Understanding the benefits and mechanisms of working from home as a sustainable urban strategy on air pollution: Empirical study in 19 cities in China

Working from home (WFH) arrangements are already acknowledged as a sustainable measure for alleviating urban congestion and air quality issues, but fewer large-scale empirical studies investigating the benefits and mechanisms of WFH on air pollution (AP). The exogenous shock of the epidemic provides unique conditions that enable us to conduct empirical studies on the positive impacts of working from home. Building upon this background, this paper designs a series of empirical models to investigate the benefits of WFH on AP and the mediating effect of intra-city travel intensity (ITI) concerning the WFH-AP relationship to depict the mechanism of the impact of WFH on AP. This paper collected panel data on ITI and AP from January 1 to March 15, 2020, in 19 cities in China for regression analyses. The findings indicate that WFH reduces ITI by 65.0%, while an increase in ITI leads to higher AP emissions, particularly of NO2. WFH positively impacts urban air quality, resulting in a 26.3% decrease in the Air Quality Index (AQI) and reductions of 17.2%, 4.1%, 32.7%, 18.8%, and 13.6% for the five air pollution categories (CO, NO2, PM2.5, PM10, SO2) respectively. Intermediate analyses demonstrated that ITI partially mediated the decrease in AQI, PM2.5, and CO, while PM10 and NO2 showed complete mediation. However, ITI had a weak mediating effect on SO2 emissions. The contribution of this study is that it provides supporting evidence that working from home positively impacts urban air quality and commuting. Additionally, it offers urban administrators a fact-based approach to traffic management and environmental protection, pointing to important directions for future urban sustainability strategy development.