This introductory paper to the special issue on shaping long-term baselines with Computable General Equilibrium (CGE) models presents the main challenges and opportunities in constructing numerical scenarios of future economic activity using CGE models. Better understanding the role of socioeconomic drivers in baseline scenarios allows for better understanding of policy scenarios. The combined set of papers in this special issue provides three key contributions to the literature. First, it highlights the need and room for improved transparency and possibly harmonisation of baseline assumptions, while avoiding herding behaviour where all models make identical assumptions. Secondly, it raises awareness of the crucial role of the baseline in quantitative dynamic CGE analysis. Thirdly, it provides the means and incentives to modelling teams to construct more sophisticated baselines by showing practices used in advanced large-scale models and highlighting the role of different drivers. It is the objective of this special issue to set a research agenda, encouraging greater attention to baseline scenarios in the research literature.
{"title":"Shaping baseline scenarios of economic activity with CGE models: introduction to the special issue","authors":"R. Dellink, D. Mensbrugghe, B. Saveyn","doi":"10.21642/jgea.050101af","DOIUrl":"https://doi.org/10.21642/jgea.050101af","url":null,"abstract":"This introductory paper to the special issue on shaping long-term baselines with Computable General Equilibrium (CGE) models presents the main challenges and opportunities in constructing numerical scenarios of future economic activity using CGE models. Better understanding the role of socioeconomic drivers in baseline scenarios allows for better understanding of policy scenarios. The combined set of papers in this special issue provides three key contributions to the literature. First, it highlights the need and room for improved transparency and possibly harmonisation of baseline assumptions, while avoiding herding behaviour where all models make identical assumptions. Secondly, it raises awareness of the crucial role of the baseline in quantitative dynamic CGE analysis. Thirdly, it provides the means and incentives to modelling teams to construct more sophisticated baselines by showing practices used in advanced large-scale models and highlighting the role of different drivers. It is the objective of this special issue to set a research agenda, encouraging greater attention to baseline scenarios in the research literature.","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42482402","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}
Taran Fæhn, G. Bachner, Robert H. Beach, Jean Château, S. Fujimori, M. Ghosh, M. Hamdi-Chérif, E. Lanzi, S. Paltsev, Toon Vandyck, Bruno S. L. Cunha, Rafael Garaffa, K. Steininger
Limiting global warming in line with the goals in the Paris Agreement will require substantial technological and behavioural transformations. This challenge drives many of the current modelling trends. This article undertakes a review of 17 state-of-the-art recursive-dynamic computable general equilibrium (CGE) models and assesses the key methodologies and applied modules they use for representing sectoral energy and emission characteristics and dynamics. The purpose is to provide technical insight into recent advances in the modelling of current and future energy and abatement technologies and how they can be used to make baseline projections and scenarios 20-80 years ahead. Numerical illustrations are provided. In order to represent likely energy system transitions in the decades to come, modern CGE tools have learned from bottom-up studies. Three different approaches to baseline quantification can be distinguished: (a) exploiting bottom-up model characteristics to endogenize responses of technological investment and utilization, (b) relying on external information sources to feed the exogenous parameters and variables of the model, and (c) linking the model with more technology-rich, partial models to obtain bottom-up- and pathway-consistent parameters.
{"title":"Capturing key energy and emission trends in CGE models: Assessment of Status and Remaining Challenges","authors":"Taran Fæhn, G. Bachner, Robert H. Beach, Jean Château, S. Fujimori, M. Ghosh, M. Hamdi-Chérif, E. Lanzi, S. Paltsev, Toon Vandyck, Bruno S. L. Cunha, Rafael Garaffa, K. Steininger","doi":"10.21642/JGEA.050106AF","DOIUrl":"https://doi.org/10.21642/JGEA.050106AF","url":null,"abstract":"Limiting global warming in line with the goals in the Paris Agreement will require substantial technological and behavioural transformations. This challenge drives many of the current modelling trends. This article undertakes a review of 17 state-of-the-art recursive-dynamic computable general equilibrium (CGE) models and assesses the key methodologies and applied modules they use for representing sectoral energy and emission characteristics and dynamics. The purpose is to provide technical insight into recent advances in the modelling of current and future energy and abatement technologies and how they can be used to make baseline projections and scenarios 20-80 years ahead. Numerical illustrations are provided. In order to represent likely energy system transitions in the decades to come, modern CGE tools have learned from bottom-up studies. Three different approaches to baseline quantification can be distinguished: (a) exploiting bottom-up model characteristics to endogenize responses of technological investment and utilization, (b) relying on external information sources to feed the exogenous parameters and variables of the model, and (c) linking the model with more technology-rich, partial models to obtain bottom-up- and pathway-consistent parameters.","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48777313","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 : 2019-12-25DOI: 10.21642/jgea.040202sm1f
E. Peterson
This paper documents the development of a labor module that incorporates job-search frictions, to introduce unemployment into the standard GTAP model. In this approach, unemployed individuals must search for a job opening and firms that want to hire must search for a worker to fill the job. To illustrate the potential value of a GTAP model with frictional unemployment, the impacts of a 25 percent increase in U.S. tariffs on metal products (e.g., ferrous and non-ferrous metals) are simulated. While employment of skilled and unskilled labor increases in the U.S. metals sector, employment of both types of labor declines in U.S. manufacturing and services sectors. These decreases in employment offset the increase in the metals sector, leading to a 0.8 percent increase in the unemployment of unskilled labor and a 1.5 percent in the unemployment of skilled labor. These increases would translate to a 0.1 percent point increase in the unemployment rate in the U.S. labor market. A potential barrier to wider use of a the GTAP model with unemployment is the availability of job separation or turnover rate data in regions other than the United States. In the example simulation, job turnover rates, and thus the initial levels of matched labor in the non-U.S. regions are assumed to be the same as for United States.
{"title":"Incorporating Unemployment into the GTAP Model","authors":"E. Peterson","doi":"10.21642/jgea.040202sm1f","DOIUrl":"https://doi.org/10.21642/jgea.040202sm1f","url":null,"abstract":"This paper documents the development of a labor module that incorporates job-search frictions, to introduce unemployment into the standard GTAP model. In this approach, unemployed individuals must search for a job opening and firms that want to hire must search for a worker to fill the job. To illustrate the potential value of a GTAP model with frictional unemployment, the impacts of a 25 percent increase in U.S. tariffs on metal products (e.g., ferrous and non-ferrous metals) are simulated. While employment of skilled and unskilled labor increases in the U.S. metals sector, employment of both types of labor declines in U.S. manufacturing and services sectors. These decreases in employment offset the increase in the metals sector, leading to a 0.8 percent increase in the unemployment of unskilled labor and a 1.5 percent in the unemployment of skilled labor. These increases would translate to a 0.1 percent point increase in the unemployment rate in the U.S. labor market. A potential barrier to wider use of a the GTAP model with unemployment is the availability of job separation or turnover rate data in regions other than the United States. In the example simulation, job turnover rates, and thus the initial levels of matched labor in the non-U.S. regions are assumed to be the same as for United States.","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49168237","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 : 2019-12-25DOI: 10.21642/jgea.040203sm1f
A. Gohin
The U.S. farm policy has progressively changed in recent years, with greater reliance on subsidized crop insurance programs in the place of fixed direct payments. Despite the use of such insurance over a long period of time, quantitative macroeconomic assessments of insurance programs are lacking. We develop an original stochastic computable general equilibrium framework where we isolate the coverage effects provided by subsidized insurance programs. We find that their welfare effects are dramatically modified once we recognize their risk sharing properties. Our simulated market effects on the U.S. cereal markets are consistent with currently available microeconometric evidence.
{"title":"General Equilibrium Modelling of the Insurance Industry: U.S. Crop Insurance","authors":"A. Gohin","doi":"10.21642/jgea.040203sm1f","DOIUrl":"https://doi.org/10.21642/jgea.040203sm1f","url":null,"abstract":"The U.S. farm policy has progressively changed in recent years, with greater reliance on subsidized crop insurance programs in the place of fixed direct payments. Despite the use of such insurance over a long period of time, quantitative macroeconomic assessments of insurance programs are lacking. We develop an original stochastic computable general equilibrium framework where we isolate the coverage effects provided by subsidized insurance programs. We find that their welfare effects are dramatically modified once we recognize their risk sharing properties. Our simulated market effects on the U.S. cereal markets are consistent with currently available microeconometric evidence.","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45652594","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 : 2019-06-30DOI: 10.21642/JGEA.040102SM1F
José G. Nuño‐Ledesma, Nelson B. Villoria
{"title":"Estimating International Trade Margins Shares by Mode of Transport for the GTAP Data Base (supplemental materials)","authors":"José G. Nuño‐Ledesma, Nelson B. Villoria","doi":"10.21642/JGEA.040102SM1F","DOIUrl":"https://doi.org/10.21642/JGEA.040102SM1F","url":null,"abstract":"","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41906124","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}
Angel H. Aguiar, M. Chepeliev, Erwin Corong, Robert McDougall, D. Mensbrugghe
This paper highlights the numerous improvements to the Global Trade, Assistance, and Production (GTAP) Data Base, version 10 (also referred to as GTAP 10). The Data Base describes the world economy for 4 reference years (2004, 2007, 2011, and 2014) and distinguishes 65 sectors, up from 57 in the previous release, in each of the 141 countries/regions. The 121 countries in the Data Base account for 98% of world GDP and 92% of world population. For each country/region, the Data Base reports production, intermediate and final uses, international trade and transport margins, and taxes/subsidies. This Data Base underlies most, if not all, applied global general equilibrium models. We use the time series GTAP 10 Data Base to examine the evolution of carbon dioxide emissions embodied in bilateral merchandise and services trade over the 2004-2014 period.
{"title":"The GTAP Data Base: Version 10","authors":"Angel H. Aguiar, M. Chepeliev, Erwin Corong, Robert McDougall, D. Mensbrugghe","doi":"10.21642/JGEA.040101AF","DOIUrl":"https://doi.org/10.21642/JGEA.040101AF","url":null,"abstract":"This paper highlights the numerous improvements to the Global Trade, Assistance, and Production (GTAP) Data Base, version 10 (also referred to as GTAP 10). The Data Base describes the world economy for 4 reference years (2004, 2007, 2011, and 2014) and distinguishes 65 sectors, up from 57 in the previous release, in each of the 141 countries/regions. The 121 countries in the Data Base account for 98% of world GDP and 92% of world population. For each country/region, the Data Base reports production, intermediate and final uses, international trade and transport margins, and taxes/subsidies. This Data Base underlies most, if not all, applied global general equilibrium models. We use the time series GTAP 10 Data Base to examine the evolution of carbon dioxide emissions embodied in bilateral merchandise and services trade over the 2004-2014 period.","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44263387","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}
Since the 1970s, Armington has been the workhorse specification of trade in computable general equilibrium (CGE) models. Under Armington, agents substitute between products from different countries. Conceptually, Melitz provides a more attractive approach in which substitution is between products from different firms rather than countries. Other attractive features of Melitz are monopolistic competition and economies of scale from fixed establishment costs for firms and fixed set-up costs on trade links. In this paper, we show how, with little change to existing code, an Armington model can be converted to Melitz by adding a few equations and introducing closure swaps. We apply our Armington-to-Melitz method to the Armington-based Global Trade Analysis Project (GTAP) model to derive GTAP-Armington-to-Melitz (GTAP-A2M). We show how results from a CGE model with Melitz industries can be interpreted via back-of-the-envelope calculations. In simulations of the effects of a tariff imposed by North America on imports of apparel, we find greater welfare losses for exporting regions under Melitz than under Armington principally because contraction of apparel output in these regions under Melitz generates an increase in the cost to their households of domestic apparel. Finally, we review two other Melitz-based versions of GTAP: GTAP-HET and a recently published model by Bekkers and Francois.
{"title":"Melitz in GTAP Made Easy: the A2M Conversion Method and Result Interpretation","authors":"P. Dixon, M. Jerie, Maureen T. Rimmer","doi":"10.21642/JGEA.040104AF","DOIUrl":"https://doi.org/10.21642/JGEA.040104AF","url":null,"abstract":"Since the 1970s, Armington has been the workhorse specification of trade in computable general equilibrium (CGE) models. Under Armington, agents substitute between products from different countries. Conceptually, Melitz provides a more attractive approach in which substitution is between products from different firms rather than countries. Other attractive features of Melitz are monopolistic competition and economies of scale from fixed establishment costs for firms and fixed set-up costs on trade links. In this paper, we show how, with little change to existing code, an Armington model can be converted to Melitz by adding a few equations and introducing closure swaps. We apply our Armington-to-Melitz method to the Armington-based Global Trade Analysis Project (GTAP) model to derive GTAP-Armington-to-Melitz (GTAP-A2M). We show how results from a CGE model with Melitz industries can be interpreted via back-of-the-envelope calculations. In simulations of the effects of a tariff imposed by North America on imports of apparel, we find greater welfare losses for exporting regions under Melitz than under Armington principally because contraction of apparel output in these regions under Melitz generates an increase in the cost to their households of domestic apparel. Finally, we review two other Melitz-based versions of GTAP: GTAP-HET and a recently published model by Bekkers and Francois.","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48930596","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}
We estimate international transportation margin shares by mode of transport for the Global Trade Analysis Project (GTAP) Data Base. For each available origin-destination-GTAP sector triplet, we estimate the fractional share of the transport margin attributable to air, water, and other shipping modes. We use published relationships between ad valorem proportional changes in prices due to transportation costs and distances, weight-value ratios and fuel prices. Our final database contains 344,554 observations (origin-destination-sector-mode combinations) with transportation margin modal shares organized by 228 exporter countries, 209 importer countries, 45 traded GTAP sectors and 3 transportation modes. The main contribution of this article is to bring a more comprehensive set of information on trade by transport mode covering around 65% of global trade in 2004 and 55% in 2011. Our estimated shares contrast with those traditionally used in the GTAP Data Base which are extrapolations based solely on the modes of transport used by US exporters. A comparison of our shares with those used in version 9.0 of the GTAP Data Base reveals that the role of water transportation services in international trade is underestimated, while that of air transportation is overestimated. Overall, we find that estimations using the modal shares in version 9.0 of the GTAP Data Base overestimate the greenhouse gas emissions associated with international transport. Our new data were used to estimate transport margins by mode in Version 9.1 of the GTAP Data Base, and it is expected that our methods will be used to update future versions of the database.
{"title":"Estimating International Trade Margins Shares by Mode of Transport for the GTAP Data Base","authors":"José G. Nuño‐Ledesma, Nelson B. Villoria","doi":"10.21642/JGEA.040102AF","DOIUrl":"https://doi.org/10.21642/JGEA.040102AF","url":null,"abstract":"We estimate international transportation margin shares by mode of transport for the Global Trade Analysis Project (GTAP) Data Base. For each available origin-destination-GTAP sector triplet, we estimate the fractional share of the transport margin attributable to air, water, and other shipping modes. We use published relationships between ad valorem proportional changes in prices due to transportation costs and distances, weight-value ratios and fuel prices. Our final database contains 344,554 observations (origin-destination-sector-mode combinations) with transportation margin modal shares organized by 228 exporter countries, 209 importer countries, 45 traded GTAP sectors and 3 transportation modes. The main contribution of this article is to bring a more comprehensive set of information on trade by transport mode covering around 65% of global trade in 2004 and 55% in 2011. Our estimated shares contrast with those traditionally used in the GTAP Data Base which are extrapolations based solely on the modes of transport used by US exporters. A comparison of our shares with those used in version 9.0 of the GTAP Data Base reveals that the role of water transportation services in international trade is underestimated, while that of air transportation is overestimated. Overall, we find that estimations using the modal shares in version 9.0 of the GTAP Data Base overestimate the greenhouse gas emissions associated with international transport. Our new data were used to estimate transport margins by mode in Version 9.1 of the GTAP Data Base, and it is expected that our methods will be used to update future versions of the database.","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42424299","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 introduces the Wisconsin National Data Consortium (WiNDC) framework for producing self-consistent accounts based on publicly available datasets that can be used in sub-national economic equilibrium analysis in the United States. We describe the process used to generate regional social accounting matrices and a calibrated static multi-regional, multi-sectoral computable general equilibrium model conformal with the constructed dataset. As illustration, we show how the core model can be applied for the analysis of energy-environment issues. We use an energy-economy extension of the core model to assess the effectiveness of several state level greenhouse gas mitigation proposals. Sub-national abatement measures result in carbon leakage - mandated reductions in controlled areas may be vitiated by increased emissions in uncontrolled jurisdictions. Using a WiNDC-based model, we calculate leakage rates and show how these depend on the underlying trade model. Our calculations demonstrate the importance of both data and modeling assumptions for the simulation of policy experiments.
{"title":"Tools for Open Source, Subnational CGE Modeling with an Illustrative Analysis of Carbon Leakage.","authors":"Thomas F Rutherford, Andrew Schreiber","doi":"10.21642/jgea.040201af","DOIUrl":"https://doi.org/10.21642/jgea.040201af","url":null,"abstract":"<p><p>This paper introduces the Wisconsin National Data Consortium (WiNDC) framework for producing self-consistent accounts based on publicly available datasets that can be used in sub-national economic equilibrium analysis in the United States. We describe the process used to generate regional social accounting matrices and a calibrated static multi-regional, multi-sectoral computable general equilibrium model conformal with the constructed dataset. As illustration, we show how the core model can be applied for the analysis of energy-environment issues. We use an energy-economy extension of the core model to assess the effectiveness of several state level greenhouse gas mitigation proposals. Sub-national abatement measures result in carbon leakage - mandated reductions in controlled areas may be vitiated by increased emissions in uncontrolled jurisdictions. Using a WiNDC-based model, we calculate leakage rates and show how these depend on the underlying trade model. Our calculations demonstrate the importance of both data and modeling assumptions for the simulation of policy experiments.</p>","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":"4 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7266100/pdf/nihms-1563165.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38005899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-27DOI: 10.21642/JGEA.030203SM1F
W. Britz, D. Mensbrugghe
{"title":"CGEBox: A Flexible, Modular and Extendable Framework for CGE Analysis in GAMS (supplemental files)","authors":"W. Britz, D. Mensbrugghe","doi":"10.21642/JGEA.030203SM1F","DOIUrl":"https://doi.org/10.21642/JGEA.030203SM1F","url":null,"abstract":"","PeriodicalId":44607,"journal":{"name":"Journal of Global Economic Analysis","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2018-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48001147","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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