doi:10.1017/S1355770X06003044 Printed in the United Kingdom The bioeconomics of controlling an African rodent pest species

ABSTRACT. The paper treats the economy of controlling an African pest rodent, the multimammate rat, causing major damage in maize production. An ecological population model is presented and used as a basis for the economic analyses carried out at the village level using data from Tanzania. This model incorporates both density-dependent and density-independent (stochastic) factors. Rodents are controlled by applying poison, and the costs are made up of the cost of poison plus the damage to maize production. We analyse how the present-value costs of maize production are affected by various ∗Corresponding author We thank the late Patrick Mwanjabe for several valuable discussions on the pest problem treated in this paper and three referees for valuable comments. AS thanks for support from theNorwegian ScienceCouncil.NCS andHPA thank for valuable support from University of Oslo and the Norwegian Science Council. NCS and HL appreciate the EU-support through the STAPLERAT project (ICA4-CT-2000-30029) and the Danish Council for Development Research (RUF). LSM appreciates the support from the SUA-VLIR program