Aging populations in advanced economies are placing ever-increasing demands on government spending in the form of old-age benefits. Economies that have promised substantially more benefits than they have made provision to finance are heading into a prolonged era of fiscal stress. Unresolved...

The challenge of mitigating climate change has focused recent attention on basic scientific research feeding into the development of new energy technologies (Popp, 2017). Energy innovation tends to consist of a series of partially overlapping processes involving: (1) the production of scientific...

Greater use of renewable energy is seen as a key component of any move to combat climate change, and is being aggressively promoted as such by the new U.S. administration and by other governments. Yet there is little economic analysis of renewable energy. This paper surveys what is written and...

Generating electricity from renewable sources is more expensive than conventional approaches, but reduces pollution externalities. Analyzing the tradeoff is much more challenging than often presumed, because the value of electricity is extremely dependent on the time and location at which it is...

We study how the implementation of emissions trading systems (ETS) impacts emissions reductions and the usage of renewable energy using a panel sample of the largest 100 countries worldwide. Exploiting the cross-country variations in ETS implementations, we show that ETS adoption materially...

We provide the planner's solution to a model where households learn from exogenous natural disaster arrivals about arrival rates and spend to mitigate future damages. Mitigation cannot be decentralized due to positive externalities from curtailing aggregate risks. First-best can be implemented...

International environment and development agencies increasingly emphasize external cofinancing when selecting projects to fund. This paper considers whether the emphasis on cofinancing helps promote institutional objectives, or creates perverse and inefficient incentives. We present a model of...

We view sustainability as a requirement that welfare should not be expected to decline over time. We impose this requirement as a prior constraint on the consumption-savings-investment problem, and study its implications for saving, risky investment, and the social discount rate. The constraint...