“…As such, it has been assumed that as a result of spatial proximity among firms, a thematic geographical cluster stimulates collabo-ration and innovation (McCann and Folta, 2011;Katz et al, 2015). However, there is evidence that even in micro-scale settings specifically developed to foster inter-firm networks, such as university business incubators (UBIs), professional relationships between firms do not develop automatically or easily (Cooper et al ., 2012;Fuzi, 2015;Parrino, 2015). Furthermore, it seems that even when business relationships do develop, firms rarely exchange valuable resources with various parties (Soetanto and Jack, 2011) and seldom formalise their collaborations (McAdam and Marlow, 2008).…”