This volume presents six new papers on environmental/energy economics and policy. Robert Stavins evaluates carbon taxes versus a cap-and-trade mechanism for reducing greenhouse-gas emissions, arguing that specific design features of either instrument can be more consequential than the choice of instrument itself. Lucas Davis and James Sallee show that the exemption of electric vehicles from the gasoline tax is likely to be efficient as long as gasoline prices remain below social marginal costs, even though it results in lower tax revenue. Caroline Flammer analyzes the rapidly growing market for green bonds and highlights the importance of third-party certification to the financial and environmental performance of publically traded companies. Antonio Bento, Mark Jacobsen, Christopher Knittel, and Arthur van Benthem develop a general framework for evaluating the costs and benefits of fuel economy standards and use it to account for the differences between several recent studies of changes in these standards. Nicholas Muller estimates a measure of output in the U.S. economy over the last 60 years that accounts for air pollution damages, and shows that pollution effects are sizable, affect growth rates, and have diminished appreciably over time. Finally, Marc Hafstead and Roberton Williams illustrate methods of accounting for employment effects when evaluating the costs and benefits of environmental regulations.