SAGE is an applied general equilibrium model of the United States economy developed for the analysis of environmental regulations and policies. It is an intertemporal model with perfect foresight, resolved at the sub-national level. Each of the nine regions in the model, representing the nine census divisions, has ve households based on income quintiles. A single government agent levies taxes on labor earnings, capital earnings, production, and consumption. As with many applied general equilibrium models used for the analysis of U.S. environmental and energy policies, the baseline is calibrated to the Energy Information Administration's Annual Energy Outlook. The model is solved as mixed complementarity problem (MCP) using the General Algebraic Modeling System (GAMS).