It’s unusual for the expert opinions on an issue to range all the way from zero to 100%.
Economists using an instrumental variable approach found that digital piracy did not hurt record sales in the 2000’s. Hammond (2014) found, incredibly, that file-sharing increased record sales. The picture above is of an article critiquing the Oberholzer-Gee and Strumpf (2007) conclusion that was published by a top journal.
Liebowitz reports that music industry professionals believed that digital piracy was the primary or complete cause of the decline of record sales. One would think that industry insiders have accurate data on the problem and a decent mental model relating the variables together.
The estimated effect of music file-sharing ranged from helping music sales to completely eliminating them. Where else can we find so much disagreement on the answer to a narrow empirical question?
Economist Writing Every Day 