Resumen
This paper searches for the determinants of government-funded R&D. The goal is to disentangle whether the efficiency considerations overwhelmingly emphasized by the theoretical literature are indeed the main driving force behind public R&D expenditures. Another goal of the paper is to assess whether other types of innovation policy such as the degree of patent protection can have an impact on private R&D. I find that there are important differences between rich and poor nations at this respect. In particular, R&D-specific efficiency factors are not significant to explain public R&D in rich nations, whereas related variables such as the access to private credit are important in less developed economies; in rich countries, public innovation effort can be better explained by the political economy variables that determine the size of governments. Private R&D, on the other hand, depends in high income economies on R&D policies not related to direct public innovation effort, but is highly determined by this variable in developing countries. Results suggest that more research on political economy theories of innovation is essential to understand R&D investment.