Economic analyses of climate change policies frequently focus on reductions of energy-related carbon dioxide emissions via market-based, economywide policies. The current course of environment and energy policy debate in the United States, however, suggests an alternative outcome: inefficiently designed and/or sector-based policies. This paper uses a collection of specialized, sector-based models in conjunction with a computable general equilibrium model of the economy to examine and compare these policies at an aggregate level. We examine the relative cost of different policies designed to achieve the same quantity of emissions reductions. We find that excluding a limited number of sectors from an economywide policy does not significantly raise costs. Focusing policy solely on the electricity and transportation sectors doubles costs, however, and using nonmarket policies can raise costs by a factor of 10. These results are driven in part by, and are sensitive to, our modeling of preexisting tax distortions.