Multiproduct Firms and Environmental Policy Coordination

The literature that analyzes the coordination of environmental taxes by governments considers that firms produce a single good at a single plant. However, in practice firms tend to produce several goods at various production plants (multiproduct firms). These firms may organize themselves in a centralized or decentralized fashion for purposes of decision-making: This affects their output and pollution levels. This paper sets out to analyze the coordination of environmental taxes considering multiproduct firms. We find that the organizational structure chosen by the owners of the firms depends on whether or not governments coordinate with one another in setting taxes, and on whether the goods produced are substitutes or complements. Social welfare is greater if a supranational authority sets taxes in all countries. In this case, joint welfare is never lower if the authority is constrained to set the same tax in all countries.