The Effects of Fluoride in Drinking Water
利用瑞典登记数据，研究饮用水中天然氟化物对牙齿健康、认知能力和劳动收入的影响，发现氟化物改善牙齿健康、提高低收入人群的劳动收入，但对认知能力无显著影响。
Water fluoridation is a common but debated public policy. In this paper, we use Swedish registry data to study the causal effects of fluoride in drinking water. We exploit exogenous variation in natural fluoride stemming from variation in geological characteristics at water sources to identify its effects. First, we reconfirm the long-established positive effect of fluoride on dental health. Second, we estimate a zero effect on cognitive ability in contrast to several recent debated epidemiological studies. Third, fluoride is furthermore found to increase labor income. This effect is foremost driven by individuals from a lower socioeconomic background.