An economic free lunch from marine reserves?

Debate over the consequences of marine reserve implementation has long focused on tradeoffs between ecological improvements from reserves and possible economic losses from reduced harvest. More recently, several articles suggest instead that reserves might generate economic as well as ecological benefits (1; 2; 3; 4). In particular Hastings and Botsford demonstrate that, even without any ecological benefits, a system of marine reserves can generate the same overall fishery yield as traditional quota-based management. This striking result seems to suggest that under simple conditions marine reserves provide an economic free lunch, achieving conservation objectives while leaving fishermen at least as well off as under traditional quota management. The Hastings and Botsford paper is one example within a growing literature that has focused on yield as a measure of the economic health of the system (see (5; 6; 7; 8)). But to capture the economic benefits of a fishery, the critical measure is not the level of