GTAPinGAMS: The Dataset and Static Model

The Global Trade Analysis Project (GTAP) is a research program initiated in 1992 to provide the economic research community with a global economic dataset for use in the quantitative analyses of international economic issues. The Project’s objectives include the provision of a documented, publicly available, global, general equilibrium data base, and to conduct seminars on a regular basis to inform the research community about how to use the data in applied economic analysis. GTAP has lead to the establishment of a global network of researchers who share a common interest of multi-region trade analysis and related issues. The GTAP research program is coordinated by Thomas Hertel, Director of the Center for Global Trade Analysis at Purdue University. As Deputy Director of this Center, Robert McDougall oversees the data base work. Software development within the GTAP project has been assisted greatly by the efforts of Ken Pearson and other Australian researchers from Centre of Policy Studies, Monash University. (See Hertel [1997], McDougall [1998]. A list of applications based on the GTAP framework can be found at the GTAP home page (http://www.agecon.purdue.edu/gtap/apps/).) The standard programming language for GTAP data and modeling work has been GEMPACK (Harrison and Pearson [1996]). In the GEMPACK framework the model is solved as a system of nonlinear equations. The present paper describes a version of the GTAP model which has been implemented as a nonlinear complementarity problem in the GAMS programming language. Along with the core model I have developed several ancillary programs for dataset management. I call the package “GTAPinGAMS”. These programs should be useful to economists who program in GAMS and wish to use GTAP in applied work. These programs include tools for translation of the GTAP files into GAMS readable form, GAMS programs for dataset aggregation, filtering and the imposition of alternative tax rates on trade or domestic transactions. The GTAP version 4 database represents global production and trade for 45 country/regions, 50 commodities and 5 primary factors. The data characterize intermediate demand and bilateral trade in 1995, including tax rates on imports and exports. The core static model described in this paper does not have precisely the same structure as the GTAP model implemented in GEMPACK. There are several immediate differences between the standard GTAP model and the GTAPinGAMS model. First, the units of account are different by a factor of 10000. GTAP mea-