Abstract: In dealing with street violence, the government holds an information advantage. This paper studies how the government can utilize this advantage to signal public security budgets to induce rioters to surrender, and achieving the goal of stopping violence and restoring order. Street violence incidents are characterized by information asymmetry, antagonistic contradictions, phased developments, and zero-sum games between parties. It is crucial for governments to mobilize resources effectively under full intelligence information to curb violence and restore order. This paper constructs a two-stage signaling game model to analyze the government's optimal strike strategies under different budget scenarios. The model assumes that the government has complete information while rioters have incomplete information, and considers that the government's public security budget is finite. The study shows that when the rioters' expected cost of surrender is less than the loss from government strikes, their optimal strategy is to surrender in the first stage; when the expected losses are low, they tend to resist until the end. If the government has a sufficient budget, it needs to send a signal in the first stage by investing resources greater than the cost of surrender, forcing rioters to surrender in the first stage; otherwise, the government with a smaller budget needs to invest all its resources in the first stage to combat rioters.
This paper uses the 2019 Hong Kong “anti-extradition bill” incident as a case study to validate the model's effectiveness. In the Hong Kong “anti-extradition bill” incident, the rioters updated their beliefs about the government's initial and remaining resources after observing the government's first-stage resource investment, and decided whether to surrender. The results show that when rioters expect the government budget to be sufficient, they will choose to surrender in the first stage; when the expected government budget is insufficient, they will choose to continue resisting. Through the case analysis, the study finds that the government can effectively force rioters to surrender by sending a signal in the first stage with resources greater than the cost of surrender, achieving the goal of stopping violence and restoring order.
The findings of this study provide important insights for governments in handling street violence incidents and managing prolonged conflicts. The paper assumes that the remaining resources will not change in the second stage, i.e., the total resources invested in by the government remain unchanged. In future research, changes in the second stage government resources can be considered for a more in-depth analysis. This paper focuses on the game between the government and rioters under the information advantage, not considering other actors such as social groups, NGOs, and the public, who may potentially become rioters under certain conditions. Future research could incorporate these potential rioters into the model analysis. Additionally, combining smart city big data for precise situational awareness with numerical analysis could lead to more targeted conclusions.
Overall, this paper systematically analyzes how the government can effectively handle street violence incidents by signaling public security budgets under an information advantage, providing theoretical and practical guidance for governments worldwide.

Key words: street violence, signal game, strategy to stop violence and disorder, information advantage, public security budget

摘要： 一些国家和地区爆发的街头暴力事件具有信息不对称、矛盾对抗性、事态发展阶段性和双方零和博弈等特征,各国政府在掌握充分情报信息下如何调动资源实现止暴制乱、恢复秩序是一个重要任务。本文考虑政府具有信息优势背景下,构建两阶段信号博弈模型,分析了政府如何运用公共安全预算的信号促使暴乱分子尽快投降的均衡结果。研究表明:当暴乱分子预期投降成本小于遭受政府打击的损失时,最优策略是在第一阶段选择投降。当暴乱分子预期遭受的打击损失较小时,会采取负隅顽抗到底的策略。当政府用于公共安全预算充裕时,需要在第一阶段发送投入打击资源大于投降成本的最优临界信号,迫使暴乱分子遭受打击后在第一阶段投降。否则,预算较小的政府需要在第一阶段投入所有资源进行打击。

关键词: 街头暴力事件, 信号博弈, 止暴治乱策略, 信息优势, 公共安全预算