The paradox of plastic bag legislation: How bans and taxes affect PM2.5 air pollution in 208 countries.

Widespread use of plastic bags contributes to elevated air pollution levels worldwide, prompting various regulatory measures such as bans and taxes aimed at reducing plastic pollution. The objective of this study was to analyze the impact of these plastic bag bans and taxes on PM2.5 air quality across 208 countries from 1960 to 2021, using Fixed Effects, Driscoll and Kraay, and GMM models. Results indicate that bans generally reduce the population's exposure to PM2.5 above WHO guidelines, but increase exposure above the Interim Target-1, while reducing it above Interim Target-3 in some models. Conversely, taxes on plastic bags significantly increase both mean annual PM2.5 exposure and the proportion of the population exposed to levels surpassing all WHO targets. The combined effect shows a decrease in exposure due to bans, except for an increase above Interim Target-3, while taxes increase exposure across all measures. These findings highlight complex interactions between plastic bag policies and air pollution, emphasizing the need for careful policy design. While plastic bag bans effectively reduce PM2.5 exposure, taxes on plastic bags unexpectedly increase it, emphasizing the need for carefully designed policies to prevent unintended increases in air pollution.