Environmental Taxation and Redistribution Concerns

How is the optimal level of Pigouvian taxation influenced by distributive concerns? With second-best instruments, a higher level of income redistribution calls for a lower level of Pigouvian taxation. More redistribution implies higher distortions from income taxation. Pigouvian tax revenues become more valuable, and the optimal level of environmental taxation decreases. With first-best instruments, however, the relation between levels of redistribution and Pigouvian taxation is reversed. So second-best Pigouvian taxes are very different from their first-best counterpart --- despite apparently identical first-order conditions.