Something I have always suspected happening in labor markets does, in fact, seem to be happening: hiring managers tend to give a premium to those signalling athletic ability or sport participation. The paper, by Dan Olof-Rooth, looking at these results is linked below:
I think this is extremely interesting (and mirrors the studies that randomized "African American sounding names" on resumes, finding bias there). Of course, there are different signals sent with athleticism vs. the sound of names. A name isn't likely to signal much, maybe skin color, which we all know is not a valid way to exclude someone from a job.
However, athleticism could signal something else: motivation and time management. My undergraduate thesis (unpublished) found that student athletes felt (self-reported) much better about their time management skills than non-athletes. This could be a useful signal for someone hiring a prospective employee.
Secondly, those who participate in sports tend to be more active and have more energy than those who do not. These would also seem to be desirable skills for an employer.
Lastly, being athletic could signal motivation or initiative from the person applying. This is similar to participating in a club or being president of the young business leaders organization at your university. I don't know that athletics would give an advantage above and beyond something like this, but it would seem to be at least a useful signal about involvement and social skills. Team sports are social, and can provide opportunity to grow just as other clubs do.
All of these things are difficult to observe in an interview, so using sport participation as an implicit signal can be useful both for the employee to relay this information, and for the employer to get a bit more information about the prospective hire. Of course, there is also the possibility of overt bias toward playing football or some other sport at a large university that the employer is a fan of. This would not be a valid way to make a hire, but I suspect it does happen. There is always a "buddy network" influencing many areas.
This is why I tend to always put on my CV or Resume that I participated in college athletics and currently continue to play softball and golf. While it says nothing about my skills as an academic researcher (leaving aside the fact that I research sport), I suspect that at worst it will do nothing for me and at best make the employer slightly more interested.
What say you?