General Equilibrium Model of Zebra Mussel Invasion into the Western United States

EPA Grant Number: F6C61448
Title: General Equilibrium Model of Zebra Mussel Invasion into the Western United States
Investigators: Warziniack, Travis
Institution: University of Wyoming
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2006 through September 1, 2009
Project Amount: $98,657
RFA: GRO Fellowships for Graduate Environmental Study (2006) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Environmental Justice , Fellowship - Economics


The spread of invasive species requires innovative modeling techniques. General equilibrium models with biological feedback have yet to adequately model the migration of species between ecosystems and the probabilistic nature of such an invasion. This is an important omission since modeling invasive species implicitly assume such migrations.

This project begins by developing these general techniques and then uses them to analyze work being done by the 100th Meridian Initiative, a joint effort of federal, state, and local governments to prevent the spread of zebra mussels into the Western United States. This includes the Colorado, Columbia, and Sacramento-San Joaquin river systems.


The first stage of the project calculates the direct costs that a zebra mussel invasion would impose on economic sectors in the Western United States. A multi-sector computable general equilibrium model is then built in GAMS (General Algebraic Modeling System) to estimate the welfare effects on households. Sensitivity analyses are done with Monte Carlo simulations over several distribution scenarios for each of the direct cost impacts. Once the static effects are fully understood, a dynamic version of the model can be built that will allow policy makers to focus on the timing of prevention and control methods.

Expected Results:

Two main results are expected to come out of this work:

  1. New modeling techniques will need to be developed to capture the probabilistic nature of an invasion, the biological feedbacks in the system, and the use of dynamic policy tools. To date, little has been done in any of these areas.
  2. This project is part of a larger collaboration that will provide the first quantitative estimates of the value of the 100th Meridian Initiative. More importantly, by explicitly modeling alternative prevention and control strategies—both their cost and effectiveness—this project will provide specific guidance on the level of investments in different prevention programs that would be prudent to protect the economy and aquatic environment of the western US. In the absence of such specific analyses, investments in 100th Meridian efforts have been inadequate, leaving large portions of the western economy and environment largely unprotected from zebra mussel.

Supplemental Keywords:

invasive species, non-native species, computable general equilibrium, dynamic CGE, zebra mussel, 100th Meridian Initiative,, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Monitoring/Modeling, Environmental Monitoring, biodiversity, migratory patterns, general equilibrium model, general algebraic modeling system

Progress and Final Reports:

  • 2007
  • 2008
  • Final