Doit-on réguler l'appropriation des connaissances ?

In this work, we propose to look at the stock of knowledge that can be patented by private labs. We consider this stock as a common. It changes over time according to the number of patents and to a by-product of the University research activity. We first show that the competition between strategic labs generate, in the short run, an over-extraction of the stock of knowledge. This reduces, in the long run, the patent activity. We finally show that the taxation of patents is an efficient tool in order to regulate the knowledge privatization process.