The project enhances the U.S. Regional Energy Policy (USREP) model that identifies states and multi-state regions in the US. The models project economic variables (GDP, energy use, sectoral output, consumption, etc.) and emissions of greenhouse gases (CO₂, CH₄, N₂O, HFCs, PFCs and SF₆) and other air pollutants (CO, VOC, NOx, SO₂, NH₃, black carbon, and organic carbon) from combustion of carbon-based fuels, industrial processes, waste handling, and agricultural activities in sectors throughout the economy. The state-level database provides the flexibility to create different regional aggregations down to individual states appropriate for the question to be addressed, and there is also detail to consider effects by income levels.