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Archive of posts filed under the Political Science category.

Analyze all your comparisons. That’s better than looking at the max difference and trying to do a multiple comparisons correction.

[cat picture] The following email came in: I’m in a PhD program (poli sci) with a heavy emphasis on methods. One thing that my statistics courses emphasize, but that doesn’t get much attention in my poli sci courses, is the problem of simultaneous inferences. This strikes me as a problem. I am a bit unclear […]

Incentives Matter (Congress and Wall Street edition)

[cat picture] Thomas Ferguson sends along this paper. From the summary: Social scientists have traditionally struggled to identify clear links between political spending and congressional voting, and many journalists have embraced their skepticism. A giant stumbling block has been the challenge of measuring the labyrinthine ways money flows from investors, firms, and industries to particular […]

Time-sharing Experiments for the Social Sciences

Jamie Druckman writes: Time-sharing Experiments for the Social Sciences (TESS) is an NSF-funded initiative. Investigators propose survey experiments to be fielded using a nationally representative Internet platform via NORC’s AmeriSpeak® Panel (see http:/ for more information). In an effort to enable younger scholars to field larger-scale studies than what TESS normally conducts, we are pleased to announce a Special […]

Statistical Challenges of Survey Sampling and Big Data (my remote talk in Bologna this Thurs, 15 June, 4:15pm)

Statistical Challenges of Survey Sampling and Big Data Andrew Gelman, Department of Statistics and Department of Political Science, Columbia University, New York Big Data need Big Model. Big Data are typically convenience samples, not random samples; observational comparisons, not controlled experiments; available data, not measurements designed for a particular study. As a result, it is […]

UK election summary

The Conservative party, led by Theresa May, defeated the Labour party, led by Jeremy Corbyn. The Conservative party got 42% of the vote, Labour got 40% of the vote, and all the other parties received 18% between them. The Conservatives ended up with 51.5% of the two-party vote, just a bit less than Hillary Clinton’s […]

You’ll never guess this one quick trick to diagnose problems with your graphs and then make improvements

The trick is to consider graphs as comparisons. Here’s the story. This post from several years ago shows a confusing and misleading pair of pie charts from a Kenyan election: The quick reaction would be to say, ha ha, pie charts. But that’s not my point here. Sure, pie charts have problems and I think […]

U.K. news article congratulates YouGov on using modern methods in polling inference

Mike Betancourt pointed me to this news article by Alan Travis that is refreshingly positive regarding the use of sophisticated statistical methods in analyzing opinion polls. Here’s Travis: Leading pollsters have described YouGov’s “shock poll” predicting a hung parliament on 8 June as “brave” and the decision by the Times to splash it on its […]

Try asking someone in the real estate business

This came in the email: Dear Professor Gelman, Hi. My name is ** and I am a 5th grade student at ** School in **, NY. I am in Mr. **’s class and we are working on our graduating project called Capstone! I am studying how how President Trump’s business life affects his job as […]

Mike Bostock graphs federal income tax brackets and tax rates, and I connect to some general principles of statistical graphics

Mike “d3” Bostock writes: Regarding the Vox graph on federal tax brackets, here is a quick-and-dirty visualization of effective tax rates for a given taxable income and year. However, there is a big caveat: estimating the effective tax rate based on actual income is much harder since it depends on the claimed deductions. This could […]

Taxes and data visualization

Nadia Hassan writes: Vox has a graph of tax rates over time. Their visualizations do convey that tax rates for high earners have declined over time and tax brackets are fewer now, but it seems like there are more appealing and intuitive ways to display that. I agree. This visualization reminds me a lot of […]

Support for presidential candidates at elite law firms in 2012 and 2016

Paul Campos writes: Thought these data were extreme enough to be of general interest. OK, before you click on the link, here’s the story: Campos looked up the presidential campaign contributions at 11 top law firms. (I’m not sure where his data came from; maybe the same source as here?) Guess what percentage of contributions […]

San Francisco housing debate: A yimby responds

Phil Price recently wrote two much-argued-about posts here and here on the yimby (“yes in my backyard”) movement in San Francisco. One of the people disagreeing with him is Sonja Trauss, who writes: Phil makes a pretty basic mistake of reasoning in his post, namely, that the high income residents of the proposed new housing […]

The Other Side of the Night

Don Green points us to this quantitative/qualitative meta-analysis he did with Betsy Levy Paluck and Seth Green. The paper begins: This paper evaluates the state of contact hypothesis research from a policy perspective. Building on Pettigrew and Tropp’s (2006) influential meta-analysis, we assemble all intergroup contact studies that feature random assignment and delayed outcome measures, […]

How is a politician different from a 4-year-old?

A few days ago I shared my reactions to an op-ed by developmental psychologist Alison Gopnik. Gopnik replied: As a regular reader of your blog, I thought you and your readers might be interested in a response to your very fair comments. In the original draft I had an extra few paragraphs (below) that speak […]


I think there’s something wrong this op-ed by developmental psychologist Alison Gopnik, “4-year-olds don’t act like Trump,” and which begins, The analogy is pervasive among his critics: Donald Trump is like a child. . . . But the analogy is profoundly wrong, and it’s unfair to children. The scientific developmental research of the past 30 […]

What’s the deal with the YIMBYs?

This post is not by Andrew. It is by Phil. There’s at least one thing people in San Francisco seem to agree on: the rent is too damn high. The median rent is between about $3000 and $3500 per month…for a one-bedroom apartment. High-tech workers and upper-echelon businesspeople can afford a place, but baristas and […]

Mockery is the best medicine

[cat picture] I’m usually not such a fan of twitter, but Jeff sent me this, from Andy Hall, and it’s just hilarious: The background is here. But Hall is missing a few key determinants of elections and political attitudes: subliminal smiley faces, college football, fat arms, and, of course, That Time of the Month. You […]

“Everybody Lies” by Seth Stephens-Davidowitz

Seth Stephens-Davidowitz sent me his new book on learning from data. As is just about always the case for this sort of book, I’m a natural reviewer but I’m not really the intended audience. That’s why I gave Dan Ariely’s book to Juli Simon Thomas to review; I thought her perspective would be more relevant […]

What’s the difference between the French and U.S. presidential elections? Political parties.

Consider a national election with the following four major candidates, from right to left: – Populist far-right nativist – Religious conservative – Center-left technocrat – Populist anti-corporate leftist In the first round of the 2017 French presidential election, these four candidates received 21%, 20%, 24%, and 20%, respectively. In the United States, these candidates were […]

The Aristocrats!

[cat picture] I followed a link from Tyler Cowen to the book, “Inside Job: How Government Insiders Subvert the Public Interest,” by Mark Zupan (but not this Mark Zupan, I think). The link points to the book’s Amazon page, and here’s the very first blurb: ‘In the tradition of Parkinson’s Law, this fascinating and novel […]