How much advantage do the children of alumni have in admissions? How much should they have?

This question periodically surfaces in higher education, and has done so again in recent weeks with news that the U.S. Justice Department is investigating possible illegal discrimination in admissions programs at elite colleges. If colleges might be told not to consider race and ethnicity, many critics say, why is it OK for them to consider alumni status -- a factor that these days overwhelmingly benefits white applicants, many of them wealthy.

Various studies over the years have compared the admission rates of legacies versus other applicants. In his 2006 book The Price of Admission, Daniel Golden was sharply critical of the practice of preferences for legacy applicants. "At Ivy League and other elite schools, alumni sons and daughters typically make up 10 to 15 percent of the student body, despite lesser academic credentials," he wrote. "Legacies are two to four times more likely to be accepted than other applicants, and many elite universities enroll more legacies than either African-American or Hispanic students."

Defenders of legacy preferences generally push back on the Golden argument about "lesser academic credentials." In the United States, they say, children of college-educated parents have higher educational attainment than others. And this is true for the wealthy as well. So it's not surprising that alumni children do well in admissions, defenders of legacy admissions argue.

But are there truly national data? In 2003, the late Senator Edward M. Kennedy (a Harvard University graduate who was the son of a Harvard graduate) introduced a bill that would have required colleges to publish their admit rates for legacy and nonlegacy candidates, and information on the socioeconomic backgrounds of legacy admits. The bill went nowhere.

Data from Naviance, a tool from Hobsons now used in high schools that educate 40 percent of high school students, may offer insights on a national level. One part of Naviance tracks the success of students in getting into various colleges, so that high school students and counselors can see the odds of students with certain grades, test scores and interests of gaining admission to certain colleges.

Hobsons shared some data on legacy admissions from its national pool -- and the data may encourage both critics and defenders of legacy admissions. Spoiler alert: there's no smoking gun.

The Naviance database had data on 15,402 legacy applications from the high school classes of 2014-17 in its database, considering only the 64 colleges with 100 or more legacy applicants each during that time period, so that small numbers of legacy applicants would not skew results.

The results show that reports of much higher admit rates for legacies are accurate. The average acceptance rate across these institutions was 31 percentage points higher for legacy applicants than the colleges' published acceptance rate for all students. The acceptance rate for legacy applicants was above average for 52 institutions and lower than average at 12 institutions.

Hobsons officials stressed that this was not based on a multivariable analysis. So the higher admit rates for legacies could be due to factors beyond alumni child status.

Indeed, another part of the data from Naviance suggests that most (but not all) legacy applicants are qualified for admission academically.

Naviance has various measures to see if applicants are academically "matched" or not. Comparing ACT or SAT scores to the middle 50th percentile of test scores for each of the colleges, the data show that 48 percent of legacy applications are in that range. Further, 34 percent are above that range, perhaps backing up comments from some guidance counselors about parents pressuring children to enroll at their alma mater -- even in cases where a son or daughter could earn admission to an institution with stronger academics.

Of course that also means that 18 percent of the legacy applicants are below the range.

Amy Reitz, general manager of Intersect, a division of Hobsons, said the data raise interesting ideas but do not demonstrate the kind of bias many assume exists -- at least on a national level.

"There may be an underlying correlation regarding parent education and how that manifests itself in student performance," she said via email. "But by and large, the data appears to be indicating that admission of legacy applicants based on qualifications is in line with nonlegacy applicants. If anything, we’re seeing overrepresentation of overqualified applicants -- meaning legacy applicants are more likely to be academically overqualified for the same institution their parent(s) attended than the general population."