Stability in national patterns of technological specialisation: some historical evidence from patent data

The paper examines the evolution of technological specialisation in a group of selected countries over the periodo between 1890 and 1990. Technological specialisation of each countre is measured by the RTA (Revealed Technological Advantage) index, based on patent statistics, in four different historical periods. Following an evolutionary approach, the hypothesis of cumulativeness and of incremental change are tested with a linear cross-section regression model. The results from regression and statistical tests enable some conclusions to be drawn. Path-dependence and cumulativeness in countries' profiles of technological specialisation occurs over a 25-year period. Over longer periods, the size of countries and their ability to either specialised in some niches or broaden out the specialisation across more sectors matters. Diversifying incremental change has found to be a consistent and strong phenomenon among countries, due to countries' natural tendency to move into related technological fields.