Cost-benefit analysis of pre-import screening1.

Paper presented at: Preventing biological invasions: best practices in pre-import risk screening for species of live animals in international trade workshop, April 2008. Session 2: Science and economics of pre-import screening for animal species International commerce in live organisms presents a policy challenge for trade globalization: sales of live organisms create wealth, but some nonindigenous species cause harm. In order to reduce damages, some countries have implemented species screening to limit introductions of damaging species. Adoption of new risk assessment technologies has been slowed, however, by concerns that risk assessment accuracy remains insufficient to produce positive net economic benefits. This concern arises because only a small proportion of all introduced species escape, spread, and cause harm (i.e. become invasive), so a risk assessment will exclude many non-invasive species (which provide a net economic benefit) for every invasive species correctly identified. Here, we develop a simple cost:benefit bioeconomic framework to quantify the net benefits from applying species pre-screening. Because invasive species are rarely eradicated and their damages must therefore be borne for long periods, we have projected the value of risk assessment over a suitable range of policy time horizons (10-100 years). We apply the model to the Australian plant quarantine program and show that this risk assessment program produces positive net economic benefits over the range of reasonable assumptions. Because we use low estimates of the financial damage caused by invasive species and high estimates of the value of species in the ornamental trade, our results underestimate the net benefit of the Australian plant quarantine program. In addition, because plants have relatively low rates of invasion, applying screening protocols to animals would likely demonstrate even greater benefits