It is often assumed that voluntary sustainability standards – such as Fairtrade – could not only improve the socioeconomic wellbeing of smallholder farmers in developing countries but could also help to reduce negative health and environmental impacts of agricultural production. The empirical evidence is thin, as most previous studies on the impact of sustainability standards only focused on economic indicators, such as prices, yields, and incomes.

Written employment contracts may improve the conditions of agricultural workers in developing countries, but farmers as employers often prefer less formal oral arrangements. We evaluate whether farmers’ preferences, which are deeply rooted in traditional norms, can be influenced through a group awareness campaign. In a randomised experiment in Côte d’Ivoire, we show that such a campaign increases farmers’ preferences for written contracts and for contract features involving social benefits for workers.