Simulation Models of Economic, Demographic, and Environmental Interactions: Are They on a Sustainable Development Path?

One of the most important challenges facing mankind today is the formulation of strategies for sustainable development. These are strategies that could reduce poverty in the current generation, without making development more difficult in the future. One response to this challenge has been the creation at IIASA of a simulation model of development, population, and the environment on Mauritius. The main purpose of this paper is to put the IIASA Mauritius model into perspective by (1) comparing it with other simulation models that include environmental considerations, and (2) showing how these models contribute to the debate about economic, environmental, and demographic interactions. In addition to the IIASA Mauritius model, four others are considered in this paper. The first, the Wonderland Model, is used to introduce essential modeling concepts. The second, World3, is the basis of the books "The Limits to Growth" (1972) and "Beyond the Limits" (1992), and undoubtedly the most famous and most criticized model of sustainable development ever published. The World3 model suggests the likelihood of a dreadful environmental collapse within the next eighty years if population growth and economic growth do not soon come to an end. The third, a model of the Sahel model by Anthony Picardi, appeared as an MIT PhD dissertation in 1974 and is still one of the best pieces of work ever done in the area. It deals with, among other things, an actual environmental collapse that occurred in the Sahel in the early 1970s. The last is the POMA model of population and environment in Costa Rica in 1990. It is a simple framework that takes the environment into account, but does not allow any feedbacks from the environment to the economy. Each of the four teaches us lessons that are used to broaden our understanding the IIASA Mauritius model. The debate on demographic, environmental, and economic interactions has, in many instances, been an acrimonious one with people maintaining that economic growth and population growth must soon come to an end or an environmental catastrophe is imminent, that more rapid economic growth is the key to reducing both environmental degradation and population growth, and that reduced population growth is the key to more rapid economic growth and reduced probabilities of environmental collapse. The models reviewed here are used as frameworks within which to address these conflicting viewpoints. Models of environmental, demographic, and economic interactions have had frightfully short lifetimes and, typically, no descendants. One of the most important challenges facing those interested in these interactions today is the development of strategies of sustainable modeling