Next month, the Montgomery County Council will vote on a bill to ban single-use plastic bags in the hope of reducing litter and waste by promoting reusable alternatives. While the bill is well-intentioned, evidence suggests that banning plastic bags does more harm than good. Reusable bags pose heightened public health risks, require more natural resources to manufacture, and have not consistently reduced overall bag use. Rather than providing a substantial environmental benefit, such policies risk becoming more symbolic than effective, doing little to preserve our county’s natural beauty.
A 2012 study found that banning plastic bags can lead to a significant increase in food-borne illnesses. After San Francisco’s 2007 plastic bag ban, emergency room visits and deaths from food-borne illnesses rose compared to other California counties without a ban. Similar local increases were noted after subsequent bans across California. This is likely because bacteria from food packaging, especially meat, fish, and produce can linger on reusable bags and contaminate other items during future shopping trips. A 2010 study found bacteria contamination in most reusable bags, with 12% carrying E. coli. Although the proposed ban includes limited exceptions for disposable plastic bags, San Francisco’s similar exceptions did not prevent the rise in food-borne illnesses.
The costs of these food poisoning incidents must be weighed against the benefits of reduced litter and environmental harm. Based on rates seen in San Francisco, a plastic bag ban here could lead to an additional 100 to 300 hospitalizations due to E. coli each year. Although this risk could decrease if people regularly washed their reusable bags, the reality is that few people do. In my experience—and judging by the habits of people I know—the answer is “rarely, if ever.” Some studies have put this number at around 3%.
Even if we all started washing our bags regularly, this would come with its own environmental costs. Washing and drying reusable bags requires 2 gallons of water, soap, and energy per wash, which requires more chemicals and greenhouse gas emissions. Producing a reusable bag also demands far more resources than a single-use plastic bag. That is why, in a competitive market like wholesale packaging supplies, sellers charge 50 times more for cotton bags than plastic ones. This stark price difference in cost reflects the resources used in their production: reusable bags must be used many times—potentially thousands, depending on the material—to offset the environmental impact of their production. A 2011 United Kingdom study found that single-use plastic bags had the lowest environmental impact compared to alternatives like paper or cotton. Moreover, if you reuse a plastic bag even once as a trash bag for other purposes, then any advantage of a reusable bag diminishes further.
Under the new bill, disposable paper bags will still be available but will incur a 10-cent tax. Despite being potentially biodegradable and recyclable, they have a larger environmental footprint compared to plastic bags, are costlier to produce, tear easily, weaken when wet, and are bulkier for reuse—reasons stores originally switched to plastic.
Additionally, evidence suggests that bag bans may not lead to lasting changes in behavior. After the initial enthusiasm for reusable bags wanes, people often revert to their old habits—buying whatever bags are available, sometimes accumulating a pile of ‘reusable’ bags that are used only a few times. Reporting by the Los Angeles Times in 2023 highlighted this issue: following a disposable plastic bag ban, many people began buying an endless stream of reusable bags, which are far more resource-intensive to produce than disposable ones.
Littering in public spaces exemplifies what economists call a negative externality—when the person responsible for an action does not bear its full costs, leaving others to deal with the consequences. Negative externalities are often cited as a justification for government intervention, an idea that traces back to the economist Arthur Pigou in the early 20th century. Since the 1950s, the environmental movement has adopted Pigou’s arguments to support taxes that discourage pollution. Indeed, the current Montgomery County carryout bag law is a Pigovian tax: it discourages litter by taxing bags and directs the revenue to the county’s clean water initiatives.
These taxes have their place, but it’s important to recognize that there are no perfect solutions—only trade-offs. Given the health implications and potential negative environmental impacts associated with a complete transition to reusable bags, if plastic bag litter is a significant concern in Montgomery County, raising the current bag tax may be more effective than an outright ban. A tax offers several advantages over a ban: it allows people to continue using disposable bags for raw meats and other frequently contaminated foods, and the incremental revenue could be used to fund important local environmental projects.
When making policy decisions, we must carefully weigh the expected benefits and costs. With a majority of the council members sponsoring the bill, it is poised to pass, but the costs will likely exceed the benefits. Instead, the council should look for alternatives that will do more to keep our streets clean while keeping our residents healthy and reducing our environmental impact.
Benjamin Kay is an economist that specializes in cost benefit analysis and Margery Smelkinson is an infectious disease scientist. Both are Montgomery County residents.
