> The greatest source of admissions inequity is childhood socioeconomic status

If we are talking about the US, no, I disagree.

The greatest source of admissions inequity are shit K-12 education.

I'll give you a direct example from when my kids were at the local middle school. Their science teacher --a Chiropractor-turned-teacher-- was, well, there's no other way to put it, a moron. The guy actually taught the kids that the moon does not spin...at all. They, quite literally, had to answer the question that way on a test in order to get the points. I can't even remember the number of horrifically wrong things this guy was teaching his students. By the time my kids got to his class he had been there for about twenty years.

It didn't end there. This guy was a bad teacher. He was angry, had self-confidence problems, would yell and scream at the kids, etc. If a kid had a question he would sometimes tell them "That's stupid question" in front of the entire class. Just horrible.

I lost count of how many times I met with the school principal and vice principal to file complaints. I had many (friendly) conversations with him. He was clearly intimidated by someone who's daily life was about science and engineering. I offered to come in once a week to help out and bring stuff with me to inspire the kids (robots, space-related stuff I was working on, etc.). Heck, I offered to arrange for the kids to take a tour of a rocket-making factory. He never took me up on the offer.

My kids, to this day, tell me their science education happened at home because that guy was a clown and other teachers were ineffective. There was no way to get this guy fired. He did not belong in a school, at all. He is still there. That school might get a better science teacher once he retires...with full benefits for life.

I have other examples of truly bad teachers doing the kids a horrible disservice. Unions protect them. You can't get rid of them. We somehow accept this and it permeates the land.

The bottom line is that we, the inhabitants of this land, pay taxes and fund schools that are going a horrible job of educating our children. The school is where we can clearly make an effort to provide kids from all walks of life with better outcomes, regardless of socioeconomic status. They can be learning calculus and science even if their parents didn't finish high school and are not in a position to help or advise them. They can be using computers even if they can't afford them at home. They can take inspiring field trips to the most amazing universities, museums and companies even if they don't have the means to do that outside of school.

And yet, we don't do that. We don't have a unified nation-wide standard of excellence based on an absolute dedication to giving kids the best opportunities to learn, regardless of socioeconomics. Instead we hire people like the moron from my story, who, for thirty years, will not only teach nonsense to class-after-class, he also manages to destroy any potential opportunity for kids to get excited about learning science by being an absolute asshole.

Put a different way: If we had really good K-12 schools and results, university admissions would not be a problem for anyone at all and success rates would be amazing.