Ex-post vs. ex-ante regulation on platforms' discriminatory pricing under different market structures: an evolutionary game study

Digital platforms are becoming increasingly ubiquitous in everyday life; however, they present serious and complex monopoly problems, one of which in particular has not been resolved: the problem of discriminatory pricing. The regulatory measures in China are almost invalid because they do not target different market structures; moreover, traditional ex post regulation is insufficient. Therefore, we propose an ex-ante regulatory mechanism based on the prior commitment approach and establish evolutionary game models under different market structures to analyze the effectiveness of regulatory strategies. The theoretical research and simulation results show that the ideal state can be achieved when the ex-ante regulation strategy is adopted under different market structures; moreover, we find that the government's regulatory strategy should be targeted according to the stage of the platform, adopting loose ex post regulation in the initial development stage, while adopting the ex-ante regulation strategy when the platform has monopoly power. We also numerical simulations to verify the stability of our conclusions and analyze the impact of key parameters on the game structure. Potential policy implications are also proposed.