I recently caught up with Bob Josephs at this year's SPIT (Social Psychologists in Texas) conference in Austin. Bob was in the same graduate-student cohort with me at Michigan, although in an unconventional way.
As I and my fellow incoming students were starting out at Michigan in the Fall 1984 semester, Bob was beginning grad school at the University of Washington. However, when Bob's advisor, Claude Steele, moved from U-Dub to Michigan in the Fall 1987 semester, Bob came along. In terms of graduate-school experience, Bob was the equivalent of the Fall '84 entering cohort, so he was grouped with us.
Upon completing his Ph.D. at UM, Bob joined the faculty at the University of Texas-Austin for the Fall 1990 term, and he's been there ever since. As I discussed with Bob during SPIT, it seems relatively rare for someone to have had one -- and only one -- position since completing grad school. For one thing, it requires someone to land a tenure-track job immediately, without the need for a post-doc or visiting position. Then, one has to like one's department and university, and the department and university have to like you (i.e., grant you tenure).
Bob is by no means the only graduate of the Michigan Ph.D. program to stay exclusively in one place, but it seemed easier for us to generate names of people who've moved at least once than names of people who've stayed put.