Research on the Competitiveness and Market Power Assessment of High Concentration Electricity Spot Market Based on Structure-Conduct-Performance Theory

China's electricity spot market on the generation side is characterized by high market concentration, making the assessment of market competitiveness and market power particularly important. By reviewing domestic and international literature on market power, this paper proposes a method for assessing market competitiveness and market power that is suitable for high-concentration electricity markets. Ex-ante structural tests are used to evaluate whether market entities have the objective conditions to exercise market power; ex-interim behavioral tests are used to assess whether market entities have a strong incentive to exercise market power; and ex-post performance tests are used to evaluate whether market entities have obtained excess profits and influenced market prices through the exercise of market power. Finally, through case analysis, the paper demonstrates the rationality and feasibility of the proposed methods for assessing competitiveness and market power