Replication Data for: How Uncertainty about War Outcomes Affects War Onset

In canonical accounts of war, conflict outcomes are inherently uncertain. Contesting literatures posit that this uncertainty, arising from stochastic elements of the war-fighting process, may induce conflict due to greater risks of miscalculation or foster peace by breeding caution. We theorize that states, on average, exhibit prudence when confronting greater uncertainty. Despite its conceptual importance, extant proxies for uncertainty at various levels of analysis—such as polarity, balance of power, system concentration, and dyadic relative capabilities—are imprecise and theoretically inappropriate indicators. To overcome this shortcoming, we theorize the conditions that elevate the magnitude of uncertainty over conflict outcomes and introduce a novel measure that captures this uncertainty within any k-state system. Through extensive empirical analysis, we confirm uncertainty’s pacifying effect and show how this effect operates at different levels of analysis.在经典战争研究的标准叙事中，冲突结局本质上具有不确定性。相互对立的研究文献提出，这种源于作战进程随机因素的不确定性，既可能因误判风险加剧而引发冲突，也可能通过催生审慎态度以促成和平。我们提出理论假说：平均而言，国家在面对更高程度的不确定性时会展现出审慎姿态。尽管不确定性在概念层面具有重要价值，但现有不同分析层级下的不确定性替代指标——如体系极数、权力均势、体系集中度以及双边相对战力——均不够精确，且在理论上并非恰当的衡量指标。为克服这一缺陷，我们从理论上界定了推高冲突结局不确定性程度的相关条件，随后提出了一种可在任意k国体系（k-state system）中捕捉此类不确定性的全新衡量方法。通过大规模实证分析，我们验证了不确定性的和平效应，并阐明了该效应在不同分析层级中的作用机制。