Chapter 10 Modeling languages in computational economics: Gams

A GAMS model is a collection of statements in the GAMS language that define the variables of the model, specify the symbolic relationships among them in the form of equations, specify data structures and assign values to them, and instructs the computer to generate and solve the model. This chapter provides an introduction to algebraic modeling language, general algebraic modeling system (GAMS) of Brooke, Kendrick and Meeraus (1992). The chapter also gives an overview of the language and illustrates its use in modeling problems in transportation, asset allocation, and the estimation of social accounting matrices. This system provides a high-level (algebraic) language for the representation of large and complex models. It allows for unambiguous statements of algebraic relations that define an abstract system of variables and equations. It also provides mechanisms for data management. The system performs appropriate data transformations to create a specific instance of the model, starting from the abstract representation. Because, the model description is algebraic the GAMS statement of the model provides a readable documentation. The data management mechanisms also facilitate the preparation of reports.