"Second, except for the pharmaceutical industry, patents are not necessary to increase incentives to innovate (most firms would invest a similar amount in R&D without the existence of the patent system). Third, the use of patents is strategic (defensive use, signaling, knowledge management, etc.). In conclusion, most empirical studies question the global positive effect of patents on incentives to innovate (see Bessen, Meurer, 2008, for a survey). This conclusion is robust according to the different methodologies used, such as a questionnaire-based inquiry (Mansfield, 1986; Levin et al., 1987; Cohen et al., 2000), natural experiments (Sakakibara, Branstetter, 2001; Lerner, 2002), or, more recently, lab experiments (Meloso et al., 2009)."

That first sentence, which is the crux of our disagreement, does not have a citation. If I had more time, I would like to read a few of those studies mentioned at the end of the paragraph, but until I do, I'm not convinced!

Also, this: "First, patents are not the most efficient instrument to protect an invention (secrecy, lead time, complementarity with other assets, are usually preferred)." As others have mentioned, if you take away the patent system, of course everyone will try to protect their inventions by secrecy. Is that what we want? I don't think so. Also, I have no idea what he means by "lead time" and "complementarity with other assets."

Skimming through the entire paper, I agree with just about everything it says. I agree with this in the conclusion: "
This paper emphasizes the importance, but also the dangers, that the patent system can entail for the process of open innovation. Paraphrasing Zobel et al. (2016), whether or not patents enable or hinder open innovation is still to be established, but this issue is crucial for both policy and management, as innovation becomes systemic—that is, innovation is increasingly dependent on knowledge exchange and collaboration."