This is the third of three posts this week on prediction markets. Monday was about information — the signal that travels before the message. Wednesday was about jurisdiction — the classification question that reproduces itself at every level you try to answer it. Today is about something prior to both: whether the classification of a … Read more
Naked Capitalism linked to Tuesday’s post, which brought some welcome new readers to this blog. For those arriving fresh: welcome, and this post is a good place to start — it’s the second in a series, but it’s written to stand on its own. In the last post, I wrote about work that Maggie and … Read more
This is the second of three posts this week on prediction markets. Monday’s post was about information — specifically, about what kind of signal moves through a prediction market before an official announcement arrives. Today’s is about jurisdiction. Friday’s will be about something more fundamental than either. On April 3, a federal judge in Arizona … Read more
Last week’s post ended with a theorem. This one starts with a dashboard. The theorem — Arrow’s impossibility result, applied to the aggregation problem that Simpson’s paradox creates — is on the record in All Measurements Are Local if you want it. The short version: when subgroup results conflict with each other and with the … Read more
This is the first of three posts this week on prediction markets. They can be read independently, but they build. Today’s question is about information. Wednesday’s is about jurisdiction. Friday’s is about ontology, which sounds worse than it is. Start with a fact pattern. In the weeks surrounding the Iran nuclear negotiations, large futures positions … Read more
Three items this week — all of them, in one way or another, about instruments that outlived their justifications. In the News The Toll Booth That Replaced the Threat Last week I noted that Trump’s serial extensions of the Strait of Hormuz deadline were doing something structurally distinct from simply moving the goalposts: each revision … Read more
This blog does not usually do “journal club.” (Ed: huh? …who “does journal club?” Is it voluntary?) It’s not that I have anything against academic journals — I publish in them, edit one, and spend a disproportionate fraction of my waking life reading them — but their timelines and their intended audience are different enough … Read more
There is a lot of noise about AI safety these days, and I want to contribute to it in a specific and, I hope, useful way. Maggie and I are spending this year at the Russell Sage Foundation working on, among other things, how to make our theoretical work on classifiers understandable to a broader … Read more
In a 2015 symposium on big data and measurement, Maggie Penn and I argued that social choice theory is central to the analysis of complex data precisely because any reduction of high-dimensional data into a usable measure involves aggregation, and aggregation involves choices about what to preserve and what to discard.1 We used the Florentine … Read more
Scientific American ran a piece yesterday on Simpson’s paradox — the phenomenon in which a trend that holds within every subgroup of a dataset reverses, or vanishes entirely, when those subgroups are combined. Regular readers of this blog will have encountered it before. In 2012, it showed up inside No Child Left Behind: a school … Read more