Essays on the economics of research and development.

Summary This thesis studies different aspects of the economics of research and development (r&d). It is particularly interested in industrial research with a commercial goal. The remuneration mechanism that governs this type of R&D is the patent system. The thesis is articulated around two main areas of interest. The first is the analysis of the behavior of firms in the search for and diffusion of innovations. The first part of the thesis, "search for and diffusion of innovations", presents an overview of recent developments in the theoretical literature in this field. It allows to situate the framework of analysis of the second part, "industrial structure and research incentives". This part studies three particular problems: the industrial structure in a patent race when firms face both fixed and variable costs in the research process, subsidies to innovative firms in a perfect information framework, and the form of licensing contracts when information asymmetries exist between buyer and seller. The third part, "labor market of researchers", constitutes the second focus of the thesis. It analyzes the particular characteristics of this market and focuses on two essential aspects: the instability of the researchers' labor market, and the optimal strength of researchers' contracts.