You have a few different issues with the assumptions in your comment.
First, yes, one can ask for a source without a sincere request for it, known as sealioning. However, that was not what I was doing, because:
> While statistical data is much better then common sense reasoning, it's still possible to make claim via deduction and even anecdotal evidence.
Oftentimes, intuition is not correct. Think for example to the Monty Hall experiment where many people thought that the odds of two doors holding the winning prize, after a third door were opened, to be 1/2. However, on actual examination and statistical analysis, it is actually 2/3.
Similarly, simply because you believe that ebook sales reduce print book sales intuitively does not mean that this be so. In fact, based on other studies, it seems that piracy actually increases sales [0].
> Anecdotally if I see a book I like, the first thing I do is google for that book with a ".epub" or ".pdf" extension so I can download it for free. I figure other do-gooders are going to pay for the book so I might as well freeload a free version. It's logically the most cost effective move.
Second, just because you pirate does not mean everyone does. Ebook sales have overtaken print sales, showing that most consumers actually do not pirate. Those that do an action overestimate the percentage of others who also perform that same action, this is a known cognitive effect.
All in all, you have no source except intuition that can be shown to be wrong.
[0] https://www.cbc.ca/news/science/e-book-piracy-may-have-unexp...?