c anc onclud e that either (1) they w ere previouslynot onthe e± c iencyf rontier or (2 ) som e exogenousparam eter,suc h aspref erences or end ow m ents,shif ted the e± c iency f rontier.T hisone-to-one c orrespond ence b etw eenthe payo® levels and the tari®s m akes the f ollow ing analysis very easy since it im plies that b argainingover tari®s(w hic h w e see inG AT T negotiations) isequivalent to b argainingover payo®s(w hic h w e see inthe theoretic alb argainingm od els).For the rest ofthe paper,w e w ill f oc usonthe e± c ient payo® f rontier d e¯ned b y the f unctionf (UB ) w hich im plic itly d epend s onexogenousparam eters.O nce w e choose a spec i¯c point onthisf rontier, w e c ango b ack and d eterm ine the e± c ient tari® levelsthat lead to that payo® pair. 13 T he mainresultsofthissec tionare that (1) unilateralNash polic iesare ine± c ient and (2 ) trad e agreements(w hether they are b ilateralor m ultilateral) play a unique role inreaching e± c ient tari® levels. T his point is not new and has b eenm entioned repeated ly inthe literature.T he im plied rec iproc ity inthisproc essisone ofthe m aininsightsofthe B agw ell and Staiger [1996] paper, asw e m entioned b ef ore. How ever, asc anb e seeninF igure 3, there are anin¯nite numb er ofe± c ient trad e agreem entsavailab le to the c ountriesand they c aneasily b e P areto ranked f rom each governm ent'sperspec tive.T hus, the sec ond role of the trad e negotiations(other thanreac hingane± c ient tari® level) b ec om esto d eterm ine at w hic h e± c ient tari® levelthe playersw illend up. 3. 1 Sid e Note onthe R ol e ofE xport P ol ic ies E xport taxesand sub sid iesare not availab le aspolic ytoolsto the governm entsinthismod el. T hisassum ptionw asb ased onthe lac kofw id espread use ofthese polic iesb ythe governments and the G AT T polic iesinthisregard .A m ore c om plete m od elw ould d erive thisob servation asanequilib rium outc om e b ut thisisb eyond the sc ope ofthispaper19 .How ever,the ab sence ofthe export polic ieshasstrong im plic ationsf or the m od elw hic h need to b e ad d ressed at thispoint. T he simultaneouspresence ofexport and im port polic iesenab lesgovernm entsto set the w orld pric e that maxim iz e their joint w elf are and use their respec tive polic iesto transf er w elf are f rom eac h other2 0 . Inother w ord s, the prob lem sim pli¯es to solving the w orld pric e that m aximiz esthe joint w elf are ofthe tw o governm ents,takingthe politic alec onomy d istortionsinto ac c ount. Inthe b argaining prob lem , the e± c ient payo® f rontier b ec om es linear (instead ofthe stric tly c oncave shape w e have) and c ountriesnegotiate over a ¯xed pie. Inother w ord s, the availab ility ofexport polic iesalongsid e im port polic iesb ec om es 19 See R odrik[1 995]foradetailed explanation on why the e±cientpolicy tools mightnotbe used in the equilibrium ofagame where thechoice ofthepolicytoolis alsoendogenous. . 20 Inthefollowingpapers [1 996,1 997b],B agwellandStaigertakeadvantageofthis propertyand focus on thenettari®s instead oftheactualtari®s. 14 equivalent to havinga c ostlesstransf er m echanism .T he ab sence ofexport polic ies,theref ore, hasnegative w elf are im plic ationssince m ost outc om esw illim ply glob alw elf are lossesf rom the governm ents'perspec tive and shrinkingofthe f easib le payo® set.T he sam e result w ould b e ob tained ina generalequilib rium setting w ith tw o good sand only im port polic iesd ue to the Lerner symm etry theorem .Inthe f ollow ing sec tions, w e w illshow that multilateral b argaining b ec omesevenm ore im portant b ec ause ofthe unavailab ility ofexport polic ies. Nevertheless, f urther researc h isneed ed to point out other c osts ofim plem enting export polic iesthat outw eigh the ab ove m entioned e± c iency b ene¯ts. 4 M ul tic oun try Negotiations O ne ofthe d e¯ningc harac teristic softhe past G AT T negotiationround sistheir multilateralism.Ineac h round ,more c ountriesnegotiated over m ore issuesf or longer period softim e. M any ec onom istsand polic ymakersc laim that the multilateralnature ofthe trad e negotiationsc ontrib uted to the suc c essinred uc ingtari® levelsand increasingw elf are f or allofthe m emb er c ountriesinthe last ¯f ty years. W e w illtry to show the theoretic alf ound ations ofthisob servations¯rst through a three c ountry c ase. T he c laim w illb e that w elf are in trilateralnegotiationishigher thanthe settingw ith three b ilateralnegotiations. T he b asic b uild ingb loc ksofthe m od elw illb e sim ilar to the onesinthe previoussec tion. T here are three c ountriesand six good s. Any pair ofc ountriestrad e tw o d istinct good s w hic h are neither c onsumed or prod uc ed inthe third c ountry and , theref ore, none ofthe b ilateralnegotiations im pose externalitiesonthe outsid ers. fab (UB ) d e¯nesthe e± c ient payo® f rontier ofthe b ilateralb argaininggam e b etw eenc ountryA and B :fab (UB ) isc oncave and d ow nw ard sloping. fac(UC ) and fbc(UC ) are sim ilarly d e¯ned f or the gam esb etw een A & C and B & C respec tively. T he e± c ient payo® f rontier f or the trilateralb argaining 15 c onsistsofthe points(UA;UB ;UC ) and w illb e charac terized asthe f ollow ing: 8 > > > > > < (UA;UB ;UC ) :UA = m axUA (¿ab;¿ba ) + UA (¿ac;¿ca) + ¸ B [ UB (¿ab;¿ba ) + U B (¿cb;¿bc) ¡UB ]+ ¸ C [ UC (¿ac;¿ca) + UC (¿cb;¿bc) ¡UC ]; > > > > > : UA ¸UAN ;U B ¸UBN ;UC ¸UCN 9 > > > > > = > > > > > ; (7) w here ¿ab isthe tari® im posed b y c ountry A onc ountry B :Sim ilarly, w e c and e¯ne this e± c iency f rontier ofthe f easib le payo® set w ith the equationUA = F (UB ;UC ) w ith the c ond itionsthat UA ¸UAN ;UB ¸U BN and UC ¸UCN :T he d e¯nitionofthe B argaining gam e c anb e easily extend ed to the three c ountry c ase w ith d = ofS isd e¯ned b y the f unctionUA = F (U B ;UC ). ³ UAN ;UBN ;UCN ´ and the b ound ary ³ ´ ³ ´ Suppose the b ilateralb argaininggam e outc om e b etw eenc ountry A and B is UAab;UBab ³ ´ w here UAab = fab UBab :T hisoutc om e isuniquely d eterm ined asa result ofa b argaining game d esc rib ed inthe previoussec tion.Again,w e sim ilarly d e¯ne (UAac;U Cac) and UBbc;U Cbc ¤ ¤ asoutc omesofthe other tw o b argaininggam es.W e w illlet (¿ab ;¿ba ;::) d enote the tari® levels ofthese b ilateraloutc om esand w illlet UA¤ = U Aab + UAac; UB¤ = UBab + UBbc;UC¤ = UCbc+ UCacb e the totalpayo®s.T he f ollow ing propositionw illhighlight the m ainb ene¯t ofmultilateral b argaininggame d espite the f ac t that the ind ivid ualb ilateralgam esare ind epend ent ofeach other. P rop osition3 :T here isa point onthe e± c ient payo® frontier oftri-lateralbargainingthat P areto d om inatesany outcome ofthe netw orkof(three ind epend ent) bilateralnegotiations. P roof : See the append ix. T his propositionsaysthat the outc om e ofthe netw ork ofb ilateralb argaining gam es m ight not b e onthe e± c iency f rontier ofthe trilateralgam e and ,theref ore,P areto superior outc omesw illb e availab le ina multilateralgam e2 1 .T hisresult isid entic alto the e± c iency 21 M aggi [1 996]has asimilarresultwhich shows in aN ash B argainingframework,multilateralbargaining providesP aretosuperioroutcomescomparedtoanetworkofbilateralgamesonlywhenthereareasymmetries acrosscountries.O urresultismuchmoregeneralandshowsthatgivenanyenvironmentunderanybargaining framework,foranybilateraloutcome thereis aP aretosuperiormultilateralone. 16 requirementsina generalequilib rium ec onomy w ith exchange.E ± c iency requiresthat, at the optimum,everyb od y'srelative m arginalvaluationsofany tw o good sthat they c onsum e (the tari® ratesinthisc ase) are equal.At the sam e tim e,there are no triangular arb itrage opportunitiesso d UA d UA = d UC d UB = d UB d UC issatis¯ed . Ifthislast requirem ent d oesnot hold , then there are opportunitiesf or \b arter"ac rossgovernm ents(or triangular arb itrage),and w elf are improvem entsf or allgovernm entsare possib le.Since there are no assum ptionsinherent in the b argaininggame that guarantee thisthrough the b ilateralnegotiations,w e w ill(almost) alw aysb e b etter o® (and never w orse o® ) c ond uc tingmultilateralnegotiationsto realiz e all e± c iency gains. T hisresult m ight seem surprising at ¯rst, since none ofthe b ilateralb argaining gam es e®ec t any other governmentsand the tw o tari® ratesthat tw o governm entsare negotiating over d o not enter the payo® f unctionsofother governm entsd ue to the very strong ind epend ence assum ptionw e m ad e.E venthough governm entsc annot im prove their payo®sin eac h b ilateralgam e (since they are onthe e± c iency f rontier),trilateralb argainingprovid es f urther opportunities.T histype oftrad ing ac rossc ountriesisextensive d uring the G AT T negotiationsasd oc um ented b y m any authorssuch asHoekm an[19 95].Anextrem e exam ple w ould b e the c ase w here A only importsf rom B w ho only im portsf rom C w ho only im ports f rom A.Inthisc ase,b ilateralnegotiationsw illnot b ringany trad e lib eraliz ationsince none ofthe c ountrieshasanythingto o®er f or their im porter (they have nothingto exc hange f or the good theyw ant) .How ever,through trilateralnegotiations,it ispossib le to ac hieve low er tari®sand w elf are gains2 2 . Anim portant extensionofthispropositionw ould b e to the \N "c ountry c ase.Suppose that N ¡1 c ountriesnegotiate multilaterally and reac h a point ontheir joint e± c ient payo® 22 A s A vnerG reifpointed out,ifA andB couldsignabilateralcontractover¿ab and¿ba thatestablished thesetari®rates as functions oftheoutcomes oftheotherbilateralagreements (ratherthansinglenumbers), thenthise±ciencygainsfrom multilateralism couldbecapturedthroughbilateralnegotiations.H owever,this conditionalbilateralnegotiationframeworkis exactlyhowmostofthemultilateralnegotiations arehandled! T hus,themain di®erencebetweenmultilateralandbilateralnegotiations (in theabsenceofexternalities)is theabilitytowrite conditionalcontracts.I would liketothankA vnerforthis clari¯cation. 17 f rontier,thusexploit allpossib ilitiesofw elf are im provem ent.Also,allofthem have b ilateral relationshipsw ith anN th c ountry. Now , thisc ountry w antsto jointhe multilateraltrad e negotiations.T he f ollow ingpropositionestab lishesthe w elf are c onsequencesofthisac tion. Corol l ary 4 : T he entry ofa new governm ent to anexistingm ultilateralnegotiationw ill result inP areto gainsfor allcountries. P roof : See the append ix T hispropositionstatesthat the totaland ind ivid ualw elf aresare increasinginthe numb er ofgovernm entspartic ipatinginthe negotiations.W henm ore governm entsare present,there w illb e m ore opportunitiesf or trad e ac rossc ountries. F inally, the f ollow ing c orollary isa d irec t implic ationofthe ab ove result. Corol l ary 5 : T he highest payo® w illbe realized w henallgovernm entsnegotiate jointly. P roof : It f ollow sd irec tly f rom the ab ove result. Asexpec ted , multilateralb argaining w ith the highest numb er ofpartic ipantsm axim ize ind ivid ualand totalw elf are. T his sec tionid enti¯ed w hy w e see trad ing ofissues ac ross c ountriesand how thisa®ec tsw elf are ofthe partic ipants.T hissim ple setting allow susto ob serve the propertiesofmultilateralnegotiationsthat increase w elf are.O ne im plic ationof the ab ove resultsisthat trad e polic iesw illb e renegotiated once a new m emb er joinsthe group since it w illb ring more opportunitiesf or trad e, (evenb etw eenthe old m emb ers) and the e± c ient payo® f rontier w illshif t out.T he ever-c ontinuingnature ofthe G AT T negotiations m ight b e partly d ue to thisreason; c ountries renegotiate trad e polic ies(m ostly d ec rease trad e b arriers) to take ad vantage ofnew entries.Another im plic ationisthat c ountriesw ill m ove tow ard sf ree trad e outc om e asm ore c ountriesjoin.Alltari® levelsw illnot d ec rease b ut the generalm ovem ent w illb e inthat d irec tionto estab lish higher payo®s. 18 4. 1 E xport P ol ic ies,O n c e Again P reviously,w e had mentioned that the presence ofexport polic iesisequivalent to the transf orm ationofthe e± c ient payo® f rontier to a linear f orm , c om pared to itsstric tly c oncave shape. W henthisf rontier islinear, w e w illhave d UA d UB = 1f or allb ilateralnegotiationsf or alle± c ient outc om es.T hisimpliesthere w illb e no opportunitiesf or \triangular arb itrage" b etw eenc ountriesand no c ross-c ountry exchanges.T here w illb e no reasonto hold multilateralnegotiationssince there w illb e no possib le P areto gains.Inother w ord s,the ab sence ofexport polic iesb ec omesone ofthe m ost im portant reasonsf or hold ingmultilateraltalks. How ever,the next sec tionw illpoint out f urther b ene¯tsofmultilateralism . 5 M ul tic oun try Negotiationsw ith E xternal ities So f ar, w e assum ed that the trad e relationship b etw eentw o c ountriesd id not d irec tly af f ec t the w elf are ofany other c ountry.T hisind epend ence, though it sim pli¯ed the analysis c onsid erab ly, isf ar f rom reality inm od erntrad e relationships.Any trad e c reatingb ilateral agreem ent b etw eentw o c ountriesw illhave im plic ationsonother c ountriesthrough trad e d iversione®ec ts(that are m ost likely to b e negative externalities.) Inthissec tion, w e w ill argue that the other mainreasonf or hold ingm ultilateraltrad e negotiationsisto internalize these externalitiesthrough the b argainingproc essand provid e f urther e± c iency gains. T o analyz e thissourc e ofe± c iency,w e w illuse a stylized three c ountryc ase w hose results c anb e easily generalized to the N ¡c ountry c ase. F irst, inthissec tion, f or sim plic ity, w e w illassume that ® A = ® B = ® C = 1 so the governm entsaim to m axim iz e the soc ialsurplus w ith no politic almotivations.T here are three good sw hich are d enoted b y a;b and c .G ood a isprod uc ed b y c ountriesB and C and c onsum ed b y only c ountry A:T he end ow m entsof the sec tor-spec i¯c f ac tor f or good a are id entic alinc ountriesB and C ; thusthe supply and prod uc er surplusf unctionsare id entic al.T he sam e setup appliesto good sb and c :T heref ore, inequilib rium ,c ountryA im portsgood a f rom one or b oth ofthe other c ountriesand exports 19 good b to c ountry B and good cto c ountry C : W e w illlet ¿ab b e the tari® rate im posed b y c ountry A onc ountry B . Anequilib rium involvesthe d eterminationofsix such tari® ratesb etw eenthree c ountries. T he payo® f or c ountry A isthe sum ofthe payo®sf rom tw o export sec torsand anim port sec tor. T he export sec tor payo®sf or good sb and c , d enoted asU X (¿ba ;¿bc) and U X (¿ca;¿cb), are the sum s ofc onsumer surplusand the prod uc er surplus. T he im port sec tor payo®, d enoted as U M (¿ab;¿ac), is c omprised ofc onsum er surplus, prod uc er surplus and tari® revenues. W henthe supply and d em and f unctionsare linear, the payo® f unctionsd e¯ned ab ove w ill b e quad ratic intheir param eters.Also,b ec ause ofthe sym m etric struc ture ofthe m od el,the f unctionsw illb e symm etric intheir param etersasw ell. T hus, the overallpayo® f unction f or c ountry A isgivenb y U A (¿ab;¿ac;¿ba ;¿bc;¿ca;¿cb) = U M (¿ab;¿ac) + U X (¿ba ;¿bc) + U X (¿ca;¿cb) (8) W e c and e¯ne the ob jec tive f unctionsf or the c ountriesina sim ilar w ay.(¿ab;¿ac) are d ec ision variab lesf or c ountry A,(¿ba ;¿bc) f or c ountry B and (¿ca;¿cb) f or c ountry C . It isstraightf orw ard to show that the unilateralNash tari® ratesim posed b y a c ountry tow ard sthe trad ing partnersw illb e equal,satisf yingthe M F N requirem ent.How ever, this isd ue to the very strong sym metric nature ofthe m od el.Sim ilar to previoussec tions, the Nash tari® ratesare ine± c ient and there are P areto gainsto b e achieved through rec iproc al low eringoftari® rates.Still,there isno reasonto assum e that the resultingtari® ratesw ill satisf y the M F N c riteria w henthe c ountriesengage intrad e negotiationsto im prove their w elf are .T o c om pare the implic ationsofthe M F N requirem ent w hich isof tenob served in multilateraltrad e agreem ents,w e w illanalyz e severald i®erent regim es.T he ¯rst one isthe m ost generalc ase w here there are no restric tionsonthe tari® rate.Asinthe previousc ase, 20 the P areto f rontier c onsistsofthe points(UA;UB ;U C ) such that 8 > > (UA;U B ;UC ) :UA = m axUA (¿ab;¿ac;¿ba ;¿bc;¿ca ;¿cb) > > > > > > < > > > > > > > > : + ¸ B [UB (¿ab;¿ac;¿ba ;¿bc;¿ca;¿cb) ¡UB ] + ¸ C [UC (¿ab;¿ac;¿ba ;¿bc;¿ca;¿cb) ¡U C ]; UA ¸UAN ;UB ¸U BN ;UC ¸UCN 9 > > > > > > > > = > > > > > > > > ; (9) T hen,w e c anw rite the P areto f rontier asa f unctionUA = F G en (UB ;UC ) w here w e have the requirement that UA ¸UAN ; UB ¸UBN ,UC ¸UCN :T he P areto e± c ient f rontier inthisregim e hasthe similar propertiesofthe previoussec tion.T he f rontier isc oncave and increasingin one d imensionrequiresd ec reasesinthe other tw o d im ensions;thusthe f easib le set isc onvex. T he sec ond regim e isthe w eb of(three) b ilateralnegotiationsb etw eenthe three c ountries. Ineac h b ilateralnegotiation, the partiestake the outc om esofthe other (tw o) negotiationsasgivenand reac h a pair ofe± c ient tari® rates. For exam ple, ifA and B are negotiating over (¿ab;¿ba ), the e± c ient outc om e w illb e a f unctionofthe other f our tari® rates. T he equilib rium point ofthisnetw ork ofb ilateralnegotiationsw illb e a vec tor of tari®s¿ B = ³ ´ B B B B B B ¿ab ;¿ac ;¿ba ;¿bc ;¿c uch that they solve the f ollow ing system ofequations a ;¿c b s simultaneously: 8 ³ ´ h ³ ´i® h ³ ´i1¡® > B B B B B B B B B B > > ¿ ;¿ = argm ax U ¿ ;¿ ;¿ ;¿ ;¿ ;¿ U ¿ ;¿ ;¿ ;¿ ;¿ ;¿ A ab ba B ab ba > ab ba ac bc c a c b ac bc c a c b > < ³ ´ h ³ ´i¯ h ³ ´i1¡¯ B B B B B B B B B B ¿ac ;¿c ;¿ca;¿ab ;¿ba ;¿bc ;¿c U C ¿ac;¿ca ;¿ab ;¿ba ;¿bc ;¿c a = argm ax U A ¿ac b b > > ³ ´ h ³ ´i°h ³ ´i1¡° > > > B B B B : ¿ B ;¿ B = argm ax UB ¿bc;¿cb;¿ B ;¿ B ;¿ B ;¿ B U ¿ ;¿ ;¿ ;¿ ;¿ ;¿ C bc c b bc c b ab ba ac c a ab ba ac c a 9 > > > > > = > > > > > ; (10 ) f or some ® ;¯ ;°(w here 0 > ® > 1;0 > ¯ > 1;0 > °> 1)2 3. T hese param eterslead to ane± c ient outc ome ineac h ind ivid ualb argaining gam e giventhe outc om esofthe other b argaininggam es.Depend ingonthe und erlyingpayo® f unctions,there c anb e multiple set ofsolutionsf or thisset ofequationsor no solutionsat all.For the rest ofthe paper w e w ill assum e that at least one equilib rium exists.At the equilib rium point, no pair ofc ountries 23 W e assume thatthese inequalities are stricttoavoid some technicalproblems.T hey donote®ectthe results inanyway,butsomeproofs would becomemoreelaborate. 21 w illhave the incentive to renegotiate their b ilateraloutc om e since they w ould b e alread y on the (b ilateral) e± c iency f rontier.T he f ollow ingpropositionestab lishesthe glob ale± c iency propertiesofthe equilib rium pointsinsuc h a netw ork ofb ilateralnegotiations: P rop osition6 : No equilibrium outcom e ofthe netw ork ofbilateralnegotiations w illbe globally P areto e± c ient.Inother w ord s, no solutionto the equations(10 ) w illbe inthe set givenby (9). P roof :See the append ix. Inthe previoussec tionw here the b ilateraltrad e relationshipsd id not im pose externalities onthe third c ountry, it w as possib le, b ut not guaranteed , that the netw ork ofb ilateral negotiationsc ould implement a glob ally e± c ient outc om e.Inthisc ase, w here the b ilateral treatiesc reate trad e d iversione®ec ts,thisno longer ispossib le.A netw orkofb ilateraltreaties never im plem entsa glob allye± c ient outc om e and thisb ec om esthe other m ainm otivationf or hold ing multilateralnegotiations.E ac h b ilateralnegotiationim posesnegative externalities onthe outsid e c ountry and there existsa m ultilateraloutc om e that isP areto superior to any b ilateralnetw ork outc ome. T he ab ove result d oesnot require the tari®sim posed b y A onB and C (¿ab;¿ac) to b e equalto each other,inother w ord s,d isc rim inatorytari®sare allow ed .How ever,one c om m on f eature ofmultilateraltrad e agreementsisthe non-d isc rim inationor the M ost Favored Nation (M F N) c lause w hic h memb er c ountriesf rom im posingd i®erent tari®sonid entic alprod uc ts c om ingf rom tw o d i®erent sourc es.Ina m athem atic alsense,these are f urther c onstraintson the P areto f rontier given(9).T he new P areto f rontier ofthe multilateralb argainingsetting w ith the M F N requirem ent w illb e givenb y the f ollow ingset ofpoints: 8 > > > > > < (UA;UB ;UC ) :UA = m axUA (¿a ;¿b;¿c) + ¸ B [ UB (¿a ;¿b;¿c) ¡UB ]+ ¸ C [U C (¿a ;¿b;¿c) ¡UC ]; > > > > > : UA ¸UAN ;UB ¸U BN ;UC ¸UCN 22 9 > > > > > = > > > > > ; w here ¿a isthe tari® im posed b y c ountry A onher im portsregard lessoforigin.UA (¿a ;¿b;¿c) c anb e ob tained f rom equation(8) w ith the appropriate sub stitutions.W e w illd enote this P areto f rontier asUA = F M FN (U B ;UC ). T hisf rontier hasthe sam e propertiesasU A = F G en (UB ;UC ) w hic h c anb e show nusing the sam e argum entsinthe previousproposition. O ur ¯rst aim isto c om pare these f easib le setscharac teriz ed b y the P areto f rontiers: P rop osition7 T he feasible set ofthe M F N m ultilateralbargainingisa subset ofthe feasible set ofthe generalbargaining.Inother w ord s, the m ultilateralnegotiationsw ith no restric tions P areto d om inatesthe M F N negotiations. P roof : See the append ix. T he propositionshow sthat f or any e± c ient M F N tari® c on¯guration, there isa nonM F N one that P areto d ominates it. Sim ply put, the M F N requirem ent inmultilateral trad e negotiationsc reatese± c iency losseseveninthisextrem ely sym m etric m od el. T his result isnot surprisingsince introd uc tionofad d ed c onstraintsw illalw aysresult ina sm aller f easib le setsand the M F N requirement sim plyim posesextra c onstraintsonthe optim iz ation prob lem.Ina b argaining sense, im positionofthe M F N rule d istortsthe e± c ient exchange ofc oncessions.T he result ofthispropositionc anb e seeninF igure 5 w here higher (low er) surf ac e c orrespond sto the e± c ient payo® f rontier ofthe general(M F N) negotiations.T he tw o surf ac esintersec t at one point w hich c orrespond sto the f ree trad e payo®s.G iventhis lossofe± c iency d ue to the M F N rule, it isim portant to know w hy it issuch anintegral part ofmultilateraltrad e agreem ents.W e w illd elay the analysisofthisquestionuntilthe next c hapter and w e w illtake the M F N rule asgivenat thisstage. 6 M FN R egim e vs.B il ateralR egim e T he ¯nalquestionto b e asked isw hether the governm entsw ould pref er a multilateralnegotiationenvironm ent w ith the M F Nc lause or a b ilateralenvironm ent that allow sd isc rim inatory 23 tari®s. W ith the im positionofthe M F N rule, w e c annot d irec tly c laim that multilateral negotiationsc anprovid e a P areto superior outc om e und er allc irc um stances.T he answ er w ill d epend onw hic h equilib rium outc om e provid esthe higher w elf are levels.M ore spec i¯c ally, the M F Nregim e w illd e¯nitelyb e c hosenifallgovernm entsare b etter o® inthat equilib rium . T hisquestionisd i± c ult to answ er since w e im posed no restric tionsso f ar onthe shapesof the payo® f unctionsand other param etersother thansom e very generalassum ptions.It is quite c onceivab le that M F N regim e c anb e pref erred , and thusenf orc eab le, und er c ertain c ond itions. Inthissec tion,w e w illprovid e one such exam ple w ith som e restric tive assum ptionsw hich are ac tually im posed quite of teninthe internationaltrad e literature.W e w illassum e that the c ountriesare symm etric inevery sense possib le: (1) T he im port payo® f unctionUAM (¿ab;¿ac) w illb e sym m etric inb oth param etersand thishold sf or other governm ents. (2 ) T he export f unctionsf or A f or b oth export good s,UAX (¿ba ;¿bc) and U AX (¿ca;¿cb) w ill b e id entic aland thisw illhold f or other governm ents. (3) For A and B w ho c ompete to export good cto c ountry C ; their export f unction UAX (¿ca ;¿cb) and UBX (¿cb;¿ca) w illb e id entic al. T hese c ond itionsw ould b e met iftw o c ountriesexporting the sam e good had the sam e end ow m ents and the supply f unctions f or allgood s w ere id entic al. Form these, w e w ill assum e that the equilib rium outc om es are id entic alas w ell. Inother w ord s, the tari®s, ¿B = ³ ´ B B B B B B ¿ab ;¿ac ;¿ba ;¿bc ;¿c tab lished inthe netw orkofb ilateralgam esw illb e equalto a ;¿c b ; es eac h other.T he questionb ec omesifthere isanequilib rium outc om e ofa m ultilateralM F N b argaining game that P areto im provesuponthe b ilateraloutc om e. T he f ollow ing result answ ersthisquestion: P rop osition8 : Inthe symmetric case, there isanM F N outcom e that isP areto superior to the bilateralnetw orkoutcome. 24 P roof :See the append ix. T hisexample show sthat the M F N c ase P areto im provesuponthe b ilateralc ase.Since allgovernm entsare b etter o®.none w illw ant to d eviate f rom the M F N rule w hich w ould imply returningto the d isc riminatory b ilateralregim e. 7 Con cl usions T hispaper approac hesthe w orld trad ingsystem f rom a verygeneralb argainingperspec tive as it isd one b y m any polic ym akersand governm ent o± c ials.T hisapproach hasthe ad vantage ofexplainingmanyob servationssuc h asthe m erc antilist b ehavior ofthe governm entsd uring the negotiationround s.How ever,our m ainaim isto d eterm ine the sourc esofe± c iencygains inmultilateralnegotiationssuc h asthe G AT T /W T O sponsored negotiationround s. T he ¯rst sourc e ofe± c iencygainsarisessince multilateralism allow sthe negotiatingpartiesto equate the ratiosoftheir marginalpayo®s.T hisisw hat agentsw ould d o ina general equilib rium exc hange ec onomy to reach P areto superior outc om es.M ultilateralism provid es thisgainevenw henthe trad e regim e isc om posed ofind epend ent b ilateralrelationships. T he sec ond sourc e ofgainsarisessince m ultilateralism allow sc ountriesto internaliz e the (negative) externalitiesim posed b y (m ostly trad e d iverting) b ilateral/regionalagreements onthird parties.T hisissim ilar to the e± c iency gainsthat b ilateralagreem entsprovid e over unilateralac tions.Although,the M F N rule lim itsthe w elf are gainsthat w ould b e availab le ina generalf ram ew ork,w e show that ina sym m etric c ase,m ultilateralM F N outc om esare stillsuperior to b ilateraloutc om es. Inshort, multilateralnegotiationsallow (1) trad ing oftari®sand other b arriersac ross c ountriesthrough b argaining and (2 ) internaliz ationofallunilateraland c oalitionalexternalities. E ± c iency gainsare ob tained through anexpansionofthe f easib le set to includ e P areto superior outc om es(c ompared to unilateraland b ilateraloutc om es).W e show that, w ith no transac tionc osts, the ind ivid ualand totalw elf are are m onotonic ally increasing in 25 the numb er ofc ountries.B est outc om esare ob tained w henallissuesare negotiated simultaneously amongallofthe c ountries.Certainextensionsto ac c om m od ate politic alec onomy e®ec tsare includ ed to explainw hy w e never see c om pletely f ree trad e. W e d em onstrated the ab ove resultsusing a very spec ializ ed generalequilib rium m od el since it sim pli¯ed the analysis c onsid erab ly. How ever, the results c anb e easily c arried to other settings, espec ially strategic trad e m od els. T he im portant step is to introd uc e the e®ec ts ofb ilateraland /or multilateralb argaining and to c om pare these to outc om es w ith unilateralac tions. Since, the w orld trad ing system is c harac teriz ed b y c ontinuous negotiations,w e b elieve it isc ruc ialto analyz e trad e polic iesina b argainingf ram ew ork. T he e± c iencygainsf rom multilateralism arise f rom the nature ofthe und erlyingec onom ic environm ent and trad e relationships.How ever, asw e stated earlier, suc c essf ulmultilateral negotiationshave b eenonly estab lished inthe post-w ar era w ithinthe G AT T regim e.T he f ailure to exploit the P areto superior outc om es provid ed b y multilateralnegotiations in the past, w e b elieve, is d ue to the institutionalf ram ew ork inw hic h trad e polic ies w ere f ormulated .inthe next c hapter, w e w illanalyz e the negotiationprinciplesand other rules w ithinthe G AT T system that enab led the m em b er c ountries to estab lish and sustaina suc c essf ulmultilateralregim e. F inally,thisanalysishelpsusto id entif y the strengthsofG AT T /W T O w hich isa c ruc ial task at this stage. G AT T /W T O b ased non-d isc rim inatory m ultilateralsystem is f ac ing seriousc hallengesand going through m ajor institutionalc hanges.Correc t id enti¯c ationof strengthsand w eaknessesofthe trad ing system w ould enab le usto d esignm ore e± c ient and °exib le rulesand a negotiationf ram ew orkto hand le the c om plic ated issuesonthe trad e agend a.W e b elieve G AT T /W T O should b e the pillar ofthe w orld trad ingsystem since nond isc rim inatorymultilateralism hasthe potentialto d eliver the m axim um payo®sto c ountries and avoid possib le ine± c iencies.It isc ruc ialto end ow the W T O w ith the right m ec hanism s since the next d ec ad e w illd etermine itsand the w orld trad ingsystem 'sf uture. 26 8 Append ix P roofofP rop osition2 : T he e± c iency oftrad e agreem entsrequiresthat equation(5) hold s. T hisim pliesthat d U A=d ¿j d U A=d ¿i = d U B =d ¿j :De¯ne d U B =d ¿i f unctionW (¿i;¿j) = d UA d UB d ¿j d ¿i ¡ ddU¿Ai ddU¿Bj : Lookat the loc usW (¿i;¿j) = 0 w hich im plic itlyd e¯nesthe e± c ient tari® pointsonthe c ontrac t c urve.Since the d emand f unctionsare linear and the c onsum er surplusesare quad ratic , eac h d erivative inW (¿i;¿j) islinear initsargum ent.T henw e c anw rite d UA d ¿i d UB d ¿i d UA d ¿j = a ¡b¿j and = c ¿i ¡d w here a;b;c ;d are allpositive c onstants.B ec ause ofsym m etry, w e w illhave = a ¡b¿i and d UB d ¿j = c ¿j¡d .T henf or the tari® pointssatisf yingW (¿i;¿j) = 0 ; w e c an d eterm ine dd ¿¿ji,the slope ofthe e± c iencyloc us.Af ter sub stitutingthe ab ove linear equations, w e ¯nd that ³ h i d ¿i d ¿j W (¿ ;¿ )= 0 i j < 0 and · ¸ d 2 ¿i 2 d ¿j W (¿i;¿j)= 0 < 0 f or alle± c ient pairs(¿i;¿j). P roofofP rop osition3: Let ¸ b e the Lagrange m ultiplier at the optim alpoint ´ UAab;UBab ofthe b ilateralb argaining gam e b etw eenA and B . Sim ilarly d e¯ne ¹ f or ³ ´ (UAac;UCac) and ´ f or UBbc;U Cbc :Suppose ´ ·¹=¸.Note that ¸ isalso the rate oftransf or- m ationb etw eenthe payo®sofc ountry A and B b y d e¯nition.T he sam e hold sf or ´ and ¹ : Inthe trilateralb argaininggam e,w e have £ asthe rate oftransf orm ationb etw eenpayo®sof c ountriesA and B and ¢ f or c ountriesA and C asgivenb y expression7.Furtherm ore,on the e± c ient f rontier w e need to have ¢ =£ asthe rate oftransf orm ationb etw eenc ountries B and C .Since, ´ · ¹ =¸, the outc om e ofb ilateralnegotiationsc annot b e onthe payo® f rontier oftrilateralnegotiations.T hus,givenany outc om e ofb ilateralnegotiations,w e c an ¯nd a trilateralnegotiationoutc ome that P areto d om inatesit. P roofofCorol l ary 4 : Since the initialc ountriesare onthe f rontier,there are no b arter trad e opportunitiesofthe sort d esc rib ed previously.Let sab d enote the slope ofthe b ilateral payo® f rontier b etw eenc ountry A and B at the outc om e d ec id ed d uring the multilateral negotiations.san d enotesthe slope ofthe b ilateralpayo® f rontier b etw eenc ountry A and N at their b ilateralagreem ent point.Let abc d :::k d enote anord ering oflength K ofsom e of the c ountriesinmultilateralnegotiationinitially.Suppose sabsbc:::skn ·san .T henusingthe trad ingm ethod d esc rib ed ab ove,it ispossib le im prove any c ountry'spayo® w ithout hurting 27 the other ones. T husinclusionofc ountry N increasesthe siz e ofthe P areto f rontier and c reatesopportunitiesto improve the w elf are ofallc ountries. P roofofP roposition6:Suppose ¿ B = ³ ´ B B B B B B ¿ab ;¿ba ;¿ac ;¿bc ;¿c ob ale± a ;¿c b isonthe gl c iency f rontier d e¯ned b y (9).T henit should b e the solutionto a m axim iz ationprob lem of the f ollow ingtype: ¿ B = argmax[U A (¿)]p [UB (¿)]q [UC (¿)]1¡p¡q (11) w here 1 > p > 0 ;1 > q > 0 ;1 > p + q > 0 :Inother w ord s, suc h p and q should exist.W e know that the f ollow inghold at ¿ B f rom the ¯rst-ord er c ond itionsofequation(10 ): d UB =d ¿ab d U A=d ¿ab + (1 ¡® ) = UA UB d U A=d ¿ba d UB =d ¿ba (® ) + (1 ¡® ) = UA UB (® ) 0; 0 Also,the f ollow inghold at ¿ B f rom the ¯rst ord er c ond itionofequation(11): d UB =d ¿ab d UC =d ¿ab d UA=d ¿ab + (q) + (1 ¡p ¡q) = UA UB UC d UA=d ¿ba d UB =d ¿ba d UC =d ¿ba (p) + (q) + (1 ¡p ¡q) = UA UB UC 0 (p) 0 R earrangingthe ab ove equationsand sub stitutionyield s µ ¶ 1 ¡® d UB =d ¿ab d UC =d ¿ab q ¡p + (1 ¡p ¡q) = ® UB UC µ ¶ 1 ¡® d UB =d ¿ba d UC =d ¿ba q ¡p + (1 ¡p ¡q) = ® UB UC 0 0 W e know that d UC =d ¿ab > 0 ;d UB =d ¿ab < 0 and (1 ¡p ¡q) > 0 .So the ¯rst equationrequires ³ that q ¡p 1¡® ® ´ ³ > 0 :Also, d UC =d ¿ba > 0 and d UB =d ¿ba > 0 w hich im plies q ¡p 1¡® ® ´ < 0: B ut thisisnot possib le, so no suc h (p;q) c anexist and theref ore ¿ B il c annot b e glob ally e± c ient. P roofofP rop osition7: Since the optim izationprob lem ofthe M F N c ase hasthe same ob jec tive f unctionw ith ad d itionalc onstraints,the outc om e hasa low er value.Inother 28 w ord sF G e n (U B ;U C ) ¸F M FN (U B ;U C ) f or allpairsof(U B ;U C ):T heref ore,the outc om e of negotiationsw ith no restric tionsP areto d om inatesthe outc om e ofnegotiationsw ith M F N c onstraint. P roofofP roposition8: Anoutc om e,¿ M FN ; ofthe multilateralM F Nb argaininggam e hasto b e a solutionto the f ollow ingprob lem : ¿M FN = argm ax[UA (¿)]® [UB (¿)]¯ [UC (¿)]1¡® ¡¯ w here 1 > ¯ > 0 ;1 > ® > 0 ;1 > ® + ¯ > 0 :T o c om plete the proof , w e need to show that one pair of(® ;¯ )existsw hic h satisf y the ab ove equation.Let ® = ¯ = 1=3.T henthe ¯rst c ond itions(w hen¿a = ¿aM " d UA d ¿a # FN ) b ec ome + ¿a = ¿aM FN " d UB d ¿a # + ¿a = ¿aM FN " d UC d ¿a # = 0 ¿a = ¿aM FN d ue to the f ac t that UA = UB = UC . Sam e hold s f or other tari® rates as w ell. Since tari® ratesinthe b ilateralc ase are equal,w e c anassum e that the c ountriesare at the Nash b argaining solution. T he ¯rst ord er c ond itionsf or ¿ab inthe b ilateralnetw ork c ase (w hen B ¿ab = ¿ab ) is: " d UA d ¿ab # + ¿ab= BIL ¿ab " d UA d ¿ab B Since d UC =d ¿a < 0 , w e must have that ¿ab > ¿aM # = 0 ¿ab= FN B IL ¿ab B . Since thishold sf or ¿ab , it w illhold f or alltari® rates. T his w ould imply that the payo®s ofallc ountries inthe M F N c ase ³ UAM F N ;UBM FN ;UCM FN ´ ³ ´ ishigher thanthe payo®sinthe b ilateralnetw orkc ase U AB il;UBB il;UCB il . 29 R ef erences [1] B agw ell, K yle and R ob ert Staiger [19 96], \R ec iproc alT rad e Lib eraliz ation," NB E R W orkingP aper #54 88. [2 ] B agw ell,K yle and R ob ert Staiger [199 7a],\G AT T -T hink,"m im eo. [3] B agw ell, K yle and R ob ert Staiger [19 97b ], \R ec iproc ity, Non-Disc rim inationand P ref erentialAgreem entsinthe M ultilateralT rad ingSystem ,"NB E R W orkingP aper #59 32 . 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