This chapter compares the authority of the Central American Court of Justice (CACJ) and the Caribbean Court of Justice (CCJ) with that of the Andean Tribunal of Justice (ATJ) and the Mercosur Permanent Review Court (PRC) and, in so doing, draws general conclusions about the actors and factors that may be deemed of importance for better understanding the de facto authority of the Latin American and Caribbean Regional Economic Courts (RECs). More specifically, it shows that, similar to the CCJ, the ATJ has been relatively successful in achieving authority, at least in the area of intellectual property (IP) law. This occurred thanks to the Court’s ability to develop a relationship with state and sub-state actors, such as administrative agencies and national judges, which repeatedly filed preliminary rulings on these topics, thus allowing the Court to make a difference in this area of law. The chapter also shows the fluctuations of the authority of the ATJ on classic matters of community law, such as removal of trade barriers and the implementation of the policies of the Andean Community. In contrast, the Mercosur PRC has struggled throughout its history to ensure that it receives a steady flow of cases to rule upon and has been repeatedly criticised by both state and sub-state actors. This final chapter shows that this reality is a symptom of political instability, lack of commitment to regional institutions, authoritarian politics, and struggle to complete the transition to democracy in the Mercosur Member States. Against this background, the chapter draws general theoretical conclusions on the authority of the four RECs in Latin American and the Caribbean.