MSU Study Of Graduated Driver Licensing Laws Illustrates Shift In Field Of Economics

When Gregory Gilpin was getting his first driver’s license in 1992, the process was pretty simple. There was a 20-question multiple choice test to get a permit. After a month, he went back, took a driving test and got a full unrestricted license.

“That’s very different from today,” said Gilpin, head of the Department of Agricultural Economics and Economics in Montana State University’s College of Letters and Science and College of Agriculture.

Teens are now subject to states’ individual graduated driver licensing laws. Gilpin said there are nine main provisions of these graduated licensing programs enacted across the United States, including supervised driving hours, grade-based driving privileges and extra restrictions on passengers or nighttime driving. State driver licensing laws differ in which provisions they incorporate, yet overall these programs have been credited with the substantial 69 percent decline in traffic fatalities involving 16- to 17-year-old drivers in the U.S. over the 20-year period from 1996 to 2015, he said.

While past studies have shown these provisions do reduce traffic fatalities among teens, in large part by keeping them off the roads, they have mainly focused on graduated driver licensing as a whole without breaking it down for each type of provision. Gilpin, a father of four who studies youth and risky behavior, wanted more detail. Of Gilpin’s four kids, three are teenagers — two are licensed drivers and the third is soon to be. Which provisions would actually make teens like his safer?

“The economics of it comes down to our most precious resource — which is people,” Gilpin said.

Gilpin said his study, “Teen Driver Licensure Provisions, Licensing, and Vehicular Fatalities,” published in the Journal of Health Economics, is part of a larger movement in the field to dive deeper into public policies and how they affect people’s lives.

“I think we’ll continue to see these types of analyses coming out of our department and the economics profession,” he said. When Gilpin looks back at his high school years, he can’t help but recall an incident in which a group of teens in his class had been out drinking one night when the Jeep they were in went off the road and rolled, killing one of the boys.

“I was profoundly impacted,” Gilpin said. “Maybe public policy can reduce these negative impacts on youth.”

His native Ontario, Canada, was one of the first places to enact graduated licensing laws.

Gilpin’s national study combines data from the Fatality Analysis Reporting System, the Federal Highway Administration and the U.S. Census Bureau to look at all teen driving fatalities in the U.S. from 1996 to 2015. Data exists for every year, state, gender and age group, Gilpin said. Historical data from the Insurance Institute for Highway Safety allowed Gilpin to pinpoint when each state enacted each provision to compare teens behavior in states before and after they go into effect. While the existing literature around driving fatalities tends to use only the death of the driver as a measure, Gilpin said his research is broader. It includes any fatality occurring with the teen driver, including pedestrians and occupants of other vehicles involved in the crash. Gilpin also took into account the overall decline in traffic fatalities over all age groups attributed to automotive technology, roadway safety and health care improvements.

Provisions Gilpin studied included learner’s permits, supervised driving hours, raising the minimum age, restrictions on passengers or nighttime driving, cellphone or texting bans and tying licensing to passing grades.

One of the provisions — stipulating the number of supervised driving hours required before getting a full license — was actually linked to a 6 percent increase in fatalities. Gilpin said this suggests that requiring supervised driving hours may put teen drivers into challenging driving scenarios too early. Building on existing research that shows teens who have not completed drivers’ education are 24 percent more likely to be involved in a fatal or injury accident, Gilpin said the negative impact of stipulating supervised driving hours is mitigated if teens can satisfy a large portion of those hours with a licensed drivers’ education instructor rather than parent or other adult in the car.

“It’s not the number of hours, but rather the instructor in the vehicle that makes the difference in fatalities,” Gilpin said.

More is not better when it comes to the number of provisions, and piling all of them on a young driver will not help reduce the possibility of a fatal crash. Gilpin said his study did identify one provision that has the largest impact: raising the median age to obtain an intermediate license to 16 ½. Before this age, he said, teens do not have the maturity and brain development to safely operate a vehicle.

“You have to have a specific amount of competence and maturity and skill,” he said. “Older drivers are safer, even in their first year of being licensed.”