Applied Micro Lunch Seminar: Shuhei Kaneko, University of California, Santa Barbara

Speaker

Shuhei Kaneko, University of California, Santa Barbara

Title

"Fluoride at Low Doses: Dental Health and Adolescent Self-Esteem"

Abstract

While the effects of fluoride in drinking water on dental health and human capital remain central to public health debates, most existing evidence focuses on dosages from community fluoridation. We estimate the causal impacts of childhood exposure to lower fluoride levels, exploiting quasi-exogenous variation in naturally occurring concentrations shaped by regional geology in Japan. Combining this variation with longitudinal survey data, nationally representative medical claims, and patient surveys, we provide comprehensive evidence on fluoride's effects. Even at low concentrations, fluoride substantially improves dental health in childhood and adolescence.

Importantly, fluoride exposure also enhances self-esteem among adolescent girls, operating through improved appearance: fewer cavities reduce the likelihood of visible dental problems, and these improvements in dental aesthetics foster their confidence. We find no adverse effects on cognitive performance or educational attainment, in contrast to concerns raised by studies of higher exposures. Taken together, our results show that fluoride remains effective even within a well-developed health system such as Japan's and indicate a conservative lower bound for concentrations that yield dental and psychosocial benefits without cognitive risks.