My research focus is at the intersection of environmental and energy economics and public finance, with an emphasis on strategies for designing public policies to curb air pollution and greenhouse gas (GHG) emissions. I have studied the design and implementation of economy-wide and sector-specific abatement policies, and their interactions. Common threads in my research agenda are the study of optimal policy design in the presence of multiple unpriced externalities and heterogeneity of firms’ and households’ responses to environmental policy. These studies can reveal interesting interactions between climate policies and other sources of social cost and benefit, such as the congestion cost of granting solo hybrid vehicle drivers access to carpool lanes, and provide new insights about the efficient design of economic mechanisms. My work helps to uncover new evidence on the nature of firms’ and households’ responses to environmental policy, such as electricity importers’ responses to a GHG pricing regime or households’ responses to gasoline price changes, often shedding light on the unanticipated consequences of existing policy. In addition to my empirical work, I have developed theory models to analyze the impact of lobbying during the regulatory process on allocative-efficiency and rent-seeking. This theory work complements my empirical work on GHG market design.