Union participation has held steady for the past 20 years in the Golden State, according to a new report by UCLA and UC Berkeley, despite a national decline since the 1980s.

Opponents of Proposition 22 say the initiative does not guarantee that drivers will receive the 120% of California’s $13 minimum wage because of the hidden costs of app-based driving, such as vehicle upkeep and waiting times between rides. They cite research from UC Berkeley, which indicates drivers would only make about $5.64 under Proposition 22.