In 1975 the United States Environmental Protection Agency initiated an historic process of regulatory reform, now known as the Emissions Trading Program. For nonuniformly-mixed pollutants, such as sulfur dioxides, air quality is a function not only of the level of emissions, but their location...

The authors consider a common-property resource sold in imperfectly competitive markets. There is a dynamic externality (current harvests lower future stocks, raising future harvest costs) and a static (crowding) externality. Increasing industry size raises costs but lowers prices; thus, it has...