It certainly shouldn't happen, but might happen at some places. It would be very suspicious if the same person's name appeared on, say, 100 patents filed within a few years of one another, and that person was a departmental manager.

Inventors' dates of birth aren't on patent applications. To carry out the research, the authors of http://www2.itif.org/2016-demographics-of-innovation.pdf had to contact the inventors directly, so would have been able to filter out obvious cases of abuse.