This is the kind of thing that gives ghostwriters a bad name: Merck wrote the studies for Vioxx and persuaded (or bribed) prominent doctors to sign them.
Perhaps if someone outside Merck had actually conducted and written the studies, the drug wouldn’t have been released unless it was safe, and Merck would have been spared its eventual recall.
There are times when it really does matter whether the person whose name is on a document is the one who wrote it. And there are times when the identity of the ghostwriter matters more than the identity of the author. If obscure doctors had conducted the Vioxx study and more prominent doctors had signed it, this would not have been much different from the common scientific practice of having the graduate students do all the work and the professor get top billing on the publication. It’s the fact that it was Merck’s employees who wrote the studies that invalidates the results.