Piracy may the opposite effect for software but it definitely has a negative effect on entertainment related IP. High school events where I grew up were basica

Piracy may the opposite effect for software but it definitely has a negative effect on entertainment related IP. High school events where I grew up were basically an iMac with the student body officers' MP3 collections and a PA system. All the pirated MP3s people were playing at those various official and unofficial gatherings of my youth led to me buying CDs once I had money of my own. Has a non-industry-affiliated research group produced causal data (not just declining sales figures) showing that noncommercial entertainment piracy is a net harm?