This study explores the validity of chain effects of clean water, which are known as the "Mills-Reincke phenomenon," in early 20-century Japan. Recent studies have reported that water purifications systems are responsible for huge contributions to human capital. Although some studies have investigated the instantaneous effects of water-supply systems in pre-war Japan, little is known about the chain effects of these systems. By analyzing city-level cause-specific mortality data from 1922 to 1940, we find that a decline in typhoid deaths by one per 1000 people decreased the risk of death due to non-waterborne diseases such as tuberculosis and pneumonia by 0.742-2.942 per 1000 people. Our finding suggests that the observed Mills-Reincke phenomenon could have resulted in the relatively rapid decline in the mortality rate in early 20-century Japan.

中文翻译：

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清洁水的连锁效应：20世纪初日本的Mills-Reincke现象。

这项研究探讨了在20世纪初期的日本，纯净水的连锁效应的有效性，这种连锁效应被称为“米尔斯-雷因克现象”。最近的研究报告说，水净化系统为人力资本做出了巨大贡献。尽管一些研究调查了战前日本供水系统的即时影响，但对这些系统的连锁影响知之甚少。通过分析1922年至1940年的城市特定病因死亡率数据，我们发现伤寒死亡人数每千人下降1个，从而使非水传播性疾病（如肺结核和肺炎）的死亡风险降低了每千人0.742-2.942人。