OREANDA-NEWS  A law giving special driver’s licenses to unauthorized immigrants in California did not increase the rate of total accidents or fatal accidents, according to a study of more than 800,000 such drivers. It has also helped reduce the likelihood of hit-and-runs.

The plan to grant special driver’s licenses to unauthorized immigrants prompted arguments that the law could damage immigration enforcement and lead to unsafe roads.

“Coming to this as scientists, we were immediately shocked by the absence of facts in this debate.”

“Coming to this as scientists, we were immediately shocked by the absence of facts in this debate. Nobody was drawing on any evidence; it was more characterized by ideology,” says Jens Hainmueller, professor in the Stanford University Graduate School of Business and co-director of the Stanford Immigration Policy Lab, which focuses on the design and evaluation of immigration and immigrant integration policies. “There was no real evidence of the likely consequences.”

For the study, published in the Proceedings of the National Academy of Sciences, researchers narrowed in on traffic-safety outcomes because they found it was the most prominent issue when such licensing policies are discussed.

Opponents “are concerned about potential increases in accidents, or whether those accidents may encourage drivers to run away, but we didn’t find evidence of the causative effects,” says graduate fellow Hans Lueders, a PhD student in the Stanford political science department. “That’s how we determined this would be the most salient issue and the easiest to measure immediate effects, because not that much time has passed since the law was enacted.”

The researchers combined data from two sources to estimate the short-term effects of AB60. They examined monthly data on accidents from the Statewide Integrated Traffic Records System of the California Highway Patrol and that were collected between 2006 and the end of 2015. They also looked at data from the California Department of Motor Vehicles on all outstanding licenses before and after the implementation of the law to estimate the share of each county’s AB60 licenses.

The data suggest AB60 led to an average decrease in the rate of hit-and-run accidents of between 7 percent and 10 percent in 2015 over 2014. That translates to about 4,000 fewer hit-and-run accidents in California in 2015 due to AB60.

“We don’t find a negative effect at all. It suggests these policies can have positive effects on traffic safety. If drivers at an accident remain on the scene, they can be held responsible and pay for the damage,” Lueders says. “This amounts to more than $17 million attributed to the at-fault driver.”