Renewable portfolio standards (RPS) are commonly promoted as a policy tool to reduce emissions associated with fossil generation, while also stimulating development of local renewable resource endowments. We develop a general equilibrium model of an RPS policy that captures key features such as...

In transportation systems with unpriced congestion, allowing single-occupant low-emission vehicles in high occupancy vehicle (HOV) lanes to encourage their adoption exacerbates congestion costs for carpoolers. The resulting welfare effects of the policy are negative, with environmental benefits...