The Researchers say: “Consistent with theoretical predictions, our econometric results indicate that the Hadopi law has not deterred individuals from engaging in digital piracy and that it did not reduce the intensity of illegal activity of those who did engage in piracy” adding “While several factors affect the perceived probability of detection under the law, our results show that the propensity to engage in illegal file-sharing is independent of these beliefs.”
The results suggest that those who have more 'pirates' in their social networks switch to alternatives, such as direct download sites and newsgroups with the researchers saying “There is evidence that the law encourages Internet users who better understand the law and alternative piracy channels (those with many digital pirates in their social network) to substitute away from the monitored P2P channel and to obtain content through unmonitored illegal channels,” which conversely means that the three-strikes system is more likely to catch less prolific file-sharers.
That said, the authors cite another 2014 study which found that iTunes has seen a 20-25 percent increase in sales of French music just prior to implementation of the law. However, the authors attribute the increased sales to "public educational efforts," not to the deterrent effect of the law.
More on http://torrentfreak.com/three-strikes-law-does-nothing-to-curb-piracy-research-finds-140122/ and you can download the paper here