College applicants and job hunters are often told to scour their networks for someone who could make a quick call or send an email on their behalf, telling the decision-maker a special applicant is heading their way.

But not much is known about whether and why these personal endorsements work. Do they get the applicant in the door? And once at the college or company, does the applicant benefit the organization they’ve tried so hard to join?

A Cornell researcher and his colleague offer the first empirical evidence answering these questions.

Personal endorsements do, in fact, give applicants a leg up on the competition, both in getting interviewed and admitted, according to their study of applicants to a university MBA program. Further, relative to their non-endorsed counterparts, endorsed individuals tend to go on to support the university at higher rates by taking on leadership roles as students and giving more generous monetary donations as alumni. However, colleges and companies may be missing out on valuable talent if they accept only endorsed applicants, the researchers note in “Best in Class: The Returns on Application Endorsements in Higher Education,” published in Administrative Science Quarterly.

“This research highlights how an endorser can have a large effect on who gets interviewed, and who gets admitted, into an MBA program,” said co-author Ben A. Rissing, assistant professor of organizational behavior in the ILR School.

Personal endorsements have been largely invisible to scholars, because they’re informal and therefore tough to track. Not much is known about the magnitude of their effects on selection or why decision-makers may favor endorsed applicants.

Rissing and his co-author, Emilio J. Castilla of the Massachusetts Institute of Technology, found an ideal research setting to explore this topic: an MBA program that tracked when applicants received personal endorsements from faculty members, business leaders, alumni, students, university staff and famous individuals.

Rissing and Castilla analyzed all 21,324 applicants (of which 4.8 percent were endorsed) seeking admission to a full-time MBA program during a seven-year period. “We compared how endorsed applicants fared in relation to non-endorsed applicants,” said Rissing, who studies hiring and selection decisions in organizations.

Endorsed applicants were interviewed about 82 percent of the time, while those without endorsements scored an interview only 34 percent of the time. Among those who interviewed, endorsed applicants received offers to join the program 64 percent of the time, while those without endorsements got offers only 52 percent of the time. “These are big differences,” Rissing said.

The researchers examined two possible explanations. On one hand, endorsements may convey information about candidates, allowing decision-makers to identify better-qualified applicants or individuals that may go on to be better performers. On the other hand, endorsements may help decision-makers identify applicants who may be more likely to support the organization after joining it.

The researchers analyzed information on the applicant pool and the students who ultimately attended the school, including data on their grades, leadership positions in student clubs, salary after graduation and monetary donations to the university as alumni.

They found that endorsed individuals were no more qualified than their non-endorsed counterparts, based on merit-based competency assessments conducted by admissions staff who didn’t know the applicants’ endorsement status. While endorsed applicants were sometimes seen as stronger ‘‘on paper’’ (after a review of their application materials), they generally scored worse during interviews than non-endorsed applicants. Further, students who were endorsed as applicants were neither better performers academically (in terms of awards or GPA) or on the job market after graduation (in terms of salary or signing bonuses).

That said, those who were endorsed as applicants did emerge as ‘‘better citizens” (more likely to lead student clubs) and ‘‘better alumni” (more likely to donate to the university, and notably, more likely to give large amounts) than those who had not been endorsed.

Endorsements do seem to identify individuals who will be committed to the organization. But they do not necessarily identify better-qualified candidates, Rissing said. “Organizations should go through their application process and ask, ‘Are we selecting on applicant characteristics that are going to result in organizational members who are most desirable?’” he said. In selecting for qualified applicants and those who are community-minded, he said, “It’s a question of how to balance the two of these considerations, so one doesn’t overwhelm the other. Both have merits.”

The study also raises concerns about inequality. For example, first-generation students, immigrants, and students without financial resources might not yet have contacts who are willing or able endorse them, Rissing said. “There are smart, qualified and community-minded individuals in all of these groups. Is their potential lack of awareness of these endorsement channels going to limit their opportunities?” he said. “Decision-makers must be attentive to the reality that access to these types of social connections, such as endorsements, are not ubiquitous.”