Family, Home, and Social Sciences
First Faculty Advisor
C. Arden Pope III
First Faculty Reader
John E. Stovall
sentiment analysis, social media, United States, air pollution, happiness, visibility
This study examines the associations between actual and perceived air pollution (PM2.5, AQI, and ground visibility), weather information, and expressed sentiment via US Twitter. Heterogeneity in the associations across date and county characteristics are also explored.
A sentiment index was constructed using 27,827,828 geotagged U.S. tweets posted between May 31 and November 30, 2015. Associations between AQI category changes and the sentiment index were estimated using multi-cutoff regression discontinuity models. Associations between same-day and lagged PM2.5, ground visibility, and the sentiment index were estimated using weighted linear regression models. Models include weather variables and county and date fixed effects. Stratified analyses by county type (MSA, urban, rural) and date characteristics (holiday or non-holiday, weekday or weekend) were performed.
Being in the AQI category of Moderate rather than Good is estimated to predict a 1.5 percentage point decrease in the sentiment index. A 1-mile increase in ground visibility is estimated to predict roughly a 0.34 percentage point increase in the sentiment index, while increasing PM2.5 is found to predict a very small increase of about 0.02 percentage points per 1 g/m3. Temperature, pressure, wind speed, and precipitation were all found to significantly affect sentiment. Heterogeneous results were observed across both date and county characteristics.
The findings suggest that air pollution has a short-term psychological effect on expressed sentiment via U.S. Twitter but not a physiological effect. Weather variables are also found to be significantly associated with expressed sentiment.
BYU ScholarsArchive Citation
Garcia, George R. III, "Effects of Actual and Perceived Air Pollution on U.S. Twitter Sentiment" (2021). Undergraduate Honors Theses. 184.