The D4 RIN is the tradable compliance certificate for the biomass-based diesel mandate in the Renewable Fuel Standard (RFS). Understanding the price dynamics of the D4 RIN is important for understanding the RFS because its price sets a ceiling on the ethanol RIN (D6) and because some observers...

The U.S. tax code provides a number of subsidies for low-carbon technologies. I discuss the difficulties of achieving key policy goals with subsidies as opposed to using taxes to raise the price of pollution-related activities. In particular, subsidies lower the cost of energy (on average)...

In a market subject to environmental regulation, a firmamp;apos;s strategic behavior affects the production and emissions decisions of all firms. If firms are regulated by a Pigouvian tax, changing emissions will not affect the marginal cost of polluting. However, under a tradable permits...

I generalize a benchmark model of directed technical change to allow innovations and factors of production (here energy resources) to be substitutes or complements. I show that a dominant sector is forever locked-in under substitutability but researchers' market incentives can drive a transition...

Flexibility in environmental regulations can lead to reduced costs if it allows additional abatement from lower cost sources or if policy tailoring and experimentation across states increases regulatory efficiency. The EPA's 2014 Clean Power Plan, which implements greenhouse gas regulation of...

What induces clean energy transitions? When transitional dynamics exhibit strong path dependence, a temporary shock to input composition can trigger permanent structural change. I examine whether such dynamics characterize the U.S. electricity sector's use of coal - the most climate-damaging...

Economists have tended to view cap and trade (or, more generally, emissions pricing) as more cost-effective than a clean energy standard (CES) for the purpose of reducing greenhouse gas emissions associated with electricity generation. This stems in part from the finding that, in terms of...

To reliably achieve deep decarbonization of the US power sector, a candidate policy must perform robustly across a range of possible future trajectories of demand, fossil fuel prices, and prices of new wind and solar capacity. Using a modified version of the NREL ReEDS model with scenarios that...

We develop a microeconomic model of endogenous growth where clean and dirty technologies compete in production and innovation—in the sense that research can be directed to either clean or dirty technologies. If dirty technologies are more advanced to start with, the potential transition to...