During job interviews, it's illegal to ask the interviewee about his/her personal life. Because of this hiring decisions are based of information and statistics. Years ago, when a women worked and got pregnant, she still got paid while being pregnant even though she didn't work. At the same time, she didn't need to go back to the same job, she could quit just after giving birth and earned about 5 months in wages for doing nothing. Because of this, people hired more men than women. They couldn't ask the women if she was planning to have a family. The ones that didn't received unfair treatment, but there's nothing that they can do. This is called rational discrimination.
Sometimes, there are ways to avoid it, but not completely. The law for pregnant women changed, and for them to get paid while being pregnant and not working they had to continue working for a certain amount of time after giving birth.
Another clear example is skin color. You certainly don't want people in your company with criminal background. 28% of black males have served in prison before, while only 4% of of white male applicants have. Because of this, even though its unfair for that 72% of black males, it is reasonable from the companies point of view to choose somebody with less chance of being involved in criminal action.
Another example of economics of information if the wage students earn after graduating from different colleges. A study shows that graduates from Ivy Leagues earn much more than graduates from other -not so prestigious- universities. Although there is one exception. Those students, who got accepted into both, a normal college and into an Ivy League school, and choose to go to the normal school, end up earning the same wage as the others, having had a less expensive education. This proofs that it is ultimately on you and how smart you are. Your knowledge and what you do with that knowledge.
Even though statistics are the best way to guide us in many cases, it's always asymmetric information we have access to. Some decisions might be logical to take, but nothing is 100% fair or guaranteed. That's why Economics, unlike any other science such as physics, is an unpredictable, dismal science.