Restructuring electricity markets has enabled wholesalers to exercise market power. Using a common method to measure competition, several studies have found substantial inefficiencies. This method overstates actual welfare loss by ignoring production constraints that result in non-convex costs. I develop an alternative method that accounts for these constraints and apply it to the Pennsylvania, New Jersey, and Maryland market. For the summer following restructuring, the common method implies that market imperfections resulted in considerable welfare loss, with actual production costs exceeding the competitive model's estimates by 13%–21%. In contrast, my method finds that actual costs were only between 3% and 8% above the competitive levels.

Real-time pricing (RTP) of electricity would improve allocative efficiency and limit wholesalers' market power. Conventional wisdom claims that RTP provides additional environmental benefits. This paper argues that RTP will reduce the variance, both within- and across-days, in the quantity of electricity demanded. We estimate the short-run impacts of this reduction on SO2, NOx, and CO2 emissions. Reducing variance decreases emissions in regions where peak demand is met more by oil-fired capacity than by hydropower, such as the Mid-Atlantic. However, reducing variance increases emissions in more U.S. regions, namely those with more hydropower like the West. The effects are relatively small.

This paper examines vertical arrangements in electricity markets. Vertically integrated wholesalers, or those with long-term contracts, have less incentive to raise wholesale prices when retail prices are determined beforehand. For three restructured markets, we simulate prices that define bounds on static oligopoly equilibria. Our findings suggest that vertical arrangements dramatically affect estimated market outcomes. Had regulators impeded vertical arrangements (as in California), our simulations imply vastly higher prices than observed and production inefficiencies costing over 45 percent of those production costs with vertical arrangements. We conclude that horizontal market structure accurately predicts market performance only when accounting for vertical structure.