Formulating and Solving Nonlinear Integrated Ecological-Economic Models Using GAMS.

In order to analyze, understand and prescribe natural resource management strategies, the decision making framework should ideally capture the dynamics of inter-dependency between the economic and ecological systems in an integrated manner. However, by including two complex systems within a single integrated framework makes many of the present analytical tools redundant. Computational models on the other hand are ideally suited to meet this challenge. The size and complexity of models solved through numerical techniques have increased exponentially over the last decade. This is especially true for non-linear optimization models. However, although the science of solving non-linear models has improved significantly, the solving of these models is still an art. In this paper, we look at the critical parameters that a modeler needs to be aware of when developing integrated economic-ecology models and some "tricks" to solve them with the minimum of effort through the use of the optimization software GAMS (General Algebraic Modeling System). Copyright 2001 by Kluwer Academic Publishers