Analytical Screens for Electricity Mergers

Electricity mergers pose distinct challenges for competition policy. Electricity demand is highly inelastic in the short run, storage is limited, and transmission constraints limit the ability to substitute generation at other locations. As a result, a merger can affect prices in many different markets and even generators with small market shares may be able to exercise market power. The U.S. Federal Energy Regulatory Commission’s approach for screening horizontal mergers, based on the concentration thresholds in the Department of Justice/Federal Trade Commission Horizontal Merger Guidelines, can fail to identify mergers that lessen competition, and mergers that fail the FERC screen may have no significant anticompetitive effect. We propose competitive residual demand (CRD) analysis, which examines the supply curves of the markets affected by a merger and considers the ability and incentive of firms to raise prices before and after a proposed merger. CRD analysis is a relatively easy way to address the incentives for generators to exercise market power and relies on data that are often available. Vertical (convergent) mergers between electricity and gas raise additional concerns, and we propose a methodology to screen vertical mergers.