This paper investigates three questions related to endogenous information and knowledge disclosure by firms: Which industry sectors are more apt to disclose information and knowledge? Why is such knowledge released? Is knowledge disclosure an efficient strategy? An empirical analysis on four French data sets that focus on appropriation, the practices of innovation, and the related payoffs suggests answers to these questions. A firm with high R&D intensity, from a high-tech sector, participating in R&D partnerships is found to be more likely to engage in disclosure. Firms in the sample were found to "leak" their knowledge to public laboratories to a greater degree than to other private sector firms. Leakage also was found to be associated with improved innovation performance. This research helps broaden the literature on knowledge management practices to include not only the pursuit of formal intellectual property rights such as patents but less formal inter-organizational knowledge transmission mechanisms.