Plastic bag regulations aim to reduce plastic pollution, yet evidence on long-term behavioral responses remains limited beyond California. This study uses NielsenIQ retail scanner data (2010Ð2020) across 30 US counties to examine the generalizability and persistence of changes in consumer spending on unregulated plastic disposal bags. Using two-way fixed effects, Callaway and SantÕAnnaÕs staggered DID, and synthetic DID, we find that plastic bag regulations increase spending by 55%Ð68% for waste bags and 2%Ð11% for tall kitchen bags, while heavy-duty bags show no consistent change. Results hold under robustness checks that exclude California, include placebo treatments, and use alternative specifications.