Adoption and transferability of joint interventions to fight modern slavery in food supply chains

More than 50 million people in the world are estimated to be in a situation of modern slavery, the most extreme form of labour exploitation. Many of them are working in sectors such as mining and agriculture, which produce price-sensitive commodity products and where workers are particularly vulnerable. Against this challenge, we analyse a successful intervention against modern slavery in a place that has been labelled the "ground zero of modern slavery in the US". The Fair Food Programme was established in the tomato growing industry in Immokalee, Florida, and is based on an innovative joint action between farmers, buyers, and workers. We use an agent-based model built on qualitative field data to explain the success of the programme and to investigate whether the programme could be successfully transferred to other contextual settings. We model several market structures and measure the time it takes for all actors in the system to join the Fair Food Programme after a shock event (such as a case of modern slavery being discovered) triggered a dynamic of joint action. Our model shows that a high heterogeneity in farmer sizes leads to an increase in the time taken for them all to join the Fair Food Programme, while a high heterogeneity in buyer sizes speeds up reaching the tipping point towards joint action. We discuss these results and their implications for the transferability of the Fair Food Programme as a voluntary, incentive-driven approach towards tackling modern slavery, to other locations and contexts