Computing solutions for large general equilibrium models using GEMPACK

GEMPACK is a suite of general-purpose economic modelling software especially suitable for general and partial equilibrium models. It can handle a wide range of economic behaviour and also contains a versatile method for solving intertemporal models. GEMPACK provides software for calculating accurate solutions of an economic model, starting from an algebraic representation of the equations of the model. These equations can be written as levels equations, linearized equations or a mixture of these two. The software provides a range of utility programs for handling the economic data base and the results of simulations, and is fully documented from a user's point of view. GEMPACK is used to implement and solve a number of economic models including several single-country models (of which the ORANI model of Australia is perhaps the best known), multi-country trade models, regional models and intertemporal (or dynamic) models. GEMPACK runs on a wide variety of computers including 80386/80486 microcomputers running DOS, Windows or OS/2, Apple Macintosh computers, Unix machines, DEC VAX and Alpha machines running VMS. This paper gives an overview of the current release of GEMPACK (Release 5.1, April 1994). Included are descriptions of the algebra-like language used to describe and document the equations of an economic model, the operation of the pre-processor TABLO which converts the equations of the model to a form suitable for computing solutions of the model, the solution methods used for producing accurate solutions of the model, the facilities for specifying and carrying out simulations, including the options for varying the choice of endogenous and exogenous variables and the variables shocked, the condensation facility which makes it possible to solve very large models, the utility programs for assisting in managing the data bases on which models are based, the different versions of GEMPACK.