Given the coexistent EU priorities concerning the competitiveness of European industries and international emissions regulation at the company level, this paper assesses the efficiency and competitiveness implications of linking the EU Emissions Trading Scheme (ETS) to emerging trading schemes outside Europe. Currently, countries like Canada, Japan or Australia are contemplating the set up of domestic ETS with the intention of linking up to the European scheme. While a stylized partial-market analysis suggests that the integration of trading systems is always beneficial in efficiency terms, our applied general equilibrium approach shows that the aggregate welfare impacts of linking the EU ETS are rather limited. We further find that the tra...