Sharif Digital Repository

The evolution of innovation system literature is scrutinized to delineate the conceptual trends over the past 30 years. We applied the Sigma index which is supposed to include not only the frontier contributions in the field but also the intellectual bases conveying transformative concepts. Our examination shows that after the establishment of the National Innovation System (NIS)as a principal framework, Regional IS literature emerged as a main branch during the period of 2002–2007, while Technological IS developed as the second main branch from 2007 to 2012. Surprisingly, Sectoral IS has not yet generated a separate constellation, whereas the period after 2012 mainly witnessed the emergence...