Abstract: The platform’s performance of corporate social responsibility (CSR) is an important factor affecting the choice of users. Based on two-sided market theory and game analysis methods, the price decisions of two competition platforms are modeled in three cases where CSR is performed by neither, both or only one of the platforms, with the preference of bilateral users for platform responsibility obeying continuous distribution. The model solution and numerical simulation are carried out to analyze the influence of the CSR behavior of the platform on the competition equilibrium and social welfare. The results show that under the competition of two platforms, the CSR level, price level, user scale and profit of the CSR-performing platform will decrease monotonically with its CSR cost coefficient; the price level, user scale and profit of the CSR-nonperforming platform will change inversely. Under the competition of two platforms, the CSR-performing platform holds the upper hand, but the profit of both CSR-performing platforms is lower than that of both CSR-nonperforming platforms, hence the phenomenon of prisoner’s dilemma. Nevertheless, the consumer surplus and social welfare will increase when both platforms perform CSR.

Key words: two-sided platform, platform competition, corporate social responsibility, price decision, user random preference