Shamus Khan ( Sociology Professor at Columbia University ) says :

I am a college professor. And as I look at such data, I cannot help but think that I am part of a great credentialing mill. Colleges are increasingly places for the rich. It’s too simplistic, but this is pretty much the story. Colleges admit already advantaged Americans. They don’t ask them to do much or learn much. At the end of four years, we give them a certificate. That certificate entitles them to higher earnings. Schools help obscure the aristocratic quality to American life. They do so by converting birthrights (which we all think are unfair) into credentials (which have the appearance of merit).