Transportation, wholesaling, and retailing activities are a significant segment of economic activity in many economies. The magnitude of these activities can vary greatly between products, users, and regions. However, in most applied general equilibrium (AGE) analyses, these marketing activities are not tied to specific commodities. This paper develops a model framework and database that incorporates domestic marketing margins on domestic and imported goods going to final demand or used as intermediate inputs, and margins on exports, into the standard GTAP Model. The effects of incorporating domestic marketing activities into an AGE model are illustrated by comparing the results of the standard GTAP Model to the new GTAP-M Model for several different technological change scenarios. The comparison yields two main results. First, tying the domestic marketing activities to specific commodities changes the degree of price transmission from producers to users, compared to a model that does not include margin activities explicitly. The second main result is that the magnitude of the elasticity of substitution between commodities and the composite marketing activity is very important. Allowing variable margins creates a new source of demand-responsiveness for commodities which can significantly alter the results of policy simulations.
{"title":"GTAP-M: A GTAP Model and Data Base that Incorporates Domestic Margins","authors":"E. Peterson","doi":"10.21642/gtap.tp26","DOIUrl":"https://doi.org/10.21642/gtap.tp26","url":null,"abstract":"Transportation, wholesaling, and retailing activities are a significant segment of economic activity in many economies. The magnitude of these activities can vary greatly between products, users, and regions. However, in most applied general equilibrium (AGE) analyses, these marketing activities are not tied to specific commodities. This paper develops a model framework and database that incorporates domestic marketing margins on domestic and imported goods going to final demand or used as intermediate inputs, and margins on exports, into the standard GTAP Model. The effects of incorporating domestic marketing activities into an AGE model are illustrated by comparing the results of the standard GTAP Model to the new GTAP-M Model for several different technological change scenarios. The comparison yields two main results. First, tying the domestic marketing activities to specific commodities changes the degree of price transmission from producers to users, compared to a model that does not include margin activities explicitly. The second main result is that the magnitude of the elasticity of substitution between commodities and the composite marketing activity is very important. Allowing variable margins creates a new source of demand-responsiveness for commodities which can significantly alter the results of policy simulations.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127507600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huey-Lin Lee, T. Hertel, B. Sohngen, N. Ramankutty
This paper describes the GTAP Land Use Data Base designed to support integrated assessments of the potential for greenhouse gas mitigation. It disaggregates land use by agro-ecological zone (AEZ). To do so, it draws upon global land cover data bases, as well as state-of-the-art definition of AEZs from the FAO and IIASA. Agro-ecological zoning segments a parcel of land into smaller units according to agro-ecological characteristics, including: precipitation, temperature, soil type, terrain conditions, etc. Each zone has a similar combination of constraints and potential for land use. In the GTAP-AEZ Data Base, there are 18 AEZs, covering six different lengths of growing period spread over three different climatic zones. Land using activities include crop production, livestock raising, and forestry. In so doing, this extension of the standard GTAP Data Base permits a much more refined characterization of the potential for shifting land use amongst these different activities. When combined with information on greenhouse gas emissions, this data base permits economists interested in integrated assessment of climate change to better assess the role of land use change in greenhouse gases mitigation strategies.
{"title":"Towards An Integrated Land Use Database for Assessing the Potential for Greenhouse Gas Mitigation","authors":"Huey-Lin Lee, T. Hertel, B. Sohngen, N. Ramankutty","doi":"10.21642/gtap.tp25","DOIUrl":"https://doi.org/10.21642/gtap.tp25","url":null,"abstract":"This paper describes the GTAP Land Use Data Base designed to support integrated assessments of the potential for greenhouse gas mitigation. It disaggregates land use by agro-ecological zone (AEZ). To do so, it draws upon global land cover data bases, as well as state-of-the-art definition of AEZs from the FAO and IIASA. Agro-ecological zoning segments a parcel of land into smaller units according to agro-ecological characteristics, including: precipitation, temperature, soil type, terrain conditions, etc. Each zone has a similar combination of constraints and potential for land use. In the GTAP-AEZ Data Base, there are 18 AEZs, covering six different lengths of growing period spread over three different climatic zones. Land using activities include crop production, livestock raising, and forestry. In so doing, this extension of the standard GTAP Data Base permits a much more refined characterization of the potential for shifting land use amongst these different activities. When combined with information on greenhouse gas emissions, this data base permits economists interested in integrated assessment of climate change to better assess the role of land use change in greenhouse gases mitigation strategies.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125330615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Global models of agricultural trade have a long and distinguished history. The introduction of the GTAP data base and modeling project represented a significant advance forward as it put modelers and trade policy analysts on common ground. After an initial generation of GTAP based modeling of agricultural trade policy using the standard modeling framework, individual researchers have begun introducing agricultural specificity into the standard modeling framework in order to better capture the particular features of the agricultural economy pertinent to their research questions. This technical paper follows in that same tradition by reviewing important linkages between international trade and the farm and food economy and introducing them into the standard GTAP modeling framework, offering a special purpose version of the model nicknamed GTAP-AGR. We introduce this agricultural specificity by introducing new behavioral relationships into the standard GTAP framework. We focus particular attention on the factor markets, which play a critical role in determining the incidence of producer subsidies. This includes modifying both the factor supply and derived demand equations. We also modify the specification of consumer demand, assuming separability of food from non-food commodities. Finally, we introduce the important substitution possibilities amongst feedstuffs used in the livestock sector. Where possible we support these new behavioral relationships with literature-based estimates of both the mean and standard deviation of behavioral parameters. The express purpose of this is to support systematic sensitivity analysis with respect to policy reform scenarios performed with GTAP-AGR. In addition to documenting these extensions to the standard modeling framework, the paper has an additional goal, and that is to gauge the performance of the GTAP-AGR model and how it differs from the standard GTAP framework. We do this primarily by comparing the farm level supply and demand response in terms of policy incidence for the two frameworks. In addition, we evaluate the ability of both models to reproduce observed price volatility in an effort to validate the performance of these models. Finally, we evaluate the results of the two models in a side-by-side comparison of results from full liberalization of agricultural and non-agricultural support.
{"title":"GTAP-AGR: A Framework for Assessing the Implications of Multilateral Changes in Agricultural Policies","authors":"R. Keeney, T. Hertel","doi":"10.21642/gtap.tp24","DOIUrl":"https://doi.org/10.21642/gtap.tp24","url":null,"abstract":"Global models of agricultural trade have a long and distinguished history. The introduction of the GTAP data base and modeling project represented a significant advance forward as it put modelers and trade policy analysts on common ground. After an initial generation of GTAP based modeling of agricultural trade policy using the standard modeling framework, individual researchers have begun introducing agricultural specificity into the standard modeling framework in order to better capture the particular features of the agricultural economy pertinent to their research questions. This technical paper follows in that same tradition by reviewing important linkages between international trade and the farm and food economy and introducing them into the standard GTAP modeling framework, offering a special purpose version of the model nicknamed GTAP-AGR. We introduce this agricultural specificity by introducing new behavioral relationships into the standard GTAP framework. We focus particular attention on the factor markets, which play a critical role in determining the incidence of producer subsidies. This includes modifying both the factor supply and derived demand equations. We also modify the specification of consumer demand, assuming separability of food from non-food commodities. Finally, we introduce the important substitution possibilities amongst feedstuffs used in the livestock sector. Where possible we support these new behavioral relationships with literature-based estimates of both the mean and standard deviation of behavioral parameters. The express purpose of this is to support systematic sensitivity analysis with respect to policy reform scenarios performed with GTAP-AGR. In addition to documenting these extensions to the standard modeling framework, the paper has an additional goal, and that is to gauge the performance of the GTAP-AGR model and how it differs from the standard GTAP framework. We do this primarily by comparing the farm level supply and demand response in terms of policy incidence for the two frameworks. In addition, we evaluate the ability of both models to reproduce observed price volatility in an effort to validate the performance of these models. Finally, we evaluate the results of the two models in a side-by-side comparison of results from full liberalization of agricultural and non-agricultural support.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114652253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports a method for converting versions 5 and 6 of the GTAP Data Base into a global SAM that is stored in both the GAMS data exchange (GDX) and Header Array (HAR) formats. The focus of attention is on the generation of a SAM representation of the GTAP Data Base that is fully consistent with the GTAP model; as such the resultant SAM can be readily used to calibrate a version of the GTAP model that had been coded in GAMS. The GAMS code used to generate the SAM representation of the GTAP Data Base is provided as a GAMS model library – this code has been tested with versions 5.3, 5.4 and 6.0 (pre release 5) of the GTAP Data Base. Keywords: Social Accounting Matrix, Trade Analysis, Computable General Equilibrium.
{"title":"Deriving a Global Social Accounting Matrix from GTAP Versions 5 and 6 Data","authors":"S. Mcdonald, K. Thierfelder","doi":"10.21642/gtap.tp22","DOIUrl":"https://doi.org/10.21642/gtap.tp22","url":null,"abstract":"This paper reports a method for converting versions 5 and 6 of the GTAP Data Base into a global SAM that is stored in both the GAMS data exchange (GDX) and Header Array (HAR) formats. The focus of attention is on the generation of a SAM representation of the GTAP Data Base that is fully consistent with the GTAP model; as such the resultant SAM can be readily used to calibrate a version of the GTAP model that had been coded in GAMS. The GAMS code used to generate the SAM representation of the GTAP Data Base is provided as a GAMS model library – this code has been tested with versions 5.3, 5.4 and 6.0 (pre release 5) of the GTAP Data Base. Keywords: Social Accounting Matrix, Trade Analysis, Computable General Equilibrium.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133866792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Duty drawback schemes, which typically involve a combination of duty rebates and exemptions, are a feature of many countries' trade regimes. They are used in highly protected, developing economies as means of providing exporters with imported inputs at world prices, and thus increasing their competitiveness, while maintaining the protection on the rest of the economy. In China duty exemptions have been central to the process of trade reform and have led to a tremendous increase in processed exports utilizing imported materials. Despite the widespread use and importance of duty drawbacks, these "new trade liberalization" instruments have been given relatively little attention in empirical multilateral trade liberalization studies. This paper presents an empirical multi-region trade model GTAP-DD, an extension of GTAP, in which the effects of policy reform are differentiated based on the trade-orientation of the firms. Both GTAP and GTAP-DD are used to analyze the impact of China's WTO accession, which involves liberalization in China from 1997 to post-accession tariffs among a number of other liberalization measures. The analysis shows that failure to account of duty exemptions in the case of China's recent WTO accession will overstate the increase in : (a) China's trade flows by 40 percent, (b) China's welfare by 15 percent, and (c) exports of selected sectors by as much as 90 percent. The magnitude of the bias depends on the level of pre-intervention tariffs and the size of tariff cuts - the larger the initial distortions and tariff reductions, the larger the bias when duty drawbacks are ignored. The bias in GTAP's estimates of China's real GDP, trade flows and welfare changes due to WTO accession increases more three times when China's pre-intervention tariffs are raised from their 1997 levels to the much higher 1995 levels. These results suggest that trade liberalization studies focusing on economies in which protection is high, import concessions play an important role and planned tariff cuts are deep, must treat duty drawbacks explicitly in order to avoid serious errors in their estimates of sectoral, trade flows and welfare changes.
{"title":"GTAP-DD: A Model for Analyzing Trade Reforms in the Presence of Duty Drawbacks","authors":"Elena Ianchovichina","doi":"10.21642/gtap.tp21","DOIUrl":"https://doi.org/10.21642/gtap.tp21","url":null,"abstract":"Duty drawback schemes, which typically involve a combination of duty rebates and exemptions, are a feature of many countries' trade regimes. They are used in highly protected, developing economies as means of providing exporters with imported inputs at world prices, and thus increasing their competitiveness, while maintaining the protection on the rest of the economy. In China duty exemptions have been central to the process of trade reform and have led to a tremendous increase in processed exports utilizing imported materials. Despite the widespread use and importance of duty drawbacks, these \"new trade liberalization\" instruments have been given relatively little attention in empirical multilateral trade liberalization studies. This paper presents an empirical multi-region trade model GTAP-DD, an extension of GTAP, in which the effects of policy reform are differentiated based on the trade-orientation of the firms. Both GTAP and GTAP-DD are used to analyze the impact of China's WTO accession, which involves liberalization in China from 1997 to post-accession tariffs among a number of other liberalization measures. The analysis shows that failure to account of duty exemptions in the case of China's recent WTO accession will overstate the increase in : (a) China's trade flows by 40 percent, (b) China's welfare by 15 percent, and (c) exports of selected sectors by as much as 90 percent. The magnitude of the bias depends on the level of pre-intervention tariffs and the size of tariff cuts - the larger the initial distortions and tariff reductions, the larger the bias when duty drawbacks are ignored. The bias in GTAP's estimates of China's real GDP, trade flows and welfare changes due to WTO accession increases more three times when China's pre-intervention tariffs are raised from their 1997 levels to the much higher 1995 levels. These results suggest that trade liberalization studies focusing on economies in which protection is high, import concessions play an important role and planned tariff cuts are deep, must treat duty drawbacks explicitly in order to avoid serious errors in their estimates of sectoral, trade flows and welfare changes.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115778147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Energy is an important commodity in many economic activities. Its usage affects the environment via CO2 emissions and the Greenhouse Effect. Modeling the energy-economy-environment-trade linkages is an important objective in applied economic policy analysis. Previously, however, the modeling of these linkages in GTAP has been incomplete. This is because energy substitution, a key factor in this chain of linkages, is absent from the standard model specification. This technical paper remedies this deficiency by incorporating energy substitution into the standard GTAP model. It begins by first reviewing some of the existing approaches to this problem in contemporary CGE models. It then suggests an approach for GTAP which incorporates some of these desirable features of energy substitution. The approach is implemented as an extended version of the GTAP model called GTAP-E, which includes the standard GTAP model as a special case. In addition, GTAP-E incorporates carbon emissions from the combustion of fossil fuels and this revised version of GTAP-E provides for a mechanism to trade these emissions internationally. The resulting behavior of agents in the model is analyzed using general equilibrium demand elasticities which summarize the combined effect of the new model specification. Implications for policy analysis are demonstrated via a simple simulation experiment in which global carbon emissions are reduced via a carbon tax. Results show that incorporating energy substitution into GTAP is essential for conducting analysis of this problem. The policy relevance of GTAP-E in the context of the existing debate about climate change is illustrated by some simulations of the implementation of the Kyoto Protocol. It is hoped that the proposed model will be used by individuals in the GTAP network who may not be themselves energy modelers, but who require a better representation of the energy-economy linkages than is currently offered in the standard GTAP model.
{"title":"GTAP-E: An Energy-Environmental Version of the GTAP Model","authors":"T. Truong","doi":"10.21642/gtap.tp16","DOIUrl":"https://doi.org/10.21642/gtap.tp16","url":null,"abstract":"Energy is an important commodity in many economic activities. Its usage affects the environment via CO2 emissions and the Greenhouse Effect. Modeling the energy-economy-environment-trade linkages is an important objective in applied economic policy analysis. Previously, however, the modeling of these linkages in GTAP has been incomplete. This is because energy substitution, a key factor in this chain of linkages, is absent from the standard model specification. This technical paper remedies this deficiency by incorporating energy substitution into the standard GTAP model. It begins by first reviewing some of the existing approaches to this problem in contemporary CGE models. It then suggests an approach for GTAP which incorporates some of these desirable features of energy substitution. The approach is implemented as an extended version of the GTAP model called GTAP-E, which includes the standard GTAP model as a special case. In addition, GTAP-E incorporates carbon emissions from the combustion of fossil fuels and this revised version of GTAP-E provides for a mechanism to trade these emissions internationally. The resulting behavior of agents in the model is analyzed using general equilibrium demand elasticities which summarize the combined effect of the new model specification. Implications for policy analysis are demonstrated via a simple simulation experiment in which global carbon emissions are reduced via a carbon tax. Results show that incorporating energy substitution into GTAP is essential for conducting analysis of this problem. The policy relevance of GTAP-E in the context of the existing debate about climate change is illustrated by some simulations of the implementation of the Kyoto Protocol. It is hoped that the proposed model will be used by individuals in the GTAP network who may not be themselves energy modelers, but who require a better representation of the energy-economy linkages than is currently offered in the standard GTAP model.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131388777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huff and Hertel (2001) derive a welfare decomposition for the equivalent variation in the GTAP model. The derivation appears to be very specific to GTAP. Nevertheless, it contains nearly all the ingredients required for performing welfare decomposition for any CGE model. In this paper, the approach of Huff and Hertel (2001) is generalised to derive a welfare decomposition that can be applied to most, if not all, CGE models. General production and utility functions are accommodated, as are foreign income flows. A brief guide to coding the proposed welfare decomposition in GEMPACK is also provided. The decomposition is applied to decomposing the equivalent variation in GTAP.
{"title":"A General Welfare Decomposition for CGE Models","authors":"K. Hanslow","doi":"10.21642/gtap.tp19","DOIUrl":"https://doi.org/10.21642/gtap.tp19","url":null,"abstract":"Huff and Hertel (2001) derive a welfare decomposition for the equivalent variation in the GTAP model. The derivation appears to be very specific to GTAP. Nevertheless, it contains nearly all the ingredients required for performing welfare decomposition for any CGE model. In this paper, the approach of Huff and Hertel (2001) is generalised to derive a welfare decomposition that can be applied to most, if not all, CGE models. General production and utility functions are accommodated, as are foreign income flows. A brief guide to coding the proposed welfare decomposition in GEMPACK is also provided. The decomposition is applied to decomposing the equivalent variation in GTAP.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116018605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Explicit modeling of tariff rate quotas (TRQs) is important in the current World Trade Organization negotiations. In order to do such modeling with GTAP, extra data is required and extra equations must be added to the model. This paper provides tools for assisting modelers to carry out explicit modeling of bilateral tariff rate quotas in GTAP using GEMPACK. The paper describes how the extra data for sugar TRQ applications was obtained and reconciled with the standard GTAP data. Supplied with the paper is a TABLO Input file TRQDATA.TAB which others can use for reconciling their TRQ data with the usual GTAP data. Supplied with the paper is a module which can be added to the standard TABLO Input files for GTAP. This module contains the extra equations required to model TRQs. Detailed hands-on examples are supplied with the paper, as is a TRQ application relating to a partial liberalization of sugar TRQ. Readers of the paper can replicate these applications. A windows interface TRQmate is supplied with the paper. This is a relatively general-purpose interface which automates the steps in carrying out TRQ applications with GTAP and GEMPACK. If you wish to carry out your own bilateral TRQ applications with GTAP and GEMPACK, the tools supplied with this paper will make it relatively straightforward for you to do so once you have collected the extra data you need.
{"title":"Implementing Bilateral Tariff Rate Quotas in GTAP using GEMPACK","authors":"A. Elbehri, K. Pearson","doi":"10.21642/gtap.tp18","DOIUrl":"https://doi.org/10.21642/gtap.tp18","url":null,"abstract":"Explicit modeling of tariff rate quotas (TRQs) is important in the current World Trade Organization negotiations. In order to do such modeling with GTAP, extra data is required and extra equations must be added to the model. This paper provides tools for assisting modelers to carry out explicit modeling of bilateral tariff rate quotas in GTAP using GEMPACK. The paper describes how the extra data for sugar TRQ applications was obtained and reconciled with the standard GTAP data. Supplied with the paper is a TABLO Input file TRQDATA.TAB which others can use for reconciling their TRQ data with the usual GTAP data. Supplied with the paper is a module which can be added to the standard TABLO Input files for GTAP. This module contains the extra equations required to model TRQs. Detailed hands-on examples are supplied with the paper, as is a TRQ application relating to a partial liberalization of sugar TRQ. Readers of the paper can replicate these applications. A windows interface TRQmate is supplied with the paper. This is a relatively general-purpose interface which automates the steps in carrying out TRQ applications with GTAP and GEMPACK. If you wish to carry out your own bilateral TRQ applications with GTAP and GEMPACK, the tools supplied with this paper will make it relatively straightforward for you to do so once you have collected the extra data you need.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"31 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122940110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2000-12-03DOI: 10.1017/CBO9781139059923.002
Elena Ianchovichina, Robert McDougall
This paper documents the foreign asset ownership and investment theory of the dynamic GTAP model (GTAP-Dyn). The new investment theory offers a disequilibrium approach to modeling endogenously international capital mobility. It permits a recursive solution procedure, a feature that allows easy implementation of dynamics into any static AGE model without imposing limitations on the model's size. The method involves treating time as a variable, not as an index. Having time as a variable allows the construction of dynamic GTAP with minimum modifications to the existing structure of GTAP, by separating the theory of static GTAP from the length of run.
{"title":"Theoretical Structure of Dynamic GTAP","authors":"Elena Ianchovichina, Robert McDougall","doi":"10.1017/CBO9781139059923.002","DOIUrl":"https://doi.org/10.1017/CBO9781139059923.002","url":null,"abstract":"This paper documents the foreign asset ownership and investment theory of the dynamic GTAP model (GTAP-Dyn). The new investment theory offers a disequilibrium approach to modeling endogenously international capital mobility. It permits a recursive solution procedure, a feature that allows easy implementation of dynamics into any static AGE model without imposing limitations on the model's size. The method involves treating time as a variable, not as an index. Having time as a variable allows the construction of dynamic GTAP with minimum modifications to the existing structure of GTAP, by separating the theory of static GTAP from the length of run.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"605 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132786456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In economic simulation, results often hinge crucially on values of key exogenous inputs (the values of the parameters of the model and the shocks applied). Computational burden has, in the past, hindered systematic investigation of the impacts of variations in these key exogenous inputs. In this document, practical methods for conducting systematic sensitivity analysis for any model implemented using the GEMPACK suite of software are documented. The procedures described here are based on GTAP Technical Paper number 2 which sets out the theory behind the Gaussian quadrature methods on which the automated procedure is based. The procedures allow modellers to obtain estimates of the means and standard deviations of any endogenous variables of their model. The model only needs to be solved a relatively modest number of times (usually only 2N times if N exogenous inputs are varying); this is considerably fewer than the number of solves required by Monte Carlo methods. The procedure documented here fully automates solving the model as often as is necessary; once the user sets it up and starts it running, no further intervention is required. The document spells out the assumptions which must be made about the distribution of the exogenous inputs for the methods described to be valid. Five examples of systematic sensitivity computations are presented and the accompanying software allows modellers to work through these examples while reading the document. This should leave readers fully prepared to analyse the sensitivity of results for any model implemented in GEMPACK.
{"title":"Implementing Systematic Sensitivity Analysis Using GEMPACK","authors":"K. Pearson, C. Arndt","doi":"10.21642/gtap.tp03","DOIUrl":"https://doi.org/10.21642/gtap.tp03","url":null,"abstract":"In economic simulation, results often hinge crucially on values of key exogenous inputs (the values of the parameters of the model and the shocks applied). Computational burden has, in the past, hindered systematic investigation of the impacts of variations in these key exogenous inputs. In this document, practical methods for conducting systematic sensitivity analysis for any model implemented using the GEMPACK suite of software are documented. The procedures described here are based on GTAP Technical Paper number 2 which sets out the theory behind the Gaussian quadrature methods on which the automated procedure is based. The procedures allow modellers to obtain estimates of the means and standard deviations of any endogenous variables of their model. The model only needs to be solved a relatively modest number of times (usually only 2N times if N exogenous inputs are varying); this is considerably fewer than the number of solves required by Monte Carlo methods. The procedure documented here fully automates solving the model as often as is necessary; once the user sets it up and starts it running, no further intervention is required. The document spells out the assumptions which must be made about the distribution of the exogenous inputs for the methods described to be valid. Five examples of systematic sensitivity computations are presented and the accompanying software allows modellers to work through these examples while reading the document. This should leave readers fully prepared to analyse the sensitivity of results for any model implemented in GEMPACK.","PeriodicalId":281904,"journal":{"name":"GTAP Technical Paper Series","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127627218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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