An Economic Assessment of Biological Control for Miconia calvescens in Hawaii

Biocontrol, the introduction of organisms to control an unwanted species, has been cited as a powerful method to manage the invasive species Miconia calvescens in Hawaii. In addition to ecological advantages, biocontrol is often regarded as less costly than traditional methods despite the large initial investment. Currently, miconia in Hawaii is treated through aerial and manual operations, which cost over $1 million annually. Biocontrol for miconia in Hawaii began in 1997 and the search for more agents continues today. Although biocontrol for miconia has already begun, prior to this study no assessment of its economic justifiability had been done. This research evaluates the present value of net benefits of miconia biocontrol in Hawaii. Cost data were gathered from scientists in charge of biocontrol programs. Benefits were defined as the cost-savings of current control methods. Two different biocontrol programs were modeled: control achieved by a single agent, and control achieved by a suite of agents. In addition, different dispersal rates and efficacies of biocontrol and two release dates were modeled. Because most costs of biocontrol are incurred before the release of a successful agent and the benefits are only realized post-release, each scenario was evaluated over a 50-year time horizon. The results indicate a positive present value of net benefits in all scenarios, ranging from $12.8 million to $36.1 million. Thus, biocontrol for miconia in Hawaii appears to be economically justifiable. This research should enable scientists, economists and policy makers to make informed decisions about the optimal management of Miconia calvescens in Hawaii.