Well, you still didn't refute his position that this is not based on empirical data, just a few of your limited data points and personal bias (which is neither

Well, you still didn't refute his position that this is not based on empirical data, just a few of your limited data points and personal bias (which is neither good or bad; just something we all have). >> , I'd rather have someone with 30 years of work experience at four or more companies than someone with 30 years of experience at one company. Experience means depth and/or breadth, so what you're really saying is "I want someone with 30 years experience, not 30x 1 year of experience. Multiple companies increases the odds that they'll at least have breadth". This is a valid strategy but still a bias. There was a time when many people worked at the same company for their entire career as the desired path, not some form of settling or indicator of limited skills. It's only a generation or two that has not experienced this.