The incorporation of an economic input to the evaluation of the potential outcome of scientific research work is a relatively new development in New Zealand. This Research Report presents an analysis of the possible effect a research programme output may have on the New Zealand agricultural scene. The possible outcomes have been quantified and an estimation of the value of those outcomes has been provided. This can be used in an assessment of whether work should proceed on the research project, both in terms of the possible outcome values and the costs yet to be incurred carrying out the research. The objective of this report is to estimate the benefits and costs to New Zealand if agents were introduced to naturally regulate gorse. The costs of gorse include both the direct costs of control and indirect costs in the form of the opportunity cost of lost production.