Chapter 11: Public Goods and Common Resources

Excludability refers to the ability to prevent people from using a good, while rivalry describes whether one person's consumption diminishes what remains available for others. These dimensions create four distinct categories: private goods are both excludable and rival, public goods are neither excludable nor rival, common resources are rival but not excludable, and club goods are excludable but not rival. Public goods such as national defense, fireworks displays, and basic scientific research create a free-rider problem because individuals can benefit without contributing financially, causing private markets to undersupply them significantly below socially optimal levels. Governments address this market failure through taxation and cost-benefit analysis, though determining monetary values for intangible outcomes like safety and human life remains methodologically challenging. The chapter illustrates these concepts through case studies including lighthouses, which have shifted between public and private provision depending on institutional circumstances. Common resources present the opposite problem: because they are rival but not excludable, individuals have little incentive to conserve them, leading to the Tragedy of the Commons. When collective resources like grazing lands, fisheries, or environmental assets lack clear ownership, users pursue self-interest without internalizing the costs they impose on others, resulting in systematic overuse and depletion. Modern examples include air and water pollution, traffic congestion, and overfishing in international waters. Solutions involve government intervention through regulations, corrective taxation, tradeable permits, or the assignment of property rights that convert common resources into private goods with defined ownership. Comparative examples of elephants versus cattle demonstrate how institutional frameworks and property rights structures fundamentally shape conservation outcomes and resource sustainability. The chapter concludes that well-functioning markets require clearly defined and enforceable property rights; when these conditions do not exist, collective action through government policy or community management becomes essential for preventing resource degradation and achieving economic efficiency.