I examine a policy-making game among countries that must choose both a policy instrument (e.g., a tax or a quota) and its intensity (i.e., the tax rate or the quota level) to price pollution. When countries price pollution non-cooperatively, they not only set the intensity inefficiently, they...

This paper explores how a principal with time-inconsistent preferences invests optimally in technology or capital. If the current principal prefers her future self to save more, she can increase current investments complementary to future savings and decrease investments in the strategic...

There are often conflicts between proponents of trade and environmental activists. This paper shows, however, how trade agreements can be designed so as to motivate environmental conservation. I first analyze a standard trade model, where resource exploitation (e.g., deforestation) is a...

We analyze a repeated game in which countries are polluting as well as investing in technologies. While folk theorems point out that the first best can be sustained as a subgame-perfect equilibrium when the players are sufficiently patient, we derive the second best equilibrium when they are...

Free-riding is at the core of environmental problems. If a climate coalition reduces its emissions, world prices change and nonparticipants typically emit more; they may also extract the dirtiest type of fossil fuel and invest too little in green technology. The coalition's second-best policy...