Openness and environmental innovation: Does time-horizon matter?

The antecedents of environmental innovation and the impact of openness on technological innovation have been well studied, yet the role of external knowledge search remains largely unknown. This study explores whether six dimensions of open search (external R&D, acquisition, R&D cooperation, and three types of external information sourcing) enhance firms' environmental innovation (EI) when used either sporadically or persistently. It shows that the temporal dimension of openness matters. Persistent open knowledge search efforts are associated with a firm's propensity to introduce EI, more so than sporadic search. Furthermore, the different types of knowledge search have heterogeneous effects on different types of EI. It also shows that persistent innovation is more relevant in the case of radical EI.