Random selection is necessary to create stable meritocratic institutions

I’ve long thought college admissions should be done randomly from a pool of eligible candidates.

There is just no evidence that like 50 point differences in admissions tests are predictive of anything.

I think the issue is that the (American) standardized tests don't differentiate well enough. About 10,000 American high school graduates earn a 36 on the ACT or 1580+ on the SAT each year. That's because the problems are much too easy—the very first round of MATHCOUNTS, a middle school math competition, is harder than the ACT or SAT math section. Rather than making the test harder, they make it trickier. It's like that exercise lots of us did in elementary school to learn to follow instructions, where they ask you to read through all the instructions first, ask you to do a bunch of random things, and then hidden in there somewhere is "ignore all the previous instructions and just write your name at the top of the paper". The test isn't hard, but you'll be prone to mess up if you haven't seen that style of testing before (for the SAT, it's 90sec/problem with problems that try to break your pattern recognition, e.g. what is 1 + 2 + 3 + 4 + 5 + 7 + 8 + 9 + 10?).

An 800 on the math section is not enough to even predict if someone made it to the AIME, but it is enough to predict that they spent several weeks taking SAT math section practice tests. It's clearly failing to be predicative of anything the top universities should be looking for. It doesn't mean all standardized tests have to be. The AMC (and then the AIME + USAMO) are standardized tests that universities like MIT do accept scores from, and they actually get useful information from.

But why should it be harder? Why should the goal be to produce a fine gradation of ability?

Why not just evaluate a cut-off for “very likely to do well” and then make it random?

It’s not like the narrow set of skills measured by the test are all there is to doing well at university. They are never going to be fully predictive.

Because it feels bad to know you didn't make the cut because you were unlucky since there's nothing you could have done better.

Sufficient preparation can mitigate low scores, they can't mitigate bad luck.

:s/preparation/wealth/g

I see that, but does it not feel equally bad to know you did not make the cut, despite being just as likely to succeed, because of wealth, race, religion, connections etc?