Price discovery and intermediation in linked emissions trading markets: A laboratory study

Many new and proposed emissions trading systems involve multiple countries and regions. The introduction of interregional trading raises questions about how flexible state- or national-level authorities should be in allowing individual firms to trade with firms or authorities in other states or countries. This paper uses laboratory methods to evaluate the efficiency and pricing performance of linking trading across regions at the firm-to-firm level. In one treatment, individual firms trade directly with firms or authorities in other regions. We compare performance in this treatment to an intergovernmental trading treatment, where emissions trading is restricted to occur only between intermediaries. A baseline treatment of autarky, where firms only trade with other firms in their country or region, provides a benchmark to assess the efficiency benefits of allowing linking. Although efficiency and price discovery are both improved by allowing intermediation in linked permit markets, we find that further gains can be realized through direct firm to firm trading. Buyers in high cost regions and sellers in low cost regions benefit the greatest from linking.