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Reposted by Alex Coppock

Robert Simmon @rsimmon.bsky.social · 15d

Since it’s the #equinox, time to re-post the best #dataviz I’ve ever done: 365 pictures of the Earth from space, taken at exactly 6:00 a.m. Details on the NASA Earth Observatory: earthobservatory.nasa.gov/images/52248...

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Alex Coppock @aecoppock.bsky.social · 14d

Congratulations! Would love a 🧵 on this one!

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Alex Coppock @aecoppock.bsky.social · 20d

this part seems cool

Guided by our values and theory of policy design, Searchlight’s approach to policy will be defined by bold, persistent experimentation.

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Alex Coppock @aecoppock.bsky.social · 21d

I wish someone would rewrite my crappy extreme value bounds / trimming bounds package for attrition to have variance estimates and tidy / glance methods

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Alex Coppock @aecoppock.bsky.social · 22d

love this #notamap as a way of understanding the scale of land use. we're so used to seeing state borders and we have a rough sense of their relative sizes -- this plot makes great use of that

Conrad Hackett @conradhackett.bsky.social · 23d

Below is a clever visualization of the distribution of how land is used in the US. Cows roam over a lot of land!

But this is not a map - for example, the 100 largest landowning families aren't confined to Florida.

This is a cartogram depicting the share of land associated with various purposes in the United States.

From https://www.bloomberg.com/graphics/2018-us-land-use/#xj4y7vzkg

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Alex Coppock @aecoppock.bsky.social · 23d

Ooh I especially dislike when an author preregisters a bad analysis (like something that conditions on post-treatment variables) then says in response to reviewers that they can't remove it because PAP.

glad to know about the rigorous treatment of this "commitment bias" behavior!

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Alex Coppock @aecoppock.bsky.social · 23d

love this -- so very useful.

btw you *can* write your own handler as you did here (which is v. flexible and extensible) but you can also do many post-estimation things with the .summary argument if you like!

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Alex Coppock @aecoppock.bsky.social · 23d

The great Vincent Arel-Bundock shows how to use marginaleffects post-estimation summaries with DeclareDesign simulations!

Vincent Arel-Bundock @vincentab.bsky.social · 24d

The new {marginaleffects} release for #RStats (0.30.0) comes with two new vignettes:

1. Speed up computation with automatic differentiation (often 10x gains) marginaleffects.com/bonus/perfor...

2. Power analyses with {marginaleffects} and {DeclareDesign}. marginaleffects.com/bonus/power....

37 Performance – Model to Meaning

marginaleffects.com

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Alex Coppock @aecoppock.bsky.social · 23d

Lol hello elevator friends!

VAB has it right on both counts.

1. I ALMOST always describe the model in terms of POs, then calculate the estimand from them -- but you can also do a "structural model"

2. DD is happy with any DGP functions that make a data.frame, so if they make missing data...

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Reposted by Alex Coppock

Eunji Kim @eunjikim.bsky.social · 25d

Grateful to Matt Baum, Jamie Druckman, @jonmladd.bsky.social @brendannyhan.bsky.social @dannagal.bsky.social for joining the Author Meets Critics session on The American Mirage tomorrow at 12:00. If you spot me at the conference, ask for my favorite book merch: a custom magnetic bottle opener!

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Alex Coppock @aecoppock.bsky.social · Sep 7

yep, there's a bit of popping up and down...

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Alex Coppock @aecoppock.bsky.social · Sep 4

I'm once again a session chair for APSA and will be imposing the Nyhan / Samii rules. Encourage your chairs to do the same.

I don't see any good arguments for the usual

all papers
all discussant comments
all questions

format

Alex Coppock @aecoppock.bsky.social · Sep 3

I'm a session chair for APSA (Innovations in Experimental Design, 4pm at the Marriott!) and will IMPOSE this format.

90 minutes / 5 papers = 18 minutes a paper

10 minutes presentation [no time for lit review, friends!]
2 minutes discussant [praise + 1 good point]
6 minutes Q&A [2, maybe 3 Qs]

Brendan Nyhan @brendannyhan.bsky.social · Sep 3

For folks going to APSA - friends don't let friends use the horrible default panel format. Divide the time equally and open the floor discussion *after each talk*. Works SO much better as long as the chair enforces time limits. cyrussamii.com?p=1806

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Alex Coppock @aecoppock.bsky.social · Sep 3

wouldn't that be great?

methods classes are usually all about "tools" to answer research questions and only rarely mediations on the unanswerability of many research questions

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Alex Coppock @aecoppock.bsky.social · Sep 3

whaaaat!? that's so cool!

literally just:

weird_trick = D * X

iv_robust(weird_trick ~ D | Z)

to get the mean of X among compliers!

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Reposted by Alex Coppock

Per Engzell @pengzell.bsky.social · Sep 3

All statistical models are wrong, but some are stupid

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Alex Coppock @aecoppock.bsky.social · Sep 3

Suppose there are only two publication tracks for an experiment:

1) Pre-registered experiment:
PAP -> Realization -> Submit -> RR -> Publication

2) Registered report:
PAP -> Submit -> RR -> Realization -> RR2 -> Publication

when should we want 2 not 1?

to protect against "null risk"?

JJ @jj.mcdonough.rodeo · Sep 3

What's the issue with registered reports? They seem like a good idea on the surface, which is the depth of my knowledge.

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Alex Coppock @aecoppock.bsky.social · Sep 2

Interesting -- was the claim that ppl could sniff out a deepfake but now they can't?

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Alex Coppock @aecoppock.bsky.social · Sep 2

I'm souring on registered reports lately... but I love testing pipelines on simulated data!

Trouble is my simulated data is usually nice and clean... and it's the asymmetric *cleaning* that often flips a sign!

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Alex Coppock @aecoppock.bsky.social · Sep 2

"no hope of making scientific progress" is classically Mungerian, but I don't think he's right. If the value of some parameter varies over time, then we make scientific progress if we measure it repeatedly. He says academia is "too slow" for this; I think we just don't like to repeat experiments.

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Alex Coppock @aecoppock.bsky.social · Sep 2

It is *so hard* to fight this kind of asymmetry. Any suggestions or workflows you do to counteract?

Ryan Briggs @ryancbriggs.net · Sep 2

It's very human to only double check that a process is working when you get a weird result. It's also very bad practice, because sometimes your "right" result is due to a bad process and you will be misled. Social scientists (economists) do this kind of asymmetric checking.
arxiv.org/pdf/2508.20069

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Reposted by Alex Coppock

Rachel Porter @rachelporter.bsky.social · Sep 2

Notre Dame’s Department of Political Science is hiring *multiple* senior folks (assoc/full prof) working on democracy broadly (institutions, political behavior, CP, AP).

I’m not on the committee (hiding on research leave), but I'm happy to chat / answer questions!

👉 apply.interfolio.com/172986

Apply - Interfolio {{$ctrl.$state.data.pageTitle}} - Apply - Interfolio

apply.interfolio.com

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Alex Coppock @aecoppock.bsky.social · Aug 27

This post seriously conflates "polling" with "survey experimentation"

Also any paragraph that starts this way is a big 🚩

I know that correlation does not equal causation. But

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Alex Coppock @aecoppock.bsky.social · Aug 20

LESS looks like A LOT of fun -- now you've got one more reason to be happy you live in London or one more reason to be jealous of those who do!

Florian Foos @florianfoos.bsky.social · Aug 20

📢 Call for Papers – London Experimental Seminar Series (LESS) in Political Science @lsegovernment.bsky.social.
We are launching a new forum for experimental political science research: First seminar: 19/11/2025. Deadline: 31/08/2025. Submit here: forms.gle/ZUJcBbZoDoaY...

London Experimental Seminar Series in Political Science

We are inviting submissions for the London Experimental Seminar Series in Political Science (LESS), a new forum for discussing experimental political science research among researchers at London unive...

forms.gle

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Alex Coppock @aecoppock.bsky.social · Aug 7

Submitted!

EPSS @epssnet.bsky.social · Aug 7

We believe there’s room for multiple poli sci conferences in Europe, just like in the US & other regions.

🔝 But if you’re looking to support a Europe-based not-for-profit member-led organization, submit your work to 1️⃣ EPSS conference:

📍 Belfast
📅 18–20 June 2026
📝 epssnet.org/belfast-2026/

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EPSS 2026 Conference | June 18–20 | ICC Belfast, UK

Join top political scientists for the EPSS 2026 Annual Conference in Belfast. Submit papers, attend panels, and network with fellow researchers.

epssnet.org

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Alex Coppock @aecoppock.bsky.social · Jul 25

My sister is taking her post-tenure (WOO!!!) sabbatical trip to Nepal and will be blogging it!

Lizzie Coppock @lizzieloo.bsky.social · Jul 24

I have a sabbatical coming up and I'm going to Nepal! Why Nepal? You can read about it at my first blog post about this trip.

TL;DR: linguistic diversity, writing systems (and pretty scripts), classifiers, and a school for Newar kids in Kathmandu.

sites.bu.edu/lislab/2025/...

Field trip to Nepal! | Linguistic Semantics Lab (LiSLab)

sites.bu.edu

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