[jtanderson]

Wow, yeah. Came here to say the same. I could understand somewhat making a distinction between emails that end in .edu and those who don't -- at least during the early days -- but this system does seem excessive.

I do think the ideas in the paper are pretty cool! One question: have you considered or attempted some sort of generative models based on this system? You'd have to do some clever symbolic manipulations to deal with the "infinities" that crop up, but it seems like it could be interesting.

[sampo]

> emails that end in .edu

Only universities in the United States have emails that end in .edu. Most of the universities in the world have domain names that end with their respective country code.

[gpm]

> Only universities in the United States

Not strictly speaking true. Univeristy of Toronto (Canada) will give you a toronto.edu email if you're a CS student (even undergrads) or faculty.

[xamuel]

Not sure what you mean exactly by "generative models" but it reminds me of Rohde et al 2004 (https://www.nature.com/articles/nature02842) which is all about modelling this sort of thing. In fact, some of the results of Rohde's paper are quantitative things which Rohde et al discovered by simulation and which my paper provides theoretical explanation for (see my paper's Proposition 6 and the last sentence of the abstract of Rohde et al).