Unlike most economists, I subscribe to People Magazine. Fame interests me. Several of my papers (joint with Dora Costa) are about non-market social interactions. Someone is famous if many people agree that this person is an "important" person but what does the word "important" mean? It is possible that every person in the U.S could have a different ranking of who is "important" and who isn't. In this "horizontal" case, everyone one be "famous" and "nobody" would be famous. In the real world, people's rankings of who is "important" are highly positively correlated. Many people seem to genuinely care about what Paris Hilton is up to. Do you care? Why do you care?
I don't know the answer to that deep question but I wanted to offer a few celebrity sitings near UCLA. I missed Britney Spears recently partying at the nearby W Hotel.
But, just now I can verify a Rick Fox siting. Do you remember this solid NBA player who was married to a Miss Universe? (see http://www.nba.com/playerfile/rick_fox/)
I was just at a nice restaurant in Westwood watching the Patriots/Chargers game at the bar when Rick Fox and another dude sat next to me at the bar. He was wearing a Tom Brady jersey and wasn't happy that Brady wasn't playing well. We chatted about why Payton Manning is having a bad playoffs.
I can't say that during my years in Cambridge that I spotted many celebrities. If you count Steven Jay Gould and his type then maybe yes but that gets into what is your definition of fame!