The study (which strangely isn't available on SSRN or the author's website) appears to be about recruiting law and b-school grads.
I wouldn't be that surprised if her results are true. Whenever there are lots of applicants and lots of employer uncertainty about applicant quality, screening on things like credentials that correlate (however weakly) with average ability can still be "rational."
To give an example, assume that GMAT score is a) unobservable by employers and b) perfectly predictive of future performance in the firm. If HBS grads have a mean 1 point advantage over Sloan grads, it makes sense to lexically prefer HBS to Sloan grads, even though slightly less than half the time the employer will make the wrong (ex post) hiring choice.
This dynamic also tends to be self-reinforcing. If credentials are all that matter to future employers (and all schools cost the same), then all students will try to attend the most prestigious school they can. If admissions committees are not pure coin flips, then it makes sense for employers to believe that the HBS/Sloan "distinction" means something.
I wouldn't be that surprised if her results are true. Whenever there are lots of applicants and lots of employer uncertainty about applicant quality, screening on things like credentials that correlate (however weakly) with average ability can still be "rational."
To give an example, assume that GMAT score is a) unobservable by employers and b) perfectly predictive of future performance in the firm. If HBS grads have a mean 1 point advantage over Sloan grads, it makes sense to lexically prefer HBS to Sloan grads, even though slightly less than half the time the employer will make the wrong (ex post) hiring choice.
This dynamic also tends to be self-reinforcing. If credentials are all that matter to future employers (and all schools cost the same), then all students will try to attend the most prestigious school they can. If admissions committees are not pure coin flips, then it makes sense for employers to believe that the HBS/Sloan "distinction" means something.