Commodity price increases associated with the entry of China, India, and other countries into the world economy have led to increased pressure on common-property renewable natural resources. The problem is particularly worrisome for economies that obtain a large share of their income from the...

Optimal harvesting of prey in a predator–prey ecosystem is studied under the condition that the existence of the predator has value. Predators (birds) and humans (fishers) compete for prey (shellfish). The behavior of the system is studied and conditions for optimal control are deduced....