How does the information richness of public opinion response affect response effect in sudden public crisis events?

In sudden public crises, the proliferation of online rumors exacerbates public panic and social risks, posing a severe challenge to the government's ability to respond to public opinion. How to improve the effectiveness of public opinion response, as well as the impact mechanism of individual level public opinion response, is an important issue in the field of emergency management. The information richness of public opinion response is a key element. However, existing research has focused more on the timeliness and authority of responses, and there is insufficient exploration of the mechanisms by which the key dimension of "information richness" affects public psychology and behavior. This article combines the characteristics of public opinion response and risk perception and constructs a dual path model by integrating cognitive behavior theory and dual system theory. Three sets of pre- and post-test investigation experiments (N=370) were used for testing. The findings reveal that (1) A response with high information richness can not only directly improve public satisfaction and suppress the spread of rumors, but also indirectly reduce risk perception by reducing negative emotions (emotional pathway) and utilizing government trust (cognitive pathway). (2) Government trust positively moderates the relationship between information richness and risk perception, with higher trust resulting in stronger response effects. This study reveals the deep psychological mechanism of information richness in crisis communication, providing precise theoretical basis for the government to optimize public opinion response strategies.