When food waste ends up in landfills, it produces lots of planet-warming methane emissions. To curb this, states across the country have been enacting bans to keep food waste out of the trash. But most of those laws haven’t been effective—except for the ban in Massachusetts.
That’s according to a study out today in the journal Science, in which researchers looked at the first five U.S. states to implement bans on commercial food waste: California, Connecticut, Rhode Island, Vermont, and Massachusetts. In four states, the bans (which all focused on commercial food waste) essentially did nothing to reduce the waste that ended up in landfills.
But Massachusetts achieved a 13.2% reduction in waste, and a 25.7% decrease in methane emissions per ton of waste. The researchers found three clear reasons why that ban was effective, which could be a model for other states.
How researchers assessed food waste bans
Researchers looked only at attempts to rein in commercial food waste, like from restaurants, food manufacturers, grocery stores, and so on. (Some states have also implemented bans on residential organic waste, including food scraps and lawn trimmings; but that sort of data has become sparser after the pandemic, researchers say.)
To figure out whether or not the states’ food waste bans were effective, the researchers first had to determine the expected effects of the laws. Basically, “If things were working perfectly, then what is the total amount of waste they were supposed to divert from landfills?” says Fiori Anglou, a coauthor of the paper who conducted the research as a PhD candidate at the University of Texas at Austin’s McCombs School of Business.
To do that, the researchers used data from state agencies to understand each region’s waste stream; in Massachusetts, for example, they discovered that commercial food waste generators produced about 10% of all waste in the state. Then, they looked at each state ban to see what exactly was covered by the law—some states’ bans also covered buildings like schools, and some laws differed based on the amount of waste produced. In some cases, local policymakers made statements about how much the bans could reduce food waste. Most states expected their bans to lead to 10% to 15% less waste in landfills.
Once they figured out how the laws were meant to work, they compared each state to similar ones without a ban, to see what would have happened if the law weren’t implemented. (California, for example, was compared to the average of Georgia, North Carolina, and South Carolina; combined, those “control” states had an average amount of annual waste that matched California’s.) “In every other state except for Massachusetts, we basically can’t find any effect whatsoever,” says Ioannis Stamatopoulos, another coauthor and associate professor at UT Austin’s McCombs School of Business. “And remarkably, Massachusetts achieved precisely the expected effect.”
3 reasons why Massachusetts’s food waste ban worked
Massachusetts stood out as having an effective food waste ban because it had three clear features: a simple law with a small number of exemptions; a robust network of composting infrastructure so it was easy and affordable for businesses to compost rather than trash their food waste; and an enforcement system. “In all those dimensions, Massachusetts was a clear outlier,” Stamatopoulos says.
The researchers didn’t tease out which of those three factors was most effective. Instead, they say it was the combination. But the other states clearly lacked some of those elements. Massachusetts, the researchers found, had more than triple the number of inspections per business that generated food waste than the next closest state, which was Vermont. The other three states had almost no enforcement, including inspections or fines.
Massachusetts also had the most facilities to process food waste, at a density 51% higher than the second-densest state (Vermont). And the law there was simple: it applied to all commercial businesses that generate more than half a ton of food waste per week.
Food waste is an important issue for states to solve. When food ends up in landfill, it produces more methane emissions than any other type of trash; an estimated 8% to 10% of total global greenhouse gas emissions come from food waste. But states can’t just pass food waste bans and hope they work, Stamatopoulos says. “[You have to] make sure the law is such that the relevant businesses can comply at a reasonable cost; and if they don’t, someone has to be there to check.”
If people aren’t complying with a law, it’s because they’re simply responding to the incentives, says Robert Evan Sanders, another coauthor and a professor at the University of California, San Diego, Rady School of Management. “If it’s too costly to comply, if no one’s enforcing it, people are not following the law,” he says. “You can think of our results as kind of shedding light on really widespread noncompliance with some of these laws.”
Other states could follow Massachusetts’s lead and get food waste producers to comply with bans, he adds—if they’re willing to invest the resources to build up their composting network and enforcement protocols. “You hear a lot of ‘more versus less’ regulation, and that’s not what it comes down to,” he says. “It comes down to better-supported versus not-supported regulation.”