Abstract
Purpose
Inter-firm collaborative innovation typically requires knowledge sharing among individuals employed by collaborating firms. However, it is also associated with considerable risks, especially if the knowledge sharing process is not handled using proper judgment. Such risks have been acknowledged in the literature, but the underlying empirical evidence remains unclear. This study aims to examine how sharing of business-critical knowledge with external collaboration partners affects firm’s innovation performance.

Design/methodology/approach
The authors develop a mediating model and hypotheses predicting that the uncontrolled sharing of knowledge leads to accidental knowledge leakage, which, in turn, hinders particularly firm’s radical innovation performance. The authors test the model by using a survey of 150 technology-intensive firms in Finland and a partial least squares structural equation model. The mediating model is tested with incremental and radical innovation performance, and the authors control for firm size, age, R&D intensity and industry.

Findings
The authors find strong support for the model in that uncontrolled external knowledge sharing leads to accidental knowledge leaking and to lower radical innovation performance. The same results are not found for incremental innovation, implying that uncontrolled knowledge leakage is especially detrimental to radical innovation.

Originality/value
These findings help in better understanding some of the downsides of too much openness and lack of judgment about knowledge sharing beyond the boundaries of the firm. Thus, firms pursuing radical innovation should carefully guide their employees with regard to what knowledge they share, to what extent they share it and with whom they share it.