And the laws are kind of weird. If you say you discriminate, but don't, you've committed a crime. If you say you don't discriminate, but do, it's not a crime. (I think the reality is that everyone discriminates in favor of "people they like" anyway. It is somewhat scary that we have so many thought crimes now.)
The paper is "Implicit Discrimination." Marianne Bertrand, Dolly Chugh and Sendhil Mullainathan; American Economic Review, 2005, 95(2), pp. 94-98.
if you have access. Unfortunately, I don't at this time.
The basic results are that a resume with a 'black' name versus a 'white' name (and no other difference) are far less likely to fetch callbacks. Further, there's no appreciable difference in callbacks for black candidates with increasing skills, whereas there's a drastic increase for white candidates.
There are many other studies, and then there's my own, personal experience, which I'm not about to get into.
I presume you're referring to age/gender discrimination.
At least people generally recognize that sexism is wrong. There is a lot less raised consciousness when it comes to ageism.
You start college early, and everyone says you're too young. And then later, ironically, you find when you hit 30 that the thinking has recently shifted when it comes to start-ups, so then you're too old.