While I appreciate the time put into the article this is all speculation. Reality is most companies simply look at the average industry salary and pick that number as an offer. If the candidate doesn't accept it、 companies simply look elsewhere. End of story. Most companies are not that miserable to find new employees even when there is a labor shortage.
The only exception I can think of is being an expert of a specific field. But then again、that specific experience cannot be generalized for the simple reason that it is a SPECIAL case.