Ghost writing is something that has happened for years in literature. Nancy Drew is a prime example, otherwise Carolyn Keene has been writing for more than eighty years. In the case of pharmaceutical publications, they seem to be capitalizing on the idea that major researchers do not always write their own papers. How many times has the seventh or eighth author down written the paper and the primary author has only edited it or added characteristic flourishes? In the case of a small research groups, the second author may have done all the work but the primary investigator has a bigger name and so is credited with the writing of the paper and the design of the study, even though he or she may have done nothing and left it all to the assistants on the project. This probably happens more than the public knows or would like to consider.
The pharmaceutical industry, while the practice is unethical, seems to be following in the trend of other research groups. Again, in order to restrict pharmaceutical companies from doing this there would have to be restrictions placed on a great number of researchers and in other industries as well (Tom Clancy has not written a splinter cell book for years). Not only this, but there would be several researchers in various disciplines that would be discredited because of this practice and then there would be a lack of information available in the market.