By Benjamin Oreskes

A California law giving immigrants here illegally the ability to get driver's licenses appears to have helped decrease hit-and-run accidents, according to a Stanford University study released Monday.

The controversial law, part of a larger effort by state officials to provide rights and services to California residents in the country illegally, resulted in more than 850,000 people getting driver's licenses since the law took effect in 2015.

Supporters of the measure argued that it would make California roads safer because those here illegally would be forced to take driver's tests and would be less likely to flee from accidents out of fear of being arrested or deported.

The Stanford study estimated that the rate of hit-and-run accidents decreased at least 7 percent in 2015 compared with 2014. Using a complex formula, the researchers concluded that there were 4,000 fewer hit-and-runs that year because of the new law.

The Department of Motor Vehicles would not release data on who got the new licenses on a county-by-county basis. So the research team of Hans Lueders, Jens Hainmueller and Duncan Lawrence had to estimate how many new licenses in each county were given to people here illegally.

Hainmueller, a political science professor, said in an interview that the team looked at driver's licenses issued in the years before the law took effect. In 2015, the number of licenses issued in certain counties with large populations of people here illegally jumped dramatically. They then compared those data to hit-and-run records in those counties and determined they had decreased.

This marked the first time researchers had tried to measure the effects of this policy change.

"We were really interested in part because California is not the only state to have implemented this law," said Lawrence, another study author and a political science researcher.

The license is intended for people who cannot show proof of legal resident status in the United States. This license though has limits. For example, a Californian couldn't use an AB60 license to board an airplane or cross into Canada.

There are 12 states and the District of Columbia with similar laws on the books. Hainmueller pointed out that New York state is currently debating a similar bill, and that the debate there is occurring without much evidence about whether these laws are helpful.

"It's shocking to see how you have these controversial debates and everyone is flying blind in terms of evidence," Hainmueller said. "People in favor of it love it, and people against immigration hate it."

Researchers posited that this new law would give people who may have been driving without a license a new confidence about being on the roads. Before, if they had been in a fender-bender, they may have been worried about waiting for authorities to arrive. These results suggest "that, if anything, providing unauthorized immigrants access to driver's licenses reduced their incentives to flee the scene of an accident," the authors of the study write.

The study finds that this reduction in hit-and-runs had a marked economic benefit. "Because AB60 led to an annual decline in hit and run accidents by about 4,000, not-at-fault drivers avoided out of pocket expenses for car repairs (physical damage) of about $3.5 million," according to the researchers.

That's on top of $17 million per year that they estimate would be transferred to the at-fault drivers' insurance. That's the cost, which in case of an accident, would be levied on the responsible party. In the past a hit-and-run victim's own insurance providers would've had to pick up the tab on this expense.

"We think the law should lower premiums for California drivers because you're moving the payments to at-fault drivers," Lawrence said.

(c)2017 Los Angeles Times