The Program on Energy and Sustainable Development is part of the Freeman Spogli Institute for International Studies.
We report on an economic experiment that compares outcomes in electricity markets subject to carbon-tax and cap-and-trade policies. Under conditions of uncertainty, price-based and quantity-based policy instruments cannot be truly equivalent, so we compared three matched carbon-tax/cap-and-trade pairs with equivalent emissions targets, mean emissions, and mean carbon prices, respectively.
The authors ran a game-based simulation of an electricity market with both an RPS and a cap-and-trade market for greenhouse gas emissions allowances. High renewable energy shares reduced and shifted the output of thermal units and pushed down both electricity and carbon prices. The markets for renewable energy, carbon allowances, and spot and forward electricity interacted in complex ways that are relevant to the behavior of actual markets.