We consider environmental regulation in a context where firms invest in abatement technology under conditions of uncertainty about subsequent abatement cost, but can subsequently adjust output in the light of true marginal abatement cost. Where an emission tax is the only available instrument,...

We study (energy) markets with dirty incumbents and costly entry by clean producers. For intermediate entry costs, the market outcome exhibits inefficient production and inefficient entry. A policy mix of three popular regulatory instruments—taxation on polluters, feed-in tariffs for clean...

Much of the literature on externalities has considered taxes and direct regulation as alternative policy instruments. Both instruments may in practice be imperfect, reflecting informational deficiencies and other limitations. We analyse the use of taxes and regulation in combination, to control...