Evaluating plastic bag levies: A systematic review of behavioural, regulatory, and normative pathways

Single-use plastic bags remain a critical contributor to plastic pollution, with ecological impacts ranging from terrestrial litter to marine ecosystem degradation. In response, governments worldwide have introduced financial disincentives, regulatory restrictions, and educational campaigns to curb their consumption. However, the relative effectiveness and sustainability of these interventions remain contested. This systematic review followed PRISMA 2020 guidelines. A comprehensive search was conducted in the Web of Science Core Collection using the Boolean string (“levies” OR “charge”) AND (“single-use plastic” OR “plastic bag”), yielding 2445 records. After applying filters for publication year (2007–2025), article type, and English language, 10,496 records were screened. A total of 136 full-text articles were assessed for eligibility, 16 met the inclusion criteria. Findings revealed that economic instruments, particularly levies and charges, consistently produced the most substantial reductions in plastic bag consumption. Regulatory and campaign-based approaches improved awareness but lacked durability unless coupled with financial disincentives. Educational and social-norm interventions reinforced pro-environmental behaviours, amplifying compliance and long-term sustainability when integrated with levies. Overall, multi-layered strategies combining economic, regulatory, and cultural levers were the most effective. Economic instruments are necessary but not sufficient on their own. Integrated approaches by pairing charges with enforcement, education, and social-norm reinforcement to offer the greatest potential to reduce plastic bag use and align with global sustainability goals.