Market structure and the pricing of electricity and natural gas

US Electricity and natural gas markets have traditionally been serviced by one of two market structures. In some markets, electricity and natural gas are sold by a regulated dual-product monopolist, while in other markets, electricity and natural gas are sold by separate regulated single-product monopolies. I analyze whether electricity and natural gas prices depend on the market structure and compare these results to the predictions of a number of theories. The results are most consistent with the political economy theories suggesting that regulators respond to interest group activity.