Alex and Belle are both loggers who want to harvest timber from the same forest. Alex prefers to harvest and replant at a sustainable rate; Belle wants to harvest as many trees as possible to maximize short-run profit and then move on. They face the same production costs. If property rights are poorly enforced or nonexistent, Belle will choose to harvest as quickly as possible, but Alex will choose to harvest more slowly and replant. both will harvest trees as quickly as possible, before the other one does. both now have an incentive to harvest and replant in a sustainable manner. they would be expected to form an agreement on harvesting and replanting