Fibula, when my husband was in vet school I worked at a large university, Auburn, as a "part-time adjunct instructor" (official title) in the chemistry department. I assisted a professor who had ~700 students by proofreading the text he was writing, supervising exam preparation and grading, conducting help sessions, and on rare occasions delivering lectures. I was essentially the liason between the professor and students. I only had a BS degree (that's the degree given to a college student after four years of college work). Most US colleges give a BS (Bachelor of Sciences) and a BA (Bachelor of Arts). In chemistry, the BS is the tougher degree in most schools, (there are a few exceptions.) All this to say, Auburn, and I assume most schools, are concerned about accreditation, so they don't want teachers on staff that don't have higher degrees such as PhD. Therefore, they use instructors with lesser degrees, but just give them other names. I think they used people in the health professions, ie dentists, in a similar way.
And mcmoo, industry also rewards one according to the degree as opposed to the achievement. I worked in one lab as a technician (and was paid as a technician) and did more advanced work (chemical patent) than at another company where I was an official "chemist."
Back to the original question...Peter said it all, as usual.