Biological Invasions and International Trade: Managing a Moving Target

Humans move species around the globe, both intentionally and unintentionally, and biological invasions have been accelerating for many species groups (Seebens et al. 2017). While most nonnative species (NNS) have little impact within their invaded habitat, many exhibit extraordinary population growth and adversely affect species with which they share no evolutionary history.1 NNS can also have significant negative economic impacts, estimated at $162 billion ($2019) annually in the United States (Pimentel, Zuniga, and Morrison 2005) and up to 12 percent of GDP in some developed countries (Marbuah, Gren, and McKie 2014). Harmful impacts of NNS include disrupting agriculture and other managed landscapes (e.g., forests, aquatic systems), ecosystem service loss, and disease spread (Eiswerth, Lawley, and Taylor 2018). For example, the emerald ash borer beetle—likely introduced to the United States via wood packaging material—has spread to at least 35 states, killing hundreds of millions of ash trees. Its impacts on US residential housing values alone are estimated at $452 million ($2019) annually (Aukema et al. 2011), with total discounted damages of $24.9 billion ($2019; Epanchin-Niell and Liebhold 2015).

In this article, we examine the processes underlying the relationship between trade and NNS, interventions aimed at preventing NNS introductions, and the role of policy and economic research in managing and reducing trade-related NNS risk.2 We begin by describing factors and processes affecting the introduction of NNS through trade. Then we discuss how economics helps to quantify NNS impacts, elucidate the dynamics of trade and NNS risk, and inform biosecurity interventions. Finally, we outline future priorities for economic research and policy.