Capital Malleability, Emission Leakage and the Cost of Partial Climate Policies: General Equilibrium Analysis of the European Union Emission Trading System

Computable general equilibrium (CGE) models are the premier analytical platform for assessing the economic impacts of climate change mitigation. But these models tend to treat physical capital as “malleable”, capable of reallocation among sectors over the time-period for which equilibrium is solved. Because the extent to which capital adjustment costs might dampen reallocation is not well understood, there is concern that CGE assessments understate the true costs of greenhouse gas (GHG) reduction policies. This paper uses a multi-region, multi-sector CGE model to investigate cap-and-trade schemes, such as the European Union Emission Trading System which cover a subset of the economy, elucidating the effects of capital malleability on GHG abatement, the potential for emission leakage from abating to non-abating sectors, and the impacts on welfare. To simplify the complex interactions being simulated within the CGE model, that analysis is complemented with an analytical model. A partial climate policy results in negative internal carbon leakage, with emissions declining not only in capped sectors but also in non-regulated ones. This result is stronger when capital is intersectorally mobile. Interestingly, in partial climate policy settings capital malleability can amplify or attenuate welfare losses depending on the attributes of the economy.