The present paper analyzes the effect of regional specialization and R&D expenditures on labor productivity growth. Following Fingleton [Environ Plan 32:1481-1498 2000], we assume positive externalities in labor productivity growth and technological spillovers depend on interregional distances and economy size. Regional specialization and R&D expenditures are assumed to enhance growth by affecting the level of technology. Although it may seem natural that specialization and R&D expenditures can convey great advantages on economic growth, evidence varies across sectors. We conduct an empirical analysis for two economic sectors and the economy as a whole. Recently developed spatial econometric methods are adopted to control for potential heteroscedasticity in the growth equation.