Abstract: To understand the decision-making mechanism of social media users' spontaneous dissemination of crisis information, this paper discusses the boundary conditions and decision-making paths that trigger public crisis communication behavior based on HSM dual-system cognitive processing theory. Taking the moral appeal and utilitarian appeal often involved in crisis information into consideration, this paper examines the main effects of the two distinct kinds of crisis message appealing contents using econometric models. Moreover, this work focuses on two types of negative discrete emotions (i.e., anger and anxiety) with significant differences in certainty, and investigates the multiple complex moderating effects of them. Finally, the empirical research is completed through the multi large-scale datasets collected by Sina Microblog and Twitter platform during public crisis events. The results show that, (1) both moral appeal and utilitarian appeal will promote public crisis communication behavior; (2) anger-embedded strengthens the influence of moral appeal whereas it weakens the influence of utilitarian appeal on public crisis communication; (3) on the contrary, anxiety-embedded promotes the utility of utilitarian appeal on the public’s decisions but hurt the effect of moral appeal on them. The conclusion provides important decision support and theoretical basis for China’s public crisis management.

Key words: Public crisis emergencies, Crisis information dissemination, Message appeal, Negative discrete emotions, Cognitive decision