Public preferences for food waste anaerobic digestion facilities: A choice experiment analysis from South Korea

As countries pursue decarbonization, food waste management has become a growing policy priority. Anaerobic digestion enables the biogasification of food waste while simultaneously generating renewable energy and environmental co-benefits. This study examines the preferences of South Korean residents for food-waste biogas facilities using a choice experiment administered to 521 households through a stratified online survey. A mixed logit model was employed to analyse the choice data and estimate marginal willingness to pay while capturing unobserved preference heterogeneity. Results show strong preferences for electricity generation and salient environmental co-benefits—such as emission reduction and improved energy self-sufficiency—with industrial zones and urban outskirts preferred over agricultural areas, reflecting a clear urban-oriented siting preference. Quantitatively, electricity generation received the strongest marginal valuation (MWTP 205.9 KRW/year), followed by notable preferences for emissions reduction and improved waste-processing efficiency. Concurrently, disposal cost emerged as the dominant determinant of choices, and substantial heterogeneity across siting and environmental attributes revealed a distinct behavioural hierarchy in residents' preference structure. Scenario simulations further show that combining non-agricultural siting with salient co-benefits can maintain public support even under higher disposal costs. The findings highlight the need to align food waste anaerobic digestion system design with residents’ preference structures to ensure socially acceptable and feasible deployment in land-constrained and energy-import-dependent countries such as South Korea.