“…Looking at the input and output additionality of cluster policies, and more broadly of innovation network policies, is the most common form of evaluation undertaken in the literature (Sakakibara, 1997;Branstetter and Sakakibara, 2002;Hottenroot and Lopes-Bento, 2014;Bellégo and Dortet-Bernadet, 2014;Brossard et Moussa, 2014;Braune et al, 2016). This kind of assessment essentially consists in estimating additional inputs (primarily R&D expenditure and human capital) and comparing the outputs (economic growth, productivity, patents, etc.)…”