Abstract: A large number of spam reviews have been encouraged by the cashback incentives for favorable comment on C2C platform, and the phenomenon has damaged the platform's credit evaluation mechanism. The dynamic evolution of the cash back for favorable comment not only stems from the interaction between the buyer and the seller on C2C platform, but also depends on their behavioral psychology. Therefore, the psychology theory is worth being introduced to explore the evolutionary mechanism of the cash back for favorable comment on C2C platform. In this paper, the prospect theory and risk perception factors are integrated into the evolutionary game analysis to build the perceived benefit matrix, which is different from the traditional benefit matrix. In this case, the dynamic evolutionary process of buyers' and sellers' behaviors can be better depicted under the setting of reward and punishment mechanism. From the perspectives of prospect theory and risk perception, the reasons why the stability conditions of optimal evolution results are difficult are illustrated to meet and the effects of evolutionary results caused by different parameters are simulated; therefore, the measures to manage the cash back for favorable comment are proposed. The result indicates:(1)Decision-maker's cognitive and optimistic bias and deterministic and reflective effect make it difficult for the system to converge to the optimal evolutionary stable point; (2)Improving decision-maker's perception of "gain" and "loss" and the loss aversion contributes to an evolutionary optimal result; (3)The evolutionary tendency and stability of the strategy can be changed when the following factors fluctuate around their critical point:the initial selection probability of both sides in the game, the earning of negative review, moral cost and public interest perception of buyers, the sellers' OPEX of cash back for favorable comment or not and the gain of contending for markets.In view of the cash back incentives for favorable comment, a theoretical analysis and quantitative research on the strategic interaction between the buyer and the seller on the C2C platform are conducted. This paper aims to provide theoretical support for relevant departments to manage credit speculation.

Key words: prospect theory, online review, cash back for favorable comment, value perception, evolutionary game