It is widely accepted that one of the most important characteristics of an effective pollution control policy is to provide firms with credible incentives to make long-run investments in R&D that can drastically reduce pollution. Recognizing that a government may be tempted to revise its policy...

Borrowing from the bundling literature, the paper presents a novel model of vertical and horizontal differentiation applied to transport decisions: households differ in their preferences for transportation modes — cars vs public transport — and in the amount of travel. Using few observables,...