Under what conditions do courts implement mechanisms of social participation in judicial decision-making? Over the last two decades, Latin American constitutional and supreme courts have been opening themselves up to the public through institutional innovations such as public hearings and the acceptance of amicus curiae briefs. This paper analyses such court behavior from a comparative perspective. Theoretically, we argue that the implementation of these mechanisms requires both the presence of a court composition that values openness (ideational factors) and the contextual incentives to use them (with strategic considerations). Our empirical analysis consists of three steps: First, to assess the frequency of use and influence of the mechanisms in practice, we designed an expert survey and implemented it in 10 Latin American countries during the course of 2022. Second, three in-depth studies of Argentina, Ecuador, and Uruguay allowed us to explore the causal relationship between the conditioning factors and the degree of court openness. Third, we briefly evaluate the impact of court openness on trust in high courts. Only the consistent and regular use of social-participation mechanisms can help to improve trust, and our empirical analysis shows that this has only happened in the case of Colombia.
