Working Paper: NBER ID: w15056
Authors: Katherine Ho; Matthew Neidell
Abstract: In this paper we consider how the dental industry responded to the addition of fluoride to public drinking water. We take advantage of the staggered introduction of fluoridation throughout the country to analyze the changes in numbers of within-county dentists relative to physicians in the years surrounding the change in fluoridation status. We find a significant decrease in the number of dental establishments and an even larger reduction in the number of employees per firm following fluoridation. We also find that fluoridation in neighboring markets was associated with an increase in own-market dental supply, suggesting that dentists responded to the demand shock by moving from fluoridated areas to close-by markets. Further analysis suggests that some dentists may have retrained as specialists rather than moving geographically. Our estimates imply that the 8 percentage point change in exposure to water fluoridation from 1974 to 1992 may have led to the loss of as many as 0.6 percent of dental establishments and 2.1 percent of dental employees, suggesting a substantial net impact of this public good on the dental profession since its inception.
Keywords: community water fluoridation; dentists; public goods
JEL Codes: H41; H51; I11; J24; L22
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| community water fluoridation (CWF) (Q25) | number of dental establishments (L84) |
| community water fluoridation (CWF) (Q25) | number of employees per establishment (L25) |
| CWF in neighboring counties (R23) | dental supply in own county (I11) |
| community water fluoridation (CWF) (Q25) | composition of dentists (J44) |
| community water fluoridation (CWF) (Q25) | net loss of dental establishments and employees (L84) |