You are here:
On the Sustainability and Management of a Model System with Ecological, Macroeconomic, and Legal Components
Citation:
CABEZAS, H. On the Sustainability and Management of a Model System with Ecological, Macroeconomic, and Legal Components. Presented at Institute of Chemical and Engineering Sciences, Jurong Island, SINGAPORE, October 22 - 24, 2007.
Impact/Purpose:
To inform the public
Description:
Sustainability is essentially about insuring that human existence can be indefinitely supported by the biological system of the Earth at an appropriate level of civilization. Hence, one of the most fundamental questions in sustainability is the extent to which human activities and decision making are compatible with the goal of sustainability. This is a fundamental policy question. To explore this question, a model system was constructed encompassing a biological food web, a rudimentary legal system regulating rights to two biological species (a plant and a herbivore) designated as private property, a price-setting macro-economic system controlling the trading of goods and labor. There is also an abstract industrial process that simply uses mass from a private property plant and a freely available resource, e.g. air, to manufacture a product which humans value and are willing to purchase. All mass passing through the industrial process eventually becomes mass which is biologically unavailable over the short term. A mathematical model embodying these principles was constructed, and computer simulations of the behavior of the system were conducted under various scenarios. Three broad classes of scenarios were explored: (1) economic decision making aims to maximize human welfare in the immediate future with no regard for the value of environmental preservation, (2) economic decision making that maximizes human well-being subject to fee on waste and a law limiting access by the private property herbivore to protected wild plants, and (3) economic decision making that maximizes human well-being subject to an active optimal control system that manipulates the fee on waste and the access by the private property herbivore to protected wild plants with the goal of minimizing fluctuations in the Fisher information of the system averaged over a time bracket. The form of Fisher information used here is a measure of dynamic order. Because all well functioning biological and social systems are highly ordered systems where order is often lost when the system malfunctions, it is legitimate to use as a control goal the minimization of fluctuations in the averaged Fisher information. It should be noted that the first broad class of scenarios often resulted in the cataclysmic loss of biological species and often completely dead systems. The second broad category of scenarios yielded viable systems as long as the human population was not growing and the per capita consumption of resources was not increasing. However, under either an increasing human population or an increasing per capita consumption of resources, the system did eventually collapse. The optimal control process in the third broad class of scenarios was successful in delaying but not eliminating the difficulties brought about by an increasing human population which is consuming ever more resources. Lastly, it should be noted that changes in the Fisher information often preceded system wide collapses. While these results may not seem entirely too surprising, it is important establish that they seem to hold in principle under fairly general conditions.