This article is not about foreign students in US colleges, but I thought I would add it to this thread because it's a well written article by Devin Pope about how colleges can admit higher-quality students.

Nearly all colleges, for example, make use of two metrics to gauge student quality: cumulative high school grade point average and composite score on the ACT (the most widely taken college admissions exam). But research has shown that these metrics are imperfect: They are less predictive of student success than alternative measures that are equally simple to calculate and whose use would lead to a better incoming class.


Consider grade point average. Students whose overall G.P.A. is a result of doing better later in high school (say, junior and senior years) are much more likely to succeed in college than students with the same overall G.P.A. who did better early in high school (say, freshman and sophomore years).


By using the ACT composite score, college admissions offices are giving equal weight to each of the four subtests. But in a 2013 paper I wrote with the education researchers Eric Bettinger and Brent Evans, using data from public college students in Ohio, we provide evidence that the math and English subject tests are far more predictive of college success than the reading and science tests.