The reality of protected area management is that enforcing forest and park boundaries is costly and so most likely incomplete, due in part to the pressures exerted on the boundaries by local people who often have traditionally relied on the park resources. Buffer zones are increasingly being proposed and implemented to protect both forest resources and livelihoods. Developing a spatially-explicit optimal enforcement model, this paper demonstrates that there is a trade-off between the amount spent on enforcement, the size of a formal buffer zone, and the extent to which a forest can be protected from illegal extraction. Indeed, given the reality of limited enforcement budgets, a forest manager with a mandate to protect a whole forest may in fact end up doing a worse job than one who is able to incorporate an appropriately sized buffer zone into their management plans that, combined with more effective enforcement of a smaller exclusion zone, provide the appropriate incentives for villagers to extract only in the periphery of the forest, rather than venture further into the forest.
