Plastic bag bans cut pollution and protect wildlife, US studies find

Policies restricting plastic packaging are effective in reducing waste and benefiting ecosystems while influencing consumer behavior, according to two recent studies conducted in the US. The findings provide real-world evidence supporting local and national policy action.

Researchers at the University of Delaware and Columbia University, published in Science, analyzes data from over 45,000 shoreline cleanups across the US, alongside the implementation of hundreds of plastic packaging policies that were adopted in the country between 2017 and 2023.

The research shows that these policies lead to a decrease in plastic bag litter by 25% to 47%, as a proportion of total waste collected relative to areas without policies. 

Anna Papp, an environmental economist and the study’s lead author, tells Packaging Insights: “The decrease growing in magnitude over time could be due to things like increased customer awareness and increased enforcement and compliance from stores.”

She says her team differentiated between different types of policies and found that complete bans and bag fees are “more robust than partial bans, likely due to the less complete coverage of partial bans, which only ban thin plastic bags.”

“It seems that many policymakers are already aware of this, as partial bans have been less popular in recent years, but continued attention to which policies are effective and could be important to continue the momentum.”

Protecting ecosystem

The study also explored potential ecological benefits, as regions with plastic bag policies reported 30% to 37% fewer incidents of animals entangled in plastic waste.

Researchers suggest expanding single-use bag bans or fees would continue to cut plastic pollution in the environment.“Reading through the policies highlighted that many jurisdictions are motivated by the negative effects of plastic bags on animals and ecosystems. This is one reason we included an analysis on animal entanglements, though future research is needed there as our results are only suggestive,” shares Papp.

“In terms of future hopes, our findings offer large-scale and robust evidence that these types of policies do work in limiting plastic bag litter in the environment, especially in areas with high concentrations of plastic bag litter.” 

“However, these policies only reduce plastic bag litter, not other types of plastic. While harmful and common, plastic bags are still just one of many types of plastic waste in the environment, and these policies address only a small part of the long lifecycle of plastics,” she adds.

Strong public support

A separate study from the University of Vermont examined the state’s single-use plastic bag ban that was passed in 2019 and took effect in July 2020.

Published in Environmental Economics and Policy Studies, the research shows that self-reported plastic bag use in Vermont dropped by over 91%, while paper bag use rose by over 6% after the state-level legislation in Vermont that banned single-use plastic bags and imposed a fee on paper bags.

Respondents expressed satisfaction with the law’s rollout and enforcement, though there was limited support for extending regulations to paper bags. Researchers suggest that it could be due to the communication work that the state of Vermont did before implementation day.Studies find policy interventions and consumer behavior are linked, with each influencing the other

Meredith Niles, a co-author of the study, says: “The biggest finding here is that this legislation clearly had an impact on consumer plastic bag use and, equally importantly, that there was broad and wide public support for the plastic bag ban. I think it demonstrates a great policy outcome, and that doesn’t always happen.”

Developing regions are stepping up local efforts to ban single-use plastics. Islamabad, Pakistan launched multiple “crackdowns” on single-use plastic as part of a broader waste removal campaign, while Malaysia’s Penang state introduced an initiative to eliminate single-use plastic bags before a statewide ban set to take effect this September.

Papp says bag policies are nowhere close to a “solution” on plastics and addressing the production or supply of plastics. She suggests that the UN Global Plastic Treaty “is likely to be crucial” in the fight against pollution.