About a month ago I accidentally found out that the LW idea of quining cooperation is already studied in academia:
1) Moshe Tennenholtz's 2004 paper Program Equilibrium describes the idea of programs cooperating in the Prisoner's Dilemma by inspecting each other's source code.
2) Lance Fortnow's 2009 paper Program Equilibria and Discounted Computation Time describes an analogue of Benja Fallenstein's idea for implementing correlated play, among other things.
3) Peters and Szentes's 2012 paper Definable and Contractible Contracts studies quining cooperation over a wider class of definable (not just computable) functions.
As far as I know, academia still hasn't discovered Loebian cooperation or the subsequent ideas about formal models of UDT, but I might easily be wrong about that. In any case, the episode has given me a mini-crisis of faith, and a new appreciation of academia. That was a big part of the motivation for my previous post.
My feelings are the opposite. I become exceedingly pleased and amused to find that someone else did it first. Aside from it being instant vindication, it just makes me happy. I feel a sense of kinship knowing that someone, somewhere, had the same data I had and came to the same exact logical leap that I did. It's like we're research buddies across time.
Though I do feel silly and a little mad at myself when I've wasted a lot of time synthesizing something could have just researched instead.