Patent citations, knowledge flows and catching-up: evidences of different national experiences for the period 1982-2006

The investigation comprises information about patent citations distributed by different technological domains, which are used to map knowledge flows and to correlate these flows with the evolution of countries' competences. Specifically, the analysis uses information about patent citations to track and discuss the evolution of knowledge flows to a set of selected countries involved in catching-up up processes.. The analysis comprises an analysis of patent citation data extracted from the USPTO database from the period 1982-2006, including information about citations extracted from patents granted by national companies of the selected countries, presented trough technological interaction matrices crossing information of different technological domains of the patents, correlating the technological domains of the patents citing other patents with the technological domains of the patents cited. The hypothesis is that the intensification and diversification of knowledge flows to a greater number of fields broadens the possibilities of identifying attractive opportunities for innovation, magnifying the possibilities of development and catching-up. The analysis tries to identify which technological fields concentrate the absorption and diffusion of knowledge in a given country along different periods, which tends to be connected to the possibilities of catching up processes.