Spring is here, which means it’s time for elite colleges to send out acceptance letters. Some will go to athletes, the children of influential alumni and those who round out the school’s diversity profile. But most will go to the offspring of the upper middle class. We all know why, right? Affluent parents get their kids into the best colleges by sending them to private schools or spending lots of money on test preparation courses. Either way, it perpetuates privilege from generation to generation.

The College Board provides...