I'm more concerned about the graph attributed to flatworldknowledge.lardbucket.org. I've lived on the internet long enough to know a shitposter when I see one and that's a whale of a URL that every fiber of my body says never to click. I know it is a logical fallacy to dismiss an entire argument simply by association with a crank, but that's my gut reaction to that post.
... I didn't even notice the name. That site is an archive of a collection of textbooks that were Creative Commons-licensed before 2012, dedicated to the memory of Aaron Swartz. Evidently https://2012books.lardbucket.org/books/beginning-economic-an... goes to the same place.
wait, are you saying they actually don't or is this some form of sarcasm? because the link clearly shows, to me at least, that they document the methods publicly