"The Dead in the Classroom," by Stephen Rushen.

To an early morning freshman economics class of thirty live students, fifteen dead students were added.  Performance of both live and dead students was observed through the course of the semester.  Data are presented in the categories of:  attendance; behavior; participation; and exam scores.  In three of the four areas, the dead students' performance was the equal of, if not superior to, that of their living peers.