"The central challenge of tropical biodiversity conservation involves reconciling private and social incentives to 'internalize' externalities. Positive externalities of natural resource conservation accrue at the local, national and global levels, although the costs of conservation are...

"In 1968, Hardin argued that all commonly-owned resources would tragically be depleted unless private ownership was granted. There are many case studies which prove Hardin wrong. Common-pool resources have been managed with success. However, this success does not imply (as some believe) that...