In this paper, one of the basic assumptions is that the environment provides two different kinds of services. First, the environment may serve as an input to the production of conventional goods. For example, the exploitation of an oil source from which one firm extracts the oil which in turn is used as a fossil fuel for an industry. In the worst case, the use of the environment for industrial purposes will negatively affect the environment, e.g. the water quality of a paper mill along a river.