It’s always been assumed that one company’s loss is another’s gain when an employee jumps ship. Just think of the knowledge, experience and connections that go out the door along with a person’s boxes and office belongings. But now a new study suggests that losing an employee, at least in a high-tech field, is not necessarily as bad as it seems. “Firms can wind up learning when employees leave their firm, which is contrary to the conventional wisdom — that firms learn by hiring away employees,” says Wharton management professor Lori Rosenkopf . She and Wharton doctoral student Rafael A. Corredoira present their conclusions in a paper titled, “Learning from Those Who Left: The Reverse Transfer of Knowledge through Mobility Ties.” The two researchers came up with their silver-lining finding by studying the effects of “outbound mobility” on semiconductor firms in the United States and abroad.…