Should cities eliminate plastic bag bans? It is complicated

Single-use plastic bags are a scourge for the environment. Americans alone use 100 billion of them every year, according to the Center for Biological Diversity (CBD), which says it takes 1,000 years for plastic bags to degrade in a landfill. And even then, plastic bags don’t break down completely. Instead, they photodegrade, becoming microplastics that absorb toxins and continue to pollute the environment. Meanwhile, birds, sea turtles and fish regularly mistake discarded plastic bags for food, which can cause illness and death up the food chain.

For these reasons and more, environmentally conscious communities around the world have banned restaurants and retailers from using single-use plastic bags. Instead, businesses and consumers are being encouraged to use recyclable paper bags or reusable cloth bags, based on the logic that they’re better for the Earth.

California became the first US state to ban plastic bags in 2014. Since then, six more states have followed suit with statewide bans, and more than 500 municipalities in 28 states with local bans, reports, a website dedicated to information about laws that limit the use of plastic bags.

There is no doubt that the architects of the plastic bag ban feel they are doing the environment good. New research from the University of Georgia (UGA), however, suggests that their efforts may actually be doing more harm than good.

The reason is simple: single-use plastic bags are not really single-use. Although consumers don’t typically reuse them when shopping, they do reuse them in other ways, such as basket liners. In communities where they do not receive plastic bags in stores, consumers are therefore looking for alternatives. Often this means buying small plastic garbage bags, which increases rather than decreases the population of plastic bags in landfills and in the environment.

“We know there is a demand for the use of plastic bags, and we know that if these policies come into effect, some bags will disappear or become more expensive to obtain,” said Yu-Kai Huang, postdoctoral researcher at the UGA Warnell School of Forestry and Natural Resources, said in a Press release. “So we wanted to see the effectiveness of this policy in reducing overall bag usage.”

While previous studies have looked at the effect of plastic bag bans on plastic bag consumption, Huang and his colleague, Richard Woodward of Texas A&M University, wanted to dig deeper. So, they measured plastic trash bag sales in counties that have plastic bag bans or taxes, and then compared them to plastic trash bag sales in counties that don’t. Their findings are striking: In California, sales of 4-gallon trash bags increased 55% to 75% in communities with bag policies, while sales of 8-gallon trash bags increased 87% in 110%. Meanwhile, sales of 13-gallon trash bags — the size typically used in kitchen trash cans — remained relatively flat.

The increase in sales is measurable not only in dollars but also in pounds. For example, additional sales of 4-gallon trash bags increased plastic consumption by 30 to 135 pounds per store per month, Huang and Woodward found. Additional sales of 8-gallon trash bags also increased plastic consumption from 37 pounds to 224 pounds per store per month.

“To-go grocery bags were replaced with similarly sized trash bags before the regulations were implemented,” Huang wrote in the study. “After the regulations came into force, consumer demand for plastic bags shifted from regulated plastic bags to unregulated bags.”

A 2017 study by Recyc-Québec, a Montreal-based environmental organization, also suggests that banning plastic bags could be problematic. Not only because they can be reused as wastebasket liners, but also because they require less energy and materials to produce.

And yet, communities shouldn’t necessarily be rushing to repeal their plastic bag bans. Because in high-volume stores, bans could still have a positive impact. For stores that generate at least 326 take-out plastic bags per day, for example, or nearly 10,000 per month, banning plastic bags results in fewer plastic bags being sent to landfills.

There is no denying that reducing plastic demand and production is the way forward to reduce the wider problem of plastic pollution and banning bags can be part of the wider solution. Yet this study highlights how well-meaning policies can have unintended downsides.

Huang concluded, “There is no clear answer to this. The reuse of free grocery bags provided is key to determining the overall effectiveness of grocery bag policies.

Huang and Woodward’s analysis – which includes variables such as income and population density, both of which can affect the amount of waste generated by communities – appears in the journal Environmental and Resource Economics.

Bryce K. Locke