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...

Free trade often leads to resource depletion, such as deforestation in the tropics. This paper first presents a dynamic model whereby the South (S) depletes to export the extracted units (lumber) or the produce (beef) from land available after depletion. Because of the damages, the North...

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...

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...

We characterize the optimal policy and policy instruments for self-enforcing treaties when countries invest in green technology before they pollute. If the discount factor is too small to support the first best, then both emissions and investments will be larger than in the first best, when...