[Yawrehto]

Really? That's odd. The typical zip code has a population of about ~9000. Dates of birth are about evenly distributed, so you'd still get about 24 people/birthday, or around 12 men or women per birthday per zip code.. I might be off by a fair amount in either direction, but I don't think I'd be twelve times off.

[snowwrestler]

Dates of birth are not evenly distributed.

To clarify: your date of birth includes the year. It’s more specific than your birthday, which we usually think of as just day & month.

[Terr_]

Also, the difficulty of identifying someone probably looks like a power-law curve, meaning that most of the "total difficulty" is concentrated in a small group, the ~13% that can't be identified.

In other words, even if one person is extraordinarily tricky to find [0], their share of the total un-findable-ness does not diffuse outwards to help anybody else.

[0] http://tailsteak.com/archive.php?num=433

[Yawrehto]

Oh, ok, I didn't realize that the data included the year. Never mind, I don't know the US age distribution well enough to have any idea of how plausible it is; I withdraw my comment.

[meindnoch]

birthday != date of birth