Western Economics Forum, April 2004 1 INVASIVE SPECIES IN AGRICULTURE: A RISING CONCERN by Colin A. Carter, James A. Chalfant, and Rachael E. Goodhue Department of Agricultural and Resource Economics University of California, Davis “The Boll Weevil say to the Farmer, You can ride in that Ford machine, But when I get through with your cotton you can't buy gasoline, You won't have no home, won't have no home.” Boll Weevil Song (performed by Carl Sandberg in the 1920s) 1 Invasive species are not new phenomena in U.S. agriculture, as illustrated by these 1920s lyrics from the Boll Weevil folksong. The boll weevil entered the United States via Mexico in the 1890s, and by the 1920s, this pest had spread to all cotton producing states, wiping out tens of thousands of acres of cotton, costing billions of dollars, and literally driving thousands of farmers off the land. There are similar examples in other parts of the world. In the 1860s, an agronomist transferred grape vines from the U.S. to France, to try to improve wine quality, and accidentally introduced phylloxera, a small louse that feeds on the roots of grape vines. As a result, France lost almost 75% of its vines at the time. 2 Despite this history of dealing with invasive species in the United States and elsewhere, many informational gaps remain with regard to optimal policies. The purpose of this article is to provide the reader an introduction to issues concerning invasive species in U.S. agriculture. We explain why invasive species are viewed as a growing concern in the United States, and consider the role of economics. There are two aspects to that role. First, economic factors may influence the introduction, spread, response to, and control of invasive species, and ultimately determine whether an invasion is successful. We also argue that economists have a crucial role to play in terms of analyzing the problem and improving the understanding of the economic impacts of invasive species. Economists can evaluate alternative policy responses to deal with the uncertainty associated with any one of a vast number of potential invaders of specific ecosystems, and the resulting ecological and economic damage. While understanding interactions between species can be done in a purely biological model of an ecosystem, it is economic behavior—beginning with the mode by which the species was introduced, and certainly including patterns of production, marketing, and consumption— that determines how an invasive species affects agricultural industries and, ultimately, policy responses to invasions. We outline the various approaches that economists are taking in their research on invasive species, to incorporate these factors in modeling invasive species in U.S. agriculture. In 2003, the USDA’s Economic Research Service (ERS) instituted a three year competitive grants program aimed at improving the understanding of the economics of invasive species. The ERS program underscores the fact that policy makers realize there are important informational gaps when it comes to dealing with invasive species. Recently, there has been a flurry of legislative action directed at invasive species, at both the state and national level. For instance, in 2004 the California legislature passed a bill (AB2631) that establishes an Invasive Species Council to develop a statewide invasive 1 http://www.simplelife.com/organiccotton/08WEEVLsng.html 2 http://wine.about.com/library/weekly/aa052900.htm