When Externalities Collide: Influenza and Pollution
Influenza and air pollution are significant public health risks with large economic consequences shared across the globe. The common etiological pathways through which they harm health present an interesting case of compounding risk via interacting externalities. Using regional and temporal variation in pollution and disease transmission, we find exposure to more air pollution significantly increases influenza hospitalizations. By exploiting the random deviations in influenza vaccine effectiveness over time, we show high influenza vaccine effectiveness neutralizes this relationship. This suggests seemingly disparate policy actions of pollution control and expanded vaccination provide greater returns than found when studied in isolation.
We thank Max Auffhammer, Luisa Osang, Jeffrey Shaman, and participants at the University of California Environmental Economics seminar for helpful discussions. All errors are our own. The IRB for access to the HCUP data through the National Bureau of Economic Research (NBER) was approved by the NBER. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.
Matthew J. Neidell