Biological pollution prevention strategies under ignorance: The case of invasive species

Invasive alien species (IAS)-species that establish and spread in ecosystems to that they are not native-are argued to be the second-most important cause of biodiversity loss worldwide. Without natural predators, parasites, and/or pathogens to help control population growth, IAS frequently out-compete or prey on native species. They cause or spread diseases to cultivated plants, livestock and human populations. They often encroach on, damage or degrade assets (e.g., power plants, boats, piers, and reservoirs). The associated economic impacts can be significant. In this article, we examine the IAS preinvasion control problem using both ignorance and risk-management models. We begin with the more familiar risk-management framework, which might be advocated in the special case of full information. Next, we proceed using an ignorance (or uncertainty) framework. We indicate the information required to develop such a model, and we illustrate that rational policy design is possible under ignorance. Finally, we make qualitative comparisons between the two approaches.