This paper assesses the economic impacts of linking the EU emissions trading scheme (ETS) to emerging schemes beyond Europe in the presence of a post-Kyoto agreement in 2020. Numerical simulations with a multi-country equilibrium model of the global carbon market show that linking the European ETS induces only minor economic benefits. As trading is restricted to energy-intensive companies that are assigned high initial emissions, the major compliance burden is carried by the non-trading industries excluded from the linked ETS. In the presence of parallel government trading under a post-Kyoto Protocol, the burden of the excluded sectors can be substantially alleviated by international pen-nit trade at the country level. However, the parallel carbon markets of linked ETS companies and post-Kyoto governments are still separated here. From an efficiency perspective, the most desirable future climate policy regime is thus represented by a joint trading system facilitating international emissions trading between ETS companies and post-Kyoto governments. While the Clean Development Mechanism is not able to attenuate the inefficiencies within linked ETS, in a parallel or joint trading regime the economy-wide access to project-based abatement options in developing countries induces large additional cost-savings. (C) 2007 Elsevier B.V. All rights reserved.
