5. Discussion, implications, and future research
In this paper, we focused on how the breadth of external knowledge sourcing affects product innovation and, more specifically, whether the implementation of two strategic HR practices (heterogeneous work groups and brainstorming) influences this relationship. On the basis of data from the Italian Innovation survey, we confirm the inverted U-shaped relationship between external search breadth and product innovation. We ascribe this finding to theories suggesting that broad searches increase creative thinking and recombination possibilities (e.g., Laursen, 2012, Leiponen, 2012), which ultimately facilitate the introduction of innovative products. However, after a certain level of external search breadth, those benefits are outweighed by the increasing complexities inmanaging different search channels, defining the better time when exploiting certain knowledge components, and allocating attention to each knowledge source (Koput, 1997; Laursen & Salter, 2006). In addition, the NIH syndrome is likely to hamper the knowledge acquisition process needed to support internal product innovation activities (Katz & Allen, 1982). Furthermore, we revealed that the negative returns of external search breadth occur later if companies implement heterogeneous work groups and brainstorming sessions. In particular, we indicated that heterogeneous work groups can limit the drawbacks of searching broadly owing to the specialization of labor and a depth understanding of various knowledge domains (e.g., Shin et al., 2012; Stock et al., 2014). Brainstorming is instead important because it gives rise to cognitive facilitation, favors long-term planning, increases people's commitment to knowledge sourcing, and makes group members more open-minded (e.g., Andriopoulos & Gotsi, 2006; Hollins, 1999; Paulus et al., 2011).
