We develop the concept of aggregate emission targets, which are goals for national emissions but do not dictate the forms of regulation used to achieve the goals. We compare aggregate emission intensity, quantity, and price targets adopted at the national level but implemented cost effectively...

We compare the instantaneous and the long run effects of environmental reform in closed and open economies. Harmonization upward (decreasing distortions where they are most severe) or harmonization downward (increasing distortions where they are less severe), both tend to increase instantaneous...

We compare the effects of environmental reform and harmonization in the short and the long run, under autarky and free trade. With trade, harmonization of policies, even if achieved by lowering standards in one country, can improve short run aggregate welfare and increase the likelihood of...