Economics Study Shows Risk Assessment of Potentially Invasive Animal Species Pays Off

Findings demonstrate substantial returns on screening program relative to current costs of open-door policy

WASHINGTON, Aug. 15, 2011 — In a major new study published in the journal Ecological Economics, scientists and economists have, for the first time, statistically demonstrated the net benefits of doing risk assessments for the live wild animal trade. The study estimates that the long-term expected net benefits from implementing a risk screening system range from approximately $54,000 to $150,000 per species assessed, assuming typical import scenarios and mid-range impacts of non-native reptiles and amphibians.

The federal government has come under sharp criticism for allowing invasive animal species into the country, which have caused major damages to the environment and agriculture, leading to economic costs and environmental and safety risks. Recent invasions by imported animal species such as the Burmese python, Asian carp, and red lionfish are together costing federal, state and local governments tens of millions of dollars annually in efforts to control them. These costs could have been avoided if authorities had considered their risks beforehand and restricted their importation.

“Managing the introduction of non-indigenous species is becoming a major goal of policy makers,” said the lead author of the study, Michael Springborn, Ph.D., of the University of California at Davis. “How do we as a nation balance the benefits of trade against the risk of invasive species establishment? Our study integrated biology and economics to tackle that question.”

As a leading import market, the United States receives hundreds of millions of non-native animals each year, which represent thousands of different wildlife species. In practice, very few risk assessments are done, and the Lacey Act, the 111-year-old law that governs the wildlife trade, has only 25 entries on the restricted “injurious species” list. These species were typically restricted only after years of importation, and damage had already occurred. In contrast, Australia, New Zealand, and Israel require all new animal species to be assessed for the likelihood of invasion before they are allowed into those countries.

“Using over a decade of data on reptiles and amphibians imported to the United States as a case study, we described economic outcomes over a range of scenarios and demonstrated benefits of a risk screening program compared to our current basically ‘open-door’ policy,” said co-author Christina Romagosa, Ph.D., of Auburn University.

The results add to the published literature showing that preventing the import of particularly risky species is preferable economically to allowing the trade and suffering the consequences of establishment.

“While we knew from a prior study that risk screening for the plant import trade leads to large economic and environmental benefits, this is the first paper to show comparable benefits for the live animal trade, which is huge in this country,” said co-author Reuben Keller, Ph.D., of the University of Chicago.

For several years, Congress has considered bills mandating stricter risk assessment procedures, but the legislation has stalled. Currently, Senator Bill Nelson of Florida is promoting the Invasive Wildlife Prevention Act to modernize the Lacey Act injurious species listing process.

“The old saying ‘an ounce of prevention is worth a pound of cure’ was ahead of its time when it comes to invasive species policy,” said Peter Jenkins, spokesperson for groups in the National Environmental Coalition on Invasive Species, which is working with members of Congress to modernize the Lacey Act. “This economics study provides Congress with strong financial justification to adopt a thorough risk assessment approach for live animal imports coming into this country.”

The study is: Springborn, M., Romagosa, C.M., Keller, R.P., The value of non-indigenous species risk assessment in international trade, Ecol. Econ. (2011), doi:10.1016/j.ecolecon.2011.06.016.

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Established in 2003, the National Environmental Coalition on Invasive Species is a national partnership of 17 major conservation and environmental organizations that provides a united expert and scientific voice on invasive species policy. Its leaders include scientists, lawyers, activists and advocates with many years of experience on invasives policy. For more information, please visit