This study measures the total factor productivity (TFP) of 15 OECD countries in the period 19892004 and disaggregates it into its two components: technical change and efficiency change. Subsequently, two theoretical models are estimated to evaluate the effects that technology and institutions have on technical change and on efficiency change. The results show that technology, proxied by domestic R&D stocks or by patents, stimulated the variation in technical change and in efficiency change. In contrast, the reduction of entry barriers and of the relative weight of publicly owned companies, or deregulation in the telecommunications sector, drove technical change but, at the same time, slowed efficiency change.