One of the more heated topics in the motorcycle world is the subject of helmets.

States across the country spend much political time and capital on adding or reversing mandatory helmet laws with the usual cast of characters lining up either side of the debate.

But a series of studies is adding weight to those who say having a mandatory helmet law just makes financial and moral sense.

Motorcyclists in states that require all riders to wear helmets are less likely to file insurance claims for medical treatment after collisions, compared with riders in states without helmet laws or where the laws apply to some but not all riders according to the findings of a new study by the Institute-affiliated Highway Loss Data Institute (HLDI).

Twenty states require all motorcyclists to wear helmets, 27 target the laws at younger riders, and 3 states (Illinois, Iowa, and New Hampshire) don’t have helmet laws at all. HLDI compared the risk of injury claims, given collision claims, for riders in these groups of states, finding the lowest risk under the universal laws. Injury risk was 3 percent higher in states with laws applying to some riders and 6 percent higher in states without helmet laws. Injury risk was 4 percent higher among riders older than 21 in states where these riders aren’t required to wear helmets.

The study includes collision and medical payment claims data associated with 2001-09 model motorcycles involved in crashes in all but a few states during 2002-09. Collision coverage, which insures against damage to a motorcycle, generally applies when a rider is at fault. Medical payment covers the medical costs of injured riders up to policy limits. Overall, more than half of collision claims resulted in associated medical payment claims. HLDI’s database doesn’t include information about the types of injuries associated with such claims or whether riders were wearing helmets when they crashed.

Helmets are the principal countermeasure for reducing head injuries, the leading cause of death among unhelmeted riders. They reduce the likelihood of death by 37 percent. Without them, motorcyclists are 3 times as likely as helmeted riders to suffer traumatic brain injuries. Yet many motorcyclists refuse to wear a helmet if it’s not illegal to ride without one.

Nearly all riders wear helmets in states with universal laws, but requiring helmets on some riders doesn’t boost use rates or rider safety nearly as much. Helmet use is about half in states that don’t have helmet laws or that apply their laws only to younger riders.

Universal helmet laws aren’t popular, but they’re effective concludes the Insurance Institute for Highway Safety in a recently released study. Nearly all motorcyclists always wear helmets in states where the laws apply to all riders, but only about half do in states with no laws or laws that apply to some riders, usually younger ones.

“It’s encouraging that the youngest riders in our survey were the most likely to recognize the benefits of helmets and express support for universal laws because these riders typically are the biggest risk takers,” Anne McCartt, Institute senior vice president for research says, “Baby boomers appear to be the hardest to reach, which is worrisome because they’re the biggest group of riders today.”