In theory, if you are an employee and you discriminated against because of your age by your employer, you have the right bring in the Feds down on your employer. It is something that a young employee, say 30 years old, cannot do.

Now, say you are looking at two potential employees, one 30 and one 50 of apparently comparable relevant skills. Who's got the edge? Do you want to risk potential legal problems with the older prospect? Choices can always be justified for intangible reasons.