Studies on the area are lacking, but we do have a 300k Euro Study mandated by the European Union about it. Most interesting finding on the matter is that the study couldn't actually find correlation between increased piracy and sales, either positive or negative.
Other interesting finding is that piracy is also not dictated by price, at least for music and games.* As follows:
So, while we can't say that piracy is
entirely a distribution problem, it seems like a logical conclusion that it plays a big part in it. But we can't also reliably say that as a study is needed about it.
*in europe
edit: i'm a dumbdumb and forgot the source:
https://cdn.netzpolitik.org/wp-upload/2017/09/displacement_study.pdf