Public policies to encourage innovation: evaluation of their impacts in static and dynamic analytical frameworks.

Summary The role of innovation and technical progress in economic growth explains the interest of public authorities in encouraging private firms to innovate. On the other hand, the innovation process has some characteristics that are not conducive to private investment and that partly justify public intervention. The purpose of my thesis is to study the different means available to public authorities to encourage firms to invest in R&D (patent system, research subsidies, cooperation agreements). The first chapter of the thesis is devoted to a quick review of the economic literature on these topics. The second chapter studies the question of the social utility of a patent system as an instrument of knowledge diffusion and as a means of appropriating research results. The last chapter takes up the question of the utility of the three instruments but this time assuming that the different instruments can be used simultaneously.