To give some perspective, if you search at Google News, there are 14,900 press pages currently mentioning "Cohen" (e.g., Sacha Baron-Cohen) and 14,500 currently mentioning "Wang" (e.g., Vera Wang), or about 1 to 1, not 49 to 1.
According to Wikipedia, the most common surnames in the U.S. in 2000 were, among white-black names, Adams (3 semifinalists in California), Johnson (3), Williams (3), Brown (6), Jones (7), Miller (2), Davis (1), Wilson (2), Anderson (3), Taylor (3), Thomas (1), However, this Wikipedia list of top 100 surnames is, for unexplained reasons, missing Smith (7).
Among celebrity names, I see a Munger in Palo Alto -- likely a relative of billionaire Charlie Munger, Warren Buffett's gray eminence.
In California, high schools with the most semifinalists include Troy in Fullerton (80), University High in Irvine (60), Lynbrook in San Jose (58), Mission San Jose in Fremont (55), Monte Vista in Cupertino (53), Harker School in San Jose (50), Torrey Pines in north San Diego (48), Harvard-Westlake in North Hollywood (42), Palo Alto (46), Henry M. Gunn in Palo Alto (42), Palos Verdes Penninsula (36), and Arcadia (31). Most of these are public schools, with the exception of Harker and Harvard-Westlake.
Basically, having a lot of semifinalists is now all about having the East Asians. For example, among famous LA schools, Beverly Hills H.S. has eight, Loyola of Los Angeles six, Marlborough of Los Angeles four, Milken of Stephen Wise Temple ten, and Windward in Santa Monica (zero). Those are excellent numbers (except for Windward, which is where movie stars traditionally sent their, uh, more artistic scions), but these five prominent schools add up to 25% of Troy H.S. in Fullerton. Fullerton?
The semifinalists at Harvard-Westlake on Coldwater Canyon are a little less than half East Asian, but, still ... the school's two campuses (the other is just off Sunset Boulevard) are at the historic center of what had been the largest, richest Jewish community in the world outside of NYC
It would be interesting to calculate a sort of GINI score of inequality by high school for semifinalists. Some of these public schools have more semifinalists per year than most public schools in California could be expected to have in a century at recent rates.
For example, in contrast to Troy H.S. with 80, the city of Los Angeles (not counting the San Fernando Valley) has a total of five public school semifinalists: two at LA H.S. for the Performing Arts, one at LACES (the top academic magnet public high school in LAUSD), and one each at Venice HS (at the beach) and one at Eagle Rock HS (next to Pasadena).I'd roughly estimate there are about 50,000 sixteen year olds within these boundaries (although lots are in private schools or have dropped out), so, 5 out of 50,000 ...
The San Fernando Valley is more reasonable with about 30 semifinalists in LA public schools (although it lags well behind the public schools of the more Asian San Gabriel Valley), but the inequality of the main LA Basin is remarkable.
Another interesting thing is to compare San Francisco to San Jose -- maybe four or five times more semifinalists in San Jose than in San Francisco.