Who Gets Into Ivy League Colleges?

We use anonymized admissions data from several colleges linked to income tax records and SAT and ACT test scores to study the determinants and causal effects of attending Ivy-Plus colleges (Ivy League, Stanford, MIT, Duke, and Chicago). 

Children from families in the top 1% are more than twice as likely to attend an Ivy-Plus college as those from middle-class families with comparable SAT/ACT scores. Two-thirds of this gap is due to higher admissions rates for students with comparable test scores from high-income families; the remaining third is due to differences in rates of application and matriculation. 

In contrast, children from high-income families have no admissions advantage at flagship public colleges. The high-income admissions advantage at Ivy-Plus colleges is driven by three factors: (1) preferences for children of alumni, (2) weight placed on non-academic credentials, and (3) athletic recruitment. 

Using a new research design that isolates idiosyncratic variation in admissions decisions for waitlisted applicants, we show that attending an Ivy-Plus college instead of the average flagship public college increases students’ chances of reaching the top 1% of the earnings distribution by 50%, nearly doubles their chances of attending an elite graduate school, and almost triples their chances of working at a prestigious firm. 

The three factors that give children from high-income families an admissions advantage are uncorrelated or negatively correlated with post-college outcomes, whereas academic credentials such as SAT/ACT scores are highly predictive of post-college success.

That is from a new paper by Raj Chetty, David J. Deming, and John N. Friedman. One immediate conclusion is that standardized test scores help lower-income groups get into the best schools, compared to the alternatives.

From Tyler Cohen at Marginal Revolution. 

It is well known and consistent with experience that graduating from an Ivy-Plus college is a huge advantage over graduating from a flagship public university.

The fact that Ivy-Plus colleges favor legacies is well known. The fact that admissions favoritism for athletes disproportionately favors students from affluent families (often in obscure sports that students from less affluent families don't even encounter) is much less widely known. It is unsurprising, however, that neither of these factors (controlling for academics and Ivy-Plus admission) influence post-graduation outcomes much (or even hurt). 

It is also no surprise that non-academic credential are important for Ivy-Plus admission or that affluence is a plus in this department. But it is somewhat surprising that those non-academic credentials don't influence post-graduation outcomes much (or even hurt).

A few points that the abstract buries, however, are that SAT/ACT scores are moderately strongly correlated with socio-economic class, that SAT/ACT scores are strongly correlated with IQ (and are not ethnically biased), and that test preparation influences SAT/ACT score outcomes much less than most people (even people very familiar with the college application process) usually believe. See also here. As an aside:

ACT English + ACT Math are actually more predictive of college success and retention than the ACT Composite or the other two parts of the ACT that are more content based. In relative terms, here is how predictive each subsection of the ACT is:

Math (significant at p=0.01 level) 26

English (significant at p=0.01 level) 16

Reading (significant at p=0.05 level) 3

Science (not statistically significant) -1.

Race and ethnicity also influence Ivy-Plus admissions, although in ways rather more complicated than commonly assumed, and in a manner that is rapidly in flux at the moment in light of a recent U.S. Supreme Court decision.

None of this is terribly surprising, but it is a nice, compact analysis with a good methodology. It largely corroborates a similar study about two years ago. As a summary of that study explained:

About 7 percent of the country’s very top students come from the top 1 percent of the income distribution. These students tend to have scored at least 1500 on the SAT (or 35 on the ACT), received top marks on Advanced Placement tests, earned almost all A’s in their high school classes, and often excelled in science fairs or other competitions. . . . 

Perhaps the most surprising pattern involves so-called legacy students, those who attend the same college that their parents did. At the elite colleges that the researchers studied, legacy students had stronger academic qualifications on average than nonlegacy students. Similarly, graduates of private high schools had stronger academic records on average than graduates of public high schools or Catholic schools. 

* . . . About half of legacy students at these colleges would not be there without the admissions boost they receive.  

* A similar advantage applies to the graduates of private schools (not including religious schools). Schools like Andover, Brentwood and Dalton do such a good job of selling their students — through teacher recommendations, essay editing and other help — that colleges admit them more often than academic merit would dictate. Many college admissions officers think they can see through this polish, but they don’t.  

* Recruited athletes are admitted with much lower academic standards — and are disproportionately affluent. It’s not just true of the obvious teams, like golf, squash, fencing and sailing. In today’s era of expensive youth sports, most teams skew wealthy. If colleges changed their approach to sports, they could admit more middle-class and poor athletes (or nonathletes) with stronger academic credentials.

Most of these colleges do not admit only the hyper-qualified affluent students; they also admit many other high-income students. As I mentioned above, 7 percent of the country’s very best high school students come from the top 1 percent of the income distribution. But what proportion of students at elite colleges comes from the top 1 percent of the income distribution? Much more: 16 percent.

I didn't emphasize it when I wrote about this two years ago, but it also is worth observing that 84% of Ivy-Plus college students are not from families in the top 1 percent of the income distribution, although very few of them are truly poor (and if they are poor, they tend to have a very high socio-economic class and social capital despite their personal lack of affluence). This is less than the 93% it would be in a purely meritocratic system, but it is still the lion's share of these students.

Indeed, the colleges with the most affluent student bodies are not the Ivy-Plus schools, but slightly less selective elite liberal arts colleges, like Colby College in Maine and Colorado College in Colorado, that have relatively weak grant based financial aid resources.