VERMONT banned slavery before the rest of America, back in 1777, and local greens talk like they have just achieved something comparable. “We’re first again,” exults Will Allen, a delighted organic farmer, as the Green Mountain state prepares to require labelling of foods containing genetically modified (GM) ingredients. As The Economist went to press Peter Shumlin, Vermont’s governor, was set to sign a bill that would come into force in July 2016.

Vermont is a quirky mix: it has strict environmental rules, loose gun laws and America’s only self-proclaimed socialist senator. It also takes its food very seriously, says Andrea Stander of Rural Vermont, a group that advocates a “local food system which is self-reliant and based on reverence for the earth”. Per capita, Vermont has more organic farms than any other state. Montpelier is America’s only McDonald’s-free state capital.

A fitting place, then, for a law designed to satisfy the unfounded fears of foodies. Repeated studies have found no threat to human health from GM ingredients, which are found in up to four-fifths of processed food in American shops; nor have any ill effects appeared during the 20 years in which Americans have been eating the stuff. Indeed, ever since the genetically engineered Flavr Savr tomato reached supermarket shelves in 1994 Americans have taken a more relaxed approach to the technology than much of the rest of the world. Some 64 countries, including the 28 of the European Union, require labelling. America does not, but that is changing.

In 2012 and 2013 GM-labelling initiatives in, respectively, California and Washington state failed narrowly after biotech and food companies spent millions on ads to persuade voters that they would be costly and pointless. Last year Maine and Connecticut passed labelling laws, though both have trigger provisions stopping them from taking effect until nearby states follow suit. Generic polling finds 90% or more of Americans in favour of compulsory labelling. Over a million have signed petitions urging the federal Food and Drug Administration (FDA), which oversees national food-labelling rules, to mandate labelling of GM food. (In 1992 the FDA ruled that since there was no material difference between GM and non-GM food, labelling was not required.)

Rural Vermont’s website has a cartoon depicting GM foods as radioactive mutant creatures with eyes on stalks. But most campaigners downplay the wildest claims about Frankenfoods, preferring to emphasise consumer choice, which is hard for GM food producers to argue against.

If they lobby to suppress information, consumers may wrongly assume they have something to hide. Yet if the government requires labels, consumers may assume that this is an official health warning, even if it isn’t. Europeans shunned GM food after labels were introduced, and many European supermarkets declare themselves (not entirely accurately) GM-free. The same could happen in America. “The activists did a great job of scaring people about their food sources,” sighs Norm McAllister, a farmer (and Republican state senator) who grows GM corn in Vermont.

The fatuous fear of Frankenfoods

Genetic modification is one of the most promising tools for feeding a global population that will one day hit 9 or 10 billion. Yet its development depends partly on consumers in rich countries, since the 842m malnourished people don’t have much spare cash. As with other technologies, the techniques honed in rich countries tend eventually to spread to poor ones. But if greens scare Americans into rejecting GM food entirely, that benign process may be interrupted.

Vermont (population 626,000) is small enough that food firms could withdraw their products from its shelves at no great cost. But dozens of states, including California, are considering labelling bills. If they pass, America would have a patchwork of labelling laws, creating a financial and logistical headache. Food firms would have to separate GM from non-GM ingredients, disrupting the whole supply chain. Prices would rise for everyone.

Aware of the threat, the food industry is seeking federal help. The Grocery Manufacturers Association, an industry body, has convened 35 food organisations to lobby for a law that would oblige the FDA to test all new GM traits before they reach the shelves, and to finalise guidelines for a voluntary labelling regime. Crucially, this would preclude state laws that mandate labelling, like Vermont’s. The organic lobby, naturally, cries foul. But, points out Greg Jaffe of the Centre for Science in the Public Interest, an advocacy group, in other countries compulsory labelling has tended to restrict consumers’ choice; try finding GM products in European supermarkets. As things stand, those who want to avoid GM foods can buy organic products. Moreover, state laws are often badly written; the California and Washington initiatives contained impossible-to-attain “zero-tolerance” provisions that could have led to endless lawsuits. Retailers and some manufacturers are already shifting with the wind. Whole Foods, a supermarket for the rich, plans to introduce GM labelling for all products by 2018. Ben & Jerry’s, a Vermont-based maker of pricey ice-cream, plans to source all its products with non-GM ingredients by the end of the year, as it already does in Europe. Even Walmart, America’s largest food retailer, is reported to have softened its stance on labelling. A legal challenge to Vermont’s law looks likely, possibly on free speech grounds. The bill provides for a defence fund, partly filled by taxpayers. “A $1m lawsuit is nothing to California,” says David Zuckerman, a state senator and organic farmer who supported the bill, “but for little Vermont that would be significant.”

The outlook is unappetising. Food scares are easy to start but hard to stop. GM opponents, like climate-change deniers, are deaf to evidence. And the world’s hungry people can’t vote in Vermont.