The promotion of regional or minority languages (RMLs) has long been confined to culturalist, legal-institutional, or pedagogical perspectives. These perceptions have started to change in the early 1990s, with increasingly frequent reference to economic arguments. This chapter proposes a critical examination of these arguments and assesses their respective robustness. While they are not mutually incompatible, their respective relevance depends on context, and the paper proposes an approach to the appropriate selection of arguments in RML policy.