GTAP模型应用的一个介绍PPT课件

1、授课：xxx1an introduction to gtap an introduction to gtap applications relevant to applications relevant to escap analytical work in escap analytical work in tradetradea series of information sharing sessions on knowledge acquired through individual trainingmia mikic, tidmore information on www.gtap.ag

2、/授课：xxx2overview on presentationuwhy opting for a general equilibrium analysis?n applied / computable general equilibrium modelsuwhy gtap?uuses for escap analytical work授课：xxx3modelsumodel is a stylized simplification of reality in which behavior is represented by variables and by ass

3、umptions about how they are determined and interact. uthey allow us to frame the analysis in such a way that we are able to think consistently and logically about complex issues, to work out how changes in an economic system matter, and (sometimes) to make predictions about economic performance. 授课：

4、xxx4general equilibriumuold idea: walras (1874), edgeworth (1881), arrow and debreu (1954)xx1y1yua situation where all marketsin an economy are simultaneously in equilibrium, that is, where prices and quantities do not change.pe授课：xxx5partial equilibriumu marshall (1890)equality of supply and demand

5、 in only a subset of an economys markets - usually just one - taking variables from other markets as given. pqdsq1p1e授课：xxx6evaluation of trade liberalizationupartial equilibrium models were most commonly used (at least until relatively recently)ustandard presentation for a so-called “small country

6、fiction”:acbd授课：xxx7so we opt for ge analysis for utheoretical consistency (walras)uaccounting consistency (no double-counting)uinter-industry effects (inter-country effects)uwelfare analysis vs. prices/surplusesuperspectivebetter informed debate and policy analysis 授课：xxx8when not to use ge?uintere

7、st in one sector onlyuinterest in introducing a very complex interpretation of one sector/industryudata not availableutime is not available 授课：xxx9softwarewhat is cge /age analysis?datanew data / solutionconclusionstheory/modelpolicy/shockinout授课：xxx10gtapuglobal trade analysis project - developed a

8、nd coordinated by the center for global trade analysis, purdue university uculture na global network of researchers and policymakers conducting quantitative analysis of international policy issuesncollaboration among academia, public sector and private sectors worldwideua program of distance-plus-re

9、sidential intensive training courses, at purdue and outsideuan annual conference (11th in 2008)uthousands of gtap-based applications available on websiteu24 consortium members supporting gtap financially 授课：xxx11dataudatabase (standalone product)ndetailed inter-industry flows (i-o tables)ntrade flow

10、s (bilateral)nprotection (bilateral from tariff line), supplementary protection datanenergy-use datasee more on /databases/v6/default.asp授课：xxx12modelucurrent model gtap ver 6.2a - family of models (standard-static, dynamic)udescribes global economyuit is applied ge

11、modelusame model structure for each regionulinks the economies through trade flows (and in some way investment)授课：xxx13授课：xxx14gtap model (contd)u96 regions (v.6.2a) and over 100 in v.7 (2008)u57 sectorsueach region balanced (bop=0)ns-net i=x-m= trade balanceuworld is balancednglobal saving=global n

12、et investmentntotal exports=total importsufeatures:nperfect competition and crsnarmington assumptionucomparative static unon-standard featuresndemand from a cde functionnsluggish primary factorsnregional householdnglobal transport sectornglobal bank授课：xxx15policy/shocks/scenariosutrade liberalizatio

13、n (trade reform) policy changes by multiple players uimportant to set endogenous and exogenous variables right in synch with the chosen policy shock授课：xxx16research questions = base for scenariosuimpact of dda globally or for a single economyuimpact of dda on preference erosionuimpact of an expansio

14、n of an existing trading block: (e.g. adding japan to bimstec)uimpact of trade reform in presence of sensitive productsuimpact of trade reform when competition is not perfectuimpact of trade reform when there is labour mobilityuimpact of trade reform on rates of growthuimpact of trade reform on ener

15、gy emissions授课：xxx17softwareugempack urungtapuanalysege授课：xxx18numbers/resultsuri-routhe results of simulations are only as good as the specifications of the models (including parameters) and the data that are fed into them unumbers that come out should only be used to give a sense of the order of m

16、agnitude that a change in policy can mean for economic welfare or trade (forecast or not?)udynamic models estimate larger gains from trade reform授课：xxx19resultsucritical interpretation- using decomposition of welfare resultsusensitivity analysis- changing the models parameters, specifications to det

17、ermine whether the simulation results are significantly affecteduex-post validation needed to increase confidence in the numerical results (long term)授课：xxx20limitations/criticismsuquality of information /sensitivity of the results to assumptions do not warrant assertions of a degree of precision in simulations of the futureuobscured important underlying relationsh