Breadth of external knowledge search in service sectors

Purpose There is a dearth of empirical research on the impact of external knowledge search on innovation performance in different categories of service firms. This study explores the effectiveness of the breadth of external search on product and process innovations in German firms. In particular, the author modelled a non-linear relationship between the breadth of knowledge and product and process innovations. Design/methodology/approach Drawing on the Mannheim Innovation Panel (MIP) data for the German service firms in the period 2014–2016, the author reported findings from a bivariate probit model which took into account mutual interdependence between product and process innovations. Moreover, the model was separately estimated for knowledge-intensive business services (KIBS) and other services. For comparative purposes, the author also estimated the model for manufacturing firms. Findings Empirical findings uniformly indicated an inverted U -shaped effect of the breadth of knowledge on both product and process innovations. Furthermore, the results demonstrated that using up to three knowledge sources increases the probability of a joint implementation of product and process innovations. These findings hold for both KIBS firms and other services. However, those service firms that focussed on a single type of innovation experienced diminishing returns to external knowledge when exploiting more than one source of knowledge. These results indicated that a simultaneous introduction of different types of innovation required diverse knowledge sources. In contrast, when focussing on a single type of innovation, service firms experienced diminishing returns when multiple sources were used. However, this finding was only partially found for manufacturing firms. Accordingly, this study’s findings provided support for the demarcation approach, insofar as the breadth of knowledge had a heterogenous impact on innovation in manufacturing relative to service firms. Originality/value Previous studies on the breadth of knowledge search mostly examined its influence on innovation performance without separately analysing manufacturing and service firms. The present study focussed on service firms that were further divided into KIBS and other service firms. By investigating potentially non-linear relationships between knowledge breadth and product and process innovations, it illustrated how different innovation strategies were affected by a diverse pool of external knowledge sources.