Gov. Gavin Newsom (D-CA) has spent the last several years blaming price gouging from oil companies for the high gas prices in his state. Unsurprisingly, it is his own policies that were jacking up prices all along.

Michael Mische of the University of Southern California’s Marshall School of Business looked at gas prices over the past 50 years to determine what caused price increases. He determined that it wasn’t greedy oil executives lining their own pockets but California’s strict regulations, which include environmental regulations that mandate a particular blend of gasoline that is not widely produced, leading to a supply shortage. They also include the Cap-and-Trade Program, which led to prices rising rapidly in 2015, according to Mische, and widened the gap between California prices and the national average.