as far as society is concerned, professional athletes do have value - that value is realized in the form of ticket prices, memorabilia, endorsements, etc. And you can measure that in dollars, obviously. Keep in mind, these are professionals. There's only like 700-800 of them per professional league, and their athletic careers span 0-20 years. You could similarly do that calculation for hollywood too. That's the supply side. The demand side: it provides joy; it's entertaining, it's emotional, and fun. People pay for that, for the most part. Of course some people don't feel it;s worth paying for. that's fine too. But there's enough of the payers to sustain industries.