Worldline demographics

I’ve often thought, looking around my neighborhood on Chicago’s North Side, that there must be some obscure city ordinance that force people to move out once they either hit the age of 40 or have kids. I found a way to quantify just how tightly bunched the local demographics of my neighborhood really are: City-Data.com gives you the raw data about the composition of anywhere in the U.S., and some fascinating graphical representations of who lives there.

So I studied my personal history as told through the demographics of the zip codes in which I lived (somewhat streamlined for dramatic purposes). You can’t really choose where you are born, and I grew up in the depths of the Philadelphia suburbs, in 19067. Here is a graph of the number of people in the zip code as a function of their age; black for males, magenta for females (hey, I don’t pick the color schemes).


You can tell instantly that it’s a middle-class child-raising family community; a bunch of kids, most of whom flee at the age of 18 to go to college, then gradually trickle back to buy homes and raise their own kids — if not the exact same people who grew up there, then their demographic equivalents. As they become slightly more prosperous or the kids move out and they don’t need a three-bedroom house with a yard, they decamp to more appropriate locales.

Next it was on to college at Villanova, in the scenic zip of 19085.


Clearly, nobody lives there but the college students. It must be that the zip code only includes the university proper, as the surrounding area was populated by the old-money upper class of Philadelphia’s Main Line.

Then to grad school at Harvard and the celebrated destination of 02138, where they used to sell T-shirts proudly proclaiming it as “The Most Opinionated Zip Code in America.”


Dominated by college students, but somewhat more inclusive; faculty, researchers, grad students, and sundry folks who just enjoyed the atmosphere of Harvard Square.

After graduating, I took the easy way out and stayed in Cambridge for my first postdoc at MIT. But with my spiffy new postdoctoral salary I could move across the river to the South End in Boston, landing in 02116.


A noticeably urban environment (thank God), one with a healthy dose of post-high-school students lurking around (not exactly sure why), certainly youthful but not like being in college any more.

But alas, the academic wheel of fortune turns in mysterious ways, and my next stop was at the Institute for Theoretical Physics in Santa Barbara. As I hoped to be spirited away by an attractive faculty offer at any moment, I chose not to bother to find a place in SB proper but rather live in Isla Vista, 93117.


IV is an entire municipality surrounded on three sides by the UCSB campus and on the fourth by the Pacific Ocean; nobody in their right mind lives there but students and surfers. Not an environment devoted to the life of the mind, but the weather was awfully nice.

Finally I was spirited away to the Windy City, where I live in the Lakeview section of Chicago, 60613.


Truly in my yuppie-metrosexual element, short on students but heavy on post-college strivers making the gradual transition from apartments to condos. And yes, there does seem to be some sort of upper age limit. I wonder where they all go? And will they drag me physically away, or is it a more subtle mind-control sort of thing?

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