In my experience, the pharmaceutical company would pay a communications/marketing company to write the manuscript, who would then go out and find academics who would be willing to become the “authors” of the manuscript and paid an honorarium. I’ve worked with some authors who do absolutely nothing on the manuscript, requiring an additional ghostwriter to be hired, and still demand an honorarium for their time. These academics are willing to enter into this relationship because of the importance of authorship to their careers. You can’t entirely blame the pharma company. Universities encourage academics to play this game.
A ghost writer betrays a little annoyance with some of UD’s fellow professors.