This study analyses the bidirectional relationship between economic growth and the efficiency of research and development (R&D) expenditure in five Latin American economies: Colombia, Chile, Brazil, Mexico, and Argentina. Annual series from the Science and Technology Indicators Network (RICYT) were used for the period 1990–2022, applying unit root tests (ADF, Phillips–Perron), Granger causality models, VAR/VECM, ARDL/ECM, and simultaneous equations (2SLS/3SLS). The variables included gross domestic product adjusted for purchasing power parity (GDP PPP) and two efficiency indicators: publications and patents per unit of R&D expenditure. The results show significant reciprocal causality in Colombia and Chile, partial relationships in Brazil and Mexico, and unstable effects in Argentina. The estimates reveal positive and significant elasticities in both directions, with an effect of 0.2–0.3% of GDP for 1% increases in expenditure efficiency. These findings confirm the existence of a dynamic, endogenous equilibrium between knowledge and growth, though it is conditioned by institutional maturity and expenditure orientation. The study contributes to the academic debate on endogenous growth by introducing a measure of knowledge efficiency that combines scientific and technological productivity, demonstrating that the quality of R&D expenditure is more decisive than its magnitude.
Campo et al. (Thu,) studied this question.