A new paper by Alexandre Morozov and Alexander Feigel in PNAS offers a genuinely interesting evolutionary result. If each player in a population of Prisoner’s Dilemma agents carries an opponent-indexed cooperation probability — \(p_{c,i\to j}\), one entry per partner identity — then selection and mutation routinely produce cooperative configurations. The press release framed this as … Read more
NANCY — A few days ago I promised a dispatch on the keynote, and here it is. The eighth International Conference in Philosophy and Economics met this week in Nancy, and the keynote was given by my closest collaborator, who is also my wife, Maggie Penn. Her title was “Three Paradoxes of Optimal Evaluation.” I … Read more
BENEATH THE ENGLISH CHANNEL — Having just reoriented myself to turning my head to the right when about to cross the street, I have boarded the train at St. Pancras with Maggie, as we leave London and head to the 8th Conference on Philosophy and Economics in Nancy, France — via Paris, of course. There … Read more
LONDON — I came up out of the Underground this morning at the wrong station, a humbling way to begin a post about the meaning of position. The conference I am here for, the Warwick/Yale/Princeton meeting on political economy, takes its name, at one remove, from an English county whose old town lent its name … Read more
A new paper in Science — Gullich et al., “Recent discoveries on the acquisition of the highest levels of human performance” — looked at top performers in athletics, science, math, and music. The headline finding is one most parents would like to hear: among the highest adult achievers, peak performance is negatively associated with early … Read more
The previous post used the phrase “local data” something like thirty times. The phrase did most of the heavy lifting in the argument: local data does not determine global structure, the more holes the underlying object has the more slack between local and global, and so on. I want to start this post by interrogating … Read more
In 1867, the French mathematician Pierre Ossian Bonnet asked a question that sounds like it should have an obvious answer. If you know the metric of a compact surface at every point — the intrinsic distances and angles, the things you could measure if you were a tiny ant walking on the surface — and … Read more
Saturday night, Round 1, the Pittsburgh Steelers are on a video call with the wide receiver Makai Lemon. They hold pick 21. They are telling him, in front of cameras, that they intend to take him. Lemon, unflappable, accepts the news. Then his phone buzzes with another incoming call. The caller ID says Philadelphia. Why … Read more
A large strand of social network analysis treats triangles as special. Three people all connected to each other — a closed triad, a triangle in the graph-theoretic sense — show up in the literature as the minimum unit at which social structure is supposed to begin crystallizing. Triangles carry transitivity. They support trust. They coordinate … Read more