Last week I posed a question: what five cities are home to the greatest number of my Harvard classmates?

Without a doubt, this was the hardest quiz ever on this blog. Over 1,000 guesses were made; the first 851 of these guesses were wrong. (Actually, blog reader Len sort of had the right answer earlier, but it is totally obvious if you’ve ever seen the red book that is my data source, that he cheated.)

Not until John F. came along with comment number 821 did someone end the misery by getting all five cities correct (with number of my classmates in parentheses):

• New York (approx. 250)
• San Francisco (55)
• Los Angeles (38)
• Cambridge (35)
• Washington, DC (31)

Other cities that were close to the top five were Seattle with 22 and London with 21.

What made this question so hard? My crack researchers Jordan Ou and Laura Rivera analyzed the guesses made by the first 250 guessers. Here is how often various cities were named

• New York (233)
• Boston (178)
• Washington, DC (153)
• Chicago (126)
• Los Angeles (104)
• San Francisco (93)
• London (87)
• Houston (24)
• Seattle (20)
• Cambridge (17)
• Shanghai (15)
• Hong Kong (13)

So what really hurt people was including Boston and Chicago which, surprisingly, are home to only 20 and 18 of my classmates respectively. Hardly anyone guessed that so many of my classmates would stay right in Cambridge.

I was surprised how few Harvard alums live in Chicago. Amazingly, there are almost as many of my classmates in Oakland (14) as there are in Chicago, and yet not a single person in the first 250 guessed Oakland.

Another thing that is surprising, given the answers people gave, is how long it took to get a correct answer. Imagine you had an urn filled with balls that each had one city’s name on it, with the balls in proportion to the frequency with which blog readers named each city (e.g. 233 New York balls,
178 Boston balls, etc.). Now randomly pull balls out of that urn until you get five unique cities. The probability that the five balls that you end up with will match the correct five cities, by my calculations, is about 1 in 166. So the fact that it took over 800 guesses to get the right answer suggests that there was a negative correlation between some of the winning cities. So, for instance, guessers who thought people didn’t move far tended to list both Cambridge and Boston, but rarely mentioned Los Angeles or San Francisco.

And to all of you who guessed foreign cities, the simple fact is that hardly any of my classmates live abroad, except for those who were foreigners to begin with (most of the Canadians went back home) or moved to London. Eight of my classmates are in France and Hong Kong, but just three live in mainland China. The most unlikely place I could find one of my classmates living: Albania.

#### Michael C

New York was pretty much a given, and Cambridge was clearly the hardest one to get.

I think what made the question so hard was that most people who are unfamiliar with Massachusetts had trouble thinking of Cambridge as a distinct city from Boston.

#### Harold

I think most people were considering Cambridge and Boston to be equivalent.

#### David

Shouldn't Cambridge and Boston be lumped together? Those of us who haven't been to Boston probably aren't aware there's a difference; i.e., that Cambridge isn't just a neighborhood or a suburb. If you asked me where Harvard is, I'd say Boston.

This is relevant because my guess it that a sizable number of people listed under "New York City" don't actually live _in_ New York City.

#### Will C

I've been wondering when we'd get the answer, trying to be patient!

I wonder how much the delay to get the right answer was due to the mistake I made: I considered Cambridge to be part of Boston. It's part of the Boston area as a suburb after all.

#### MattWalker

I think most people were counting Cambridge and Boston as the same city.

#### K

Having "Cambridge" in the list with the other large cities is a bit of a problem. You have four metro areas and one standalone city. Lots of people will say they are from Boston, but they really mean "metro Boston", because no one knows where "Newton" or "Waltham" are. People might know where "Cambridge" is, but I'm guessing that many Cantabridgians simply say they live in Boston when somewhere else in the country. Otherwise, the conversation goes like this:

Cantabridgian: "I live in Cambridge"
Unwashed heathen: "Where?"
Cantabridgian: "The Boston area"

#### T-Bill

To those of us not enamored of Harvard (okay, I am a Yalie), a Boston guess should encompass Cambridge for purposes of this query. To give Cambridge distinct status is sort of like parsing the Des Moines suburb of West Des Moines. But then, I would consider Oakland to be San Francisco. If two town are served by the same commuter system, that is a good sign they are part of the same metro area (and who really knows where someone lives as distinct from works in a metro area over time).

#### Justin Harper

How do you know that Len cheated?

#### Al

You mean no Harvard people live in Yuba City, CA; or Cranston, RI; or Laredo, TX?

What's goin' on, are they just snobs?

Al

#### SPM

I'll admit to having no idea where people may have lived. However, I did the same thing you pointed at where I examined the first 50 or so answers, found the most popular and then tried to assemble a list that hadn't been posted yet.

I'm curious how many people did the same thing I did? Looks as if we were self defeating by encouraging people to vote for popular incorrect cities.

#### Eric

My correct guess had boston and cambridge lumped together like most others. All the other locations listed are metro areas. The correct test is what is the answer that someone would give if asked where they live (when lot currently located near their home). Anyone living in Cambridge would answer "Boston".

#### KB

I agree that this would be more useful by MSA.

The big pattern might be that so many people end up on the coast. I'd also wonder how this compares with where classmates came from to begin with.

#### Andy O.

I agree with the other comments regarding lumping Cambridge and Boston together (makes it tied for location #2 with S.F.). Given this, guess #26 would have won.

Lumping Boston + Cambridge together seems to indicate that it took a mere 26 comments to get the correct answer: http://bit.ly/c3cpe

Congrats Megan!

#### Matthew

1 in 166, eh? Read #162. All the cities, mostly correct order.

Cambridge = Boston.

#### Kathy A.

I didn't guess, but count me among those who thought of Cambridge and Boston as being the same. So much so that when Cambridge was listed as an answer, my first thought was "Why did so many move to England and didn't go to London?"

#### GarryS

Did you mean to say that the "first 820 of these guesses were wrong"?

#### Dave

Why would it be so surprising that a classmate would live in Albania? It seems to rank higher than mainland China in terms of this "relative quality of life" index:

http://www.il-ireland.com/il/qofl2008/#Albania

#### Stephanie

I live in Cambridge and I say that I live in Cambridge. Cambridge and Boston are quite different; it's not just a river that separates us, but a way of life!

#### Yuval

...So now we're in for 851 comments of how people meant "Boston+Cambridge" when they said "Boston"?