Abstract
The importance of sustainability in the wine sector has gradually increased in recent years, due to significant pressure from the market, regulators and a changing climate. Given significant investments and risks that wineries face to transition towards sustainable production practices, numerous studies have investigated consumers' willingness to pay (WTP) for sustainably produced wine. Most of these studies focus on the environmental pillar of sustainability, while attention to the social pillar is more recent. In this context, our paper aims to fill an important research gap: no meta-analysis has analysed the WTP for sustainably produced wine, considering social and environmental dimensions as well as differentiating between pure claims, actual practices and certified actions. Our results are heterogeneous indicating a WTP of 15 % (95 CI, 13 %–18 %) for sustainably produced wine based on 146 effect sizes. That is, price premia depend on a number of methodological and substantive moderators, with the latter primarily explaining WTP heterogeneity. Key moderators include the data collection year, the use of certified labels vs generic claims and declarations regarding sustainable practices. To a lesser extent, organic certifications, the study location, respondents' wine consumption frequency and the number of sustainability attributes examined are also influential. Our results can guide researchers in the field to optimize study designs, wineries to valorise their sustainability efforts and policy makers to support the wine sector's sustainable transition.