Controlling for SAT/ACT score should not be taken lightly. The same author lists the following distribution of SAT scores by income level. Controlling for SAT effectively means you expect the Ivy+ distribution to be similar to the ratio below with 99th percentile income kids being ~100x more likely to attend than low income kids. If low income kids are 50x less likely to enroll, rather than 100x, then the low income kids are overrepresented after controlling for score.
Portion of Kids Scoring 1400+ on SAT by Parents Income
99.9 Percentile Income – 19%
99th Percentile Income – 14%
98th Percentile Income – 11%
97th Percentile Income – 10%
96th Percentile Income – 8%
95th Percentile Income – 7%
90-95th Percentile – 5%
80-90th Percentile – 3%
70-80th Percentile – 2%
60-70th Percentile – 1%
50-60th Percentile – 0.7%
40-50th Percentile – 0.4%
20-40th Percentile – 0.3%
0-20th Percentile – 0.1%
The author lists the actual distribution by income level at the median parents income Ivy+ college. Over/under represented is a comparison to income distribution in US population. The pattern is the higher the income level, the more likely the student is to attend an Ivy+ college.
3.1% of students in 99.9th percentile income (31x overrepresented)
17% of students in 99th percentile income (17x overrepresented)
27% of students in 95-98th percentile income (7x overrepresented)
14% of students in 90-94th percentile income (3x overrepresented, median income)
14% of students in 80-89th percentile income (roughly balanced)
12% of students in 60-79th percentile income (2x underrepresented)
14% of students in 20-59th percentile income (3x underrepresented)
2% of students in 0-19th percentile income (10x underrepresented)