STAFF at the Madonna Rehabilitation Hospital in Lincoln, Nebraska can sometimes guess the home state of the motorcyclists they treat. Nebraska obliges all riders to wear helmets; neighbouring Iowa, Kansas and South Dakota do not. The helmetless are distinctive, says Dr Lori Terryberry-Spohr: they suffer “diffuse” internal bleeding and cell death across large areas. Such patients typically run up $1.3m in direct medical costs. Fewer than a third work again. A study of helmet-shunning bikers admitted to one large hospital, cited by the Centres for Disease Control (CDC), found that taxpayers paid for 63% of their care.

During the 2013 legislative session, 19 bills were introduced in 11 states to repeal all-rider helmet laws. None passed. Appeals to thrift can take some of the credit. For years, helmet-advocates stressed human suffering when giving evidence to state legislatures. Now they also stress costs to taxpayers. Libertarians often demand: “Let those who ride decide,” says Jacqueline Gillan, who heads Advocates for Highway and Auto Safety, an insurer-funded lobby group. Her retort is: “Let those who pay have a say.”

When states repeal or weaken motorcycle-helmet laws, as dozens have, helmet use falls, fatalities rise and head-injury hospitalisations soar. Biker deaths rose 18% after Michigan repealed its all-rider helmet law in 2012. A rule obliges unhelmeted Michigan riders to carry at least $20,000 in medical-payments coverage. That does not even cover initial stabilisation in intensive care after a nasty crash.

Helmet-haters claim that increased deaths merely reflect a jump in miles ridden after laws are repealed, as bikers enjoy the wind in their hair. Not so. Some studies measure death rates by motorcycle-miles travelled: deaths-per-bike-mile rose 25% when Texas scrapped helmets, for instance. In Washington Tom Petri, the Republican chairman of the House of Representatives committee that oversees highways, wants the CDC to stop researching motorcycle safety. The agency seems to have “an anti-motorcycle agenda”, he growls. Asked about accidents involving the helmetless, he says: “I don’t think there’s that clear a correlation.”

Earlier this year Dave Bloomfield, a Republican state senator in Nebraska, sponsored an abortive bid to make helmets optional for adults. “We don’t know that there will be more deaths,” he argues, before offering an anecdote about a biker who took a three-state detour to avoid riding through Nebraska in a helmet, depriving the state of his spending on food and fuel. Mr Bloomfield will try again in 2014. Asked directly, he concedes that—personally—he thinks it “silly” to ride a motorcycle without a helmet on the highway. “But government shouldn’t tell people what to do,” he says. How about taxpayers?