The ban on grade-sharing has been enormously popular with students since it was adopted in 1998. Supporters say that it discouraged (or at least kept to a reasonable level) the kind of cut-throat competition for which business schools are known. With the ban, students said they were more comfortable helping one another or taking difficult courses.
And over at Wharton:
The Wharton School as an institution does not have a ban or requirement on disclosing grades, but the student government adopted a policy in 1994 banning the release of grades.
Serhan Secmen, student body president at Wharton, said that students there are proud that the policy is not a “top down” rule like the one Harvard is ending, but is one that they have come up with themselves. He said that even though the student government has no way to enforce the rule, students abide by it.
He said that keeping grades from prospective employers encourages “teamwork and student collaboration.”
I suppose there is an interesting mix of issues at play. There are the obvious individual incentives provided by grades, with the possible perverse group incentives. Of course group projects and grading may ameliorate these to some degree, if you can overcome the free rider problem.
And then you have the importance of signaling. Taking the grade signal out of the employer/student matching equation helps some and hurts others. I imagine this policy is great for pretty, white, dumb people, but everyone else who isn't covered by one of those adjectives should rethink their position.