Intact ecosystems provide important global services.
Many valuable ecosystems are located in low-income countries in which citizens are not in a position to provide global public goods gratis . To address this problem, international conservation and development donors have been making substantial investments in habitat conservation. Among the more common conservation schemes are interventions aimed at encouraging commercial activities that produce ecosystem services as joint products. We argue that it would be more cost-effective to pay for conservation performance directly . We use a simple yet general model to establish three conclusions.