A note on the economics of biological invasions

Despite the rising concern over the economic costs of biological invasions, no general modelling approach of these costs has been developed. The purpo se of this note is to develop such a framework, and to demonstrate how conv entional bioeconomic models of interspecific competition, such as the preda tor-prey model, are essentially special cases. A model of the economic cons equences of the biological invasion must therefore be based on two principl es. First, the economic impacts imposed by the invader will depend on the e xact nature of the interspecific interaction, and secondly, the correct mea sure of these impacts should be based on a comparison of the ex post and ex ante invasion scenarios. An important consideration is determining whether the spread, or dispersal, of the invading species in turn affects the loca tion and movement of the resident species in the pre-existing habitat, or w hether the interspecific competition occurs solely in the same habitat area without diffusive movement of either species, or finally, whether both spe cies dispersal and some form of interspecific competition might occur as a result of an invasion. (C) 2001 Elsevier Science B.V. All rights reserved.