I have just resigned from the board of "Statistics and Computing", along with 17 other Associate Editors. This was a difficult decision: this great journal has published many tremendous articles under the leadership of EiC Ajay Jasra, and before him David Hand, Gilles Celeux, and Mark Girolami.

If there’s an issue Democrats could run on and win in a landslide, it’s anti-corruption. But first the Dem establishment needs to deal with its own corruption problem. It’s not enough to be right about Trump’s corruption—they also have to be credible.

Had a great time presenting Shiro Kuriwaki's and my new EI methods to EPSS in Belfast on Saturday! Our R package implementing all these methods (as well as partial ID bounds) is also now on CRAN! corymccartan.com/seine/

New R package on CRAN! ONNX is a runtime & file format for ML models. 'onnxr' lets you load & run models in about 2 lines of code! E.g. image detection running in ms from a pretrained model. Perfect for embeddings, smaller models, etc. And lots of .onnx available online! corymccartan.com/onnxr/

This take may ruffle some feathers. Not only do political parties expel members all the time, but the ability to do so is absolutely crucial for maintaining political cohesion and protecting against demagogic capture. Like would anyone on this platform object if the Democrats expelled Fetterman?

Few people are putting this so plainly. This is what is happening. Miss me with partisanship, as if partisanship isn't a vessel for achieving policy goals — including racial ones

So I urge you to look at the folks who will inevitable call for us to privatize social security in the wake of this report and check for the overlap with the folks who brought us the surging inequality and a sluggish economic recovery that got us here. 4/4

This is truly one of the worst things the court has done — both in terms of legitimacy and in terms of the law — since I have been covering the court.

Roberts court: "the mere fact of racially polarized voting is not relevant to proving racially polarized voting patterns"

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Another clear centering of Trump’s emotions from a few days ago: the number of headlines and articles that referred to E. Jean Carroll that referred to her as an “enemy” or “adversary” rather than “victim.”

Newly updated simple congressional model (tinyurl.com/cmchousemodel), now with LA map & recalibrated election model fit only to 2026-2024 data! Ds have lost 4 seats on avg to redistricting, but the loss grows to 5.6 seats in a D+6 environment. Ds 98% to win house in a D+6 environment, though

A small 🧵 about frustrations and opportunities w/ open-source research software for the social sciences: Came across a new paper in a top methods journal, explaining/demo'ing a new R package. Sounded v. cool, so was excited to dig in. What I found was largely a mess...

New old package on CRAN! 'adjustr' lets you do sensitivity analysis and small adjustments to a fitted Stan model without having to re-fit it, thanks to the magic of importance sampling! Wrote it as a PhD student but recently revised & updated with Stan changes. corymccartan.com/adjustr/inde...

This moment of extreme gerrymandering and diminishing voting rights has made it all the more urgent to press for big reforms in our democracy. Not only is this necessary; I'm increasingly convinced that it's achievable. democracyjournal.org/arguments/th...

If you do record linkage in #rstats, I'd love your feedback on irelink: Fast Probabilistic Record Linkage. It is a port of Python's splink package, rewritten with a clean, pipeable R interface. All of the magic happens in a database backend (default is DuckDB) so it's incredibly fast.

Very cool! Varying coefficient models directly applicable to ecological inference - should try this out in a many-covariate setting soon

This is also not quite true. Empirically, states with independent commissions or nonpartisan drawers produce maps that are at or near the median simulation on partisan + racial demographics. Because of that, it's reasonable to treat the median as a forecast for a drawer following only certain rules

This is not accurate! Just like polling, we can randomly sample maps in a representative way, and understand typical maps without looking at every one. We have mathematical proofs that these algorithms produce representative samples if run long enough.

Unfortunately some inaccurate info in this thread. The point of the NYT sims was to see what typical maps drawn without the VRA would look like. But the maps Stephen draws incorporate VRA compliance. Also wrong info on the algorithms which I will say more about separately

Not enough news coverage of how the insurrectionist reparations fund is a clear violation of the 14th Amendment. We need to enforce the Constitution in its original meaning and plain text. You can't imagine away parts of the Constitution just because it is politically inconvenient.

Our ALARM simulations and redistricting algorithm at work! Back in 2022 we released all the code to generate nationwide simulated maps exactly so that people could explore hypotheticals like this!

Our simulations show that the act isn’t needed for minority representation in the South, if partisan gerrymandering were checked. www.nytimes.com/2026/05/17/u...

The number of conservatives calling the compact Memphis-based TN-09 an "illegal racial gerrymander" has been insane. Whatever Alito wrote, the loud and clear signal was that even if Black people make up a majority of a coherent community, they aren't allowed to vote for their representation.

SCOTUS invoked the Purcell Principle, which is that courts shouldn't make changes that affect an election too close to an election, to block a decision that would have required Texas to change its maps *last December* but now since it advantages Rs it's fine to change maps after voting has started

“Just do in person” is absolutely going to be a substantial part of the answer, but it is sort of annoying the “just do bluebooks, so simple” thing wrt AI and teaching. like it’s a *lot* more complex than that. a lot of shit the modern classroom relies on will have to totally revamped.

A state that redraws its legislative maps before every election to maximize advantage for the incumbent party is not a democracy or a republic and in any case obviously violates the guarantee clause, among many others. No country does this. No country ever thought of doing this. It is a total farce.

It is mind boggling how messy and low quality so much data is. Companies whose entire job is to provide data will turn in shit that barely works.

Purcell Principle Calvinball.

The Bonica-Grumbach take is that electoral politics is volatile, uncertain, and doesn’t map well onto the left-right spectrum. What we’re more confident about are sincere, costly anti-corruptionism antiwar courtpackin & scotus term limits VRA & gerrymander ban pro act & card check dc & pr statehood

A month later, here is what happened to this work. blog.thecoatlessprofessor.com/posts/extrac... #rstats

University presidents have lost the plot. Try this: “The Faculty Senate Chair does not speak for the University. He gave his own views as he is not only entitled but encouraged to do even at official University events.” Why would any one person’s views represent the diversity of views at UMich?

New updates to our WP from Sept, including new validation of precinct-level conf intervals & a nonparametric test of the identifying assumptions (!). 'seine' software now supports these 'local' estimates + partial ID bounds + the new test!

Identification and Semiparametric Estimation of Conditional Means from Aggregate Data https://arxiv.org/pdf/2509.20194 Ecological inference is the challenge of estimating subgroup behavior using only aggregate data like geographic averages. This paper introduces a new semiparametric method 1/3

Wrote a piece for @slate.com on how our theories of partisan polarization gave the SCOTUS majority more intellectual cover to kill the VRA slate.com/news-and-pol...

New working paper on the California Fast-Food minimum wage (will come out as NBER WP soon but posting now). Big increase in wages. Big drop in separations. Little change in jobs. (Bonus: sheds light on QWI vs QCEW measurement of jobs.)

Still thinking about these instructions In the South, minority voters express “different” preferences over candidates by being Democrats and voting for Democrats (see work by Ansolabehere) If you control for party, you control away the biggest outcome of those different preferences

The decision in Louisiana v. Callais claims, "By 2004, the racial gap in voter registration and turnout had largely disappeared.... Black voters now participate in elections at similar rates as the rest of the electorate" (26–27). This is misleading: White turnout remains much higher than non-White.

Also: What a sad vision of democracy. These people think that race is only ever used instrumentally. They do not think people have the capacity to really care about access and representation above-and-beyond accruing power. They think everyone is as cynical as they are.

Everyone should be prepared for the current Supreme Court to strike down proportional representation bills (at the state or federal levels) and the John Lewis Voting Rights Act with bans on partisan gerrymandering and new pre-clearance. You need a Supreme Court management strategy too.

This:is 💯 correct. The vast majority of Section 2 litigation (and settlements made under the threat of litigation) have been at the local level. Callais will gut minority representation in city councils, county supervisors, and school boards across the county.

Given the argument that ended the VRA, I think it’s time liberals did some self reflection about the now decades long obsession with partisan polarization as the problem, as opposed to authoritarianism, extremism, oligarchy, and racism

The answer is proportional representation. Proportional representation enables equal representation to minority voters as a structural feature, not as a litigated favor any future court can take away.

It is now time to rethink the single-member district that makes racial gerrymandering possible now. We need a solution that does not rely on the Court.

The Court came for Section 2 of the Voting Rights Act today. The Callais decision renders Section 2 "all but a dead letter," in the words of Justice Elena Kagan. Plaintiffs now have to prove intentional discrimination. This is almost impossible.

I don't think much remains to be seen... hard to see how any Sec 2 districting suit could be successful (i.e., remedy dilution) if the state can insist on whatever partisan outcome it wants

The NYT calls it a 'blow' to the VRA, but Thomas and Gorsuch are clear on what the effects of the decision will be: "an end" to the "misadventure" of "roughly proportional representation" for minority groups.

The egregious decision in Rucho now lets SCOTUS punch a massive loophole for VRA §2: partisan goals can justify disparate racial impacts. This is about districting, but the same logic would let states resurrect literacy tests, etc. as long as the stated goal was partisan discrimination.

This is correct. There is no future of democratic self government in the US with an unreformed Supreme Court. The Court is riddled with corruption and abuses of power and rooting out that corruption is a sine qua non of civic democracy in the United States.