the government could impose restrictions on access to wood in the forest. Right! Private good A good that is both rival and excludable. Public good A good that is both nonrivalrous and nonexcludable. ​Quasi-public good A good that is excludable but not rival. Common resource A good that is rival but not excludable. The source of the overuse of common resources is the same as the source of negative​ externalities: lack of clearly defined and enforced property rights. In situations in which enforcing property rights is not​ feasible, two types of solutions to the overuse of common resources are possible. If the geographic area involved is limited and the number of people involved is​ small, access to the commons can be restricted through community norms and laws​ (limits enforced by social​ pressure). If the geographic area or the number of people involved is​ large, legal restrictions on access to the commons are required​ (taxes, quotas, and tradable​ permits)