RESUMO
At the global level, the UN 2030 Agenda for Sustainable Development Goal 14 calls for action to significantly reduce marine litter pollution by 2025. To understand the non-market benefits of removing marine litter, researchers have conducted numerous studies on Willingness to Pay (WTP) for reductions in beach litter. This paper estimates the overall effect size of WTP for a worldwide dataset of 63 primary studies over 22 years by applying a meta-regression technique to assess the variability in WTP estimates. The results show an annual mean effect size of $US0.71 (or $US35.29) per person for a 1 % (for a corresponding 50 %) reduction in all types of beach litter. The observed heterogeneity is associated with WTP elicitation methods, beach attributes, geographic locations, and per-capita income. This study yields valuable information for policy makers to develop cost-effective policies and recommends standardised measurements to benchmark changes in marine litter pollution.