Tradable permits are celebrated as a political instrument since they allow (i) firms to equalize marginal abatement costs through trade and (ii) the government to distribute the burden of the policy in a politically fair and feasible way. These two concerns, however, conflict in a dynamic...

Pigou's conjecture was that under costly taxation public expenditures should not reach the point where marginal benefits equal marginal costs. In the treatment here, public expenditures (and environmental protection) may provide public goods for consumption but also collective inputs for...