The impact of social workers on infant mortality in inter-war Tokyo: Bayesian dynamic panel quantile regression with endogenous variables

Although no comprehensive sickness insurance system existed in Japan until the mid-twentieth century, the infant mortality rate in Japan started to decline from the early twentieth century onwards, specifically owing to health improvements in low-income areas. This paper focuses on the impact of social workers called Homen iin on reducing the infant mortality rate in inter-war Tokyo. These social workers were in charge of the medical casework and provided access to medical treatment for low-income households under the District Committees System. To examine how the activities of these social workers influenced infant mortality, this paper analyses panel data for Tokyo between 1926 and 1937. By employing the dynamic panel quantile regression approach, it is found that the activities of social workers played a vital role in mitigating the risk of infant mortality, especially in areas that had a higher infant mortality rate.