Working Paper: NBER ID: w27604
Authors: Hunghao Chang; Chad Meyerhoefer; Fengan Yang
Abstract: Recent studies demonstrate that air quality improved during the coronavirus pandemic due to the imposition of social lockdowns. We investigate the impact of COVID-19 on air pollution in the two largest cities in Taiwan, which were not subject to economic or mobility restrictions. Using a generalized difference-in-differences approach and real-time data on air quality and transportation, we estimate that levels of sulfur dioxide, nitrogen dioxide and particulate matter increased 5 - 12 percent relative to 2017 - 2019. We demonstrate that this counterintuitive finding is likely due to a shift in preferences for mode of transport away from public transportation and towards personal automobiles. Similar COVID-19 prevention behaviors in regions or countries emerging from lockdowns could likewise result in an increase in air pollution.
Keywords: COVID-19; Air Pollution; Transportation Preferences; Taiwan
JEL Codes: I12; Q53
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| COVID-19 pandemic (H12) | increase in levels of sulfur dioxide (SO2) (Q53) |
| COVID-19 pandemic (H12) | increase in levels of nitrogen dioxide (NO2) (Q53) |
| COVID-19 pandemic (H12) | increase in levels of particulate matter (PM10) (Q53) |
| COVID-19 pandemic (H12) | increase in levels of particulate matter (PM25) (Q53) |
| shift in transportation preferences from public transportation to personal automobiles (R41) | increase in levels of sulfur dioxide (SO2) (Q53) |
| shift in transportation preferences from public transportation to personal automobiles (R41) | increase in levels of nitrogen dioxide (NO2) (Q53) |
| shift in transportation preferences from public transportation to personal automobiles (R41) | increase in levels of particulate matter (PM10) (Q53) |
| shift in transportation preferences from public transportation to personal automobiles (R41) | increase in levels of particulate matter (PM25) (Q53) |
| increase in confirmed COVID-19 cases (I15) | increase in levels of sulfur dioxide (SO2) (Q53) |
| increase in confirmed COVID-19 cases (I15) | increase in levels of nitrogen dioxide (NO2) (Q53) |
| increase in confirmed COVID-19 cases (I15) | increase in levels of particulate matter (PM10) (Q53) |