Environmental policy behavioral spillovers: The impact of California's single‐use carryout bag ban on the use of unregulated single‐use plastics

Abstract This study examines the spillover effect of California's 2016 single‐use bag ban (SB 270) on unregulated single‐use plastics (SUPs) like cutlery, cups, and plates. We observed an insignificant 4.8% decrease in SUP sales over the entire post‐policy period, but a larger 8.1% drop in the second post‐year, which was only marginally significant. The findings suggest weak spillover effects from such environmental policies, indicating that direct regulations on certain environmentally harmful products might be more effective if jurisdictions aim to prohibit citizens from excessive use, rather than relying on the positive spillover effect from existing policies.