A study from IFPI The Effect of Graduated Response Anti-Piracy Laws on Music Sales: Evidence from an Event Study in France” (SSRN record). Four major record labels (Universal, Warner, EMI and Sony Music) supplied music sales data. Scientists from American Universities analysed the French data. It is insightful that the effect is mostly psychological. The mere enactment of the Hadopi law is perceived as a signal to consumers. The study “does not quantify the entire effect of HADOPI on producer surplus in the media industries, but merely indicates that for one industry (music) in one channel (iTunes), the law has had a large and statistically significant effect.”