Legalizing recreational marijuana use in Colorado, Oregon and Washington has resulted in collision claim frequencies that are about 3% higher overall than would have been expected without legalization, according to a new analysis from the Highway Loss Data Institute (HLDI).
HLDI, part of the Insurance Institute for Highway Safety (IIHS), reported in a statement on Thursday that it conducted a combined analysis using neighbouring states as additional controls to examine the collision claims experience of Colorado, Oregon and Washington before and after law changes. Control states included Idaho, Montana, Nevada, Utah and Wyoming, plus Colorado, Oregon and Washington prior to legalization of recreational use, the statement said. During the study period, Nevada and Montana permitted medical use of marijuana, Wyoming and Utah allowed only limited use for medical purposes, and Idaho didn’t permit any use. Oregon and Washington authorized medical marijuana use in 1998, and Colorado authorized it in 2000.
HLDI also looked at loss results for each state individually compared with loss results for adjacent states without legalized recreational marijuana use prior to November 2016.
Data spanned collision claims filed between January 2012 and October 2016 for 1981 to 2017 model vehicles. Analysts controlled for differences in the rated driver population, insured vehicle fleet, the mix of urban versus rural exposure, unemployment, weather and seasonality.
HLDI noted that that collision claims are the most frequent kind of claims insurers receive. Collision coverage insures against physical damage to a driver’s vehicle in a crash with an object or other vehicle, generally when the driver is at fault. Collision claim frequency is the number of collision claims divided by the number of insured vehicle years (one vehicle insured for one year or two vehicles insured for six months each).
“The combined-state analysis shows that the first three states to legalize recreational marijuana have experienced more crashes,” said Matt Moore, senior vice president of HLDI, in the statement. “The individual state analyses suggest that the size of the effect varies by state.”