This research evaluates the impact of competition from unregistered firms on R&D investment by formal firms in emerging economies by considering their industrial sector and institutional factors, such as intellectual property rights. We performed a study using the propensity score matching approach and the World Bank Enterprise Survey of 16 Latin American emerging economies. We observed that the R&D investment response of formal firms varies according to the typology of industrial sectors. Supplier-dominated industries reduce investments in R&D when confronted with the informal sector. However, science-based, specialized suppliers and scale-intensive industries do not alter their investments. In addition, the level of intellectual property (e.g., IPRI) modifies the effect of the informal sector on R&D investment. Formal firms reduce their investments in R&D when the IPRI environment is underdeveloped. This reduction does not occur in highly developed IPRI environments. We also discuss the finding's theoretical and practical implications and suggest avenues for future research.