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Archive of posts filed under the Political Science category.

Time series of Democratic/Republican vote share in House elections

Yair prepared this graph of average district vote (imputing open seats at 75%/25%; see here for further discussion of this issue) for each House election year since 1976: Decades of Democratic dominance persisted through 1992; since then the two parties have been about even. As has been widely reported, a mixture of geographic factors and […]

“Statistical insights into public opinion and politics” (my talk for the Columbia Data Science Society this Wed 9pm)

7pm in Fayerweather 310: Why is it more rational to vote than to answer surveys (but it used to be the other way around)? How does this explain why we should stop overreacting to swings in the polls? How does modern polling work? What are the factors that predict election outcomes? What’s good and bad […]

$ vs. votes

Carlos Cruz writes: Here’s an economics joke. Two economists are walking along when they happen to end up in front of a Tesla showroom. One economist points to a shiny new car and says, “I want that!” The other economist replies, “You’re lying.” The premise of this joke is that if the one economist had […]

“She also observed that results from smaller studies conducted by NGOs – often pilot studies – would often look promising. But when governments tried to implement scaled-up versions of those programs, their performance would drop considerably.”

Robert Wiblin writes: If we have a study on the impact of a social program in a particular place and time, how confident can we be that we’ll get a similar result if we study the same program again somewhere else? Dr Eva Vivalt . . . compiled a huge database of impact evaluations in […]

A Bayesian take on ballot order effects

Dale Lehman sends along a paper, “The ballot order effect is huge: Evidence from Texas,” by Darren Grant, which begins: Texas primary and runoff elections provide an ideal test of the ballot order hypothesis, because ballot order is randomized within each county and there are many counties and contests to analyze. Doing so for all […]

2018: How did people actually vote? (The real story, not the exit polls.)

Following up on the post that we linked to last week, here’s Yair’s analysis, using Mister P, of how everyone voted. Like Yair, I think these results are much better than what you’ll see from exit polls, partly because the analysis is more sophisticated (MRP gives you state-by-state estimates in each demographic group), partly because […]

“Law professor Alan Dershowitz’s new book claims that political differences have lately been criminalized in the United States. He has it wrong. Instead, the orderly enforcement of the law has, ludicrously, been framed as political.”

This op-ed by Virginia Heffernan is about g=politics, but it reminded me of the politics of science. Heffernan starts with the background: This last year has been a crash course in startlingly brutal abuses of power. For decades, it seems, a caste of self-styled overmen has felt liberated to commit misdeeds with impunity: ethical, sexual, […]

Hey! Here’s what to do when you have two or more surveys on the same population!

This problem comes up a lot: We have multiple surveys of the same population and we want a single inference. The usual approach, applied carefully by news organizations such as Real Clear Politics and Five Thirty Eight, and applied sloppily by various attention-seeking pundits every two or four years, is “poll aggregation”: you take the […]

2018: Who actually voted? (The real story, not the exit polls.)

Continuing from our earlier discussion . . . Yair posted some results from his MRP analysis of voter turnout: 1. The 2018 electorate was younger than in 2014, though not as young as exit polls suggest. 2. The 2018 electorate was also more diverse, with African American and Latinx communities surpassing their share of votes […]

2018: What really happened?

We’re always discussing election results on three levels: their direct political consequences, their implications for future politics, and what we can infer about public opinion. In 2018 the Democrats broadened their geographic base, as we can see in this graph from Yair Ghitza: Party balancing At the national level, what happened is what we expected […]

Why it can be rational to vote

Just a reminder.

“We are reluctant to engage in post hoc speculation about this unexpected result, but it does not clearly support our hypothesis”

Brendan Nyhan and Thomas Zeitzoff write: The results do not provide clear support for the lack-of control hypothesis. Self-reported feelings of low and high control are positively associated with conspiracy belief in observational data (model 1; p

My two talks in Austria next week, on two of your favorite topics!

Innsbruck, 7 Nov 2018: The study of American politics as a window into understanding uncertainty in science We begin by discussing recent American elections in the context of political polarization, and we consider similarities and differences with European politics. We then discuss statistical challenges in the measurement of public opinion: inference from opinion polls with […]

“What Happened Next Tuesday: A New Way To Understand Election Results”

Yair just published a long post explaining (a) how he and his colleagues use Mister P and the voter file to get fine-grained geographic and demographic estimates of voter turnout and vote preference, and (b) why this makes a difference. The relevant research paper is here. As Yair says in his above-linked post, he and […]

“2010: What happened?” in light of 2018

Back in November 2010 I wrote an article that I still like, attempting to answer the question: “How could the voters have swung so much in two years? And, why didn’t Obama give Americans a better sense of his long-term economic plan in 2009, back when he still had a political mandate?” My focus was […]

What does it mean to talk about a “1 in 600 year drought”?

Patrick Atwater writes: Curious to your thoughts on a bit of a statistical and philosophical quandary. We often make statements like this drought was a 1 in 400 year event but what do we really mean when we say that? In California for example there was an oft repeated line that the recent historic drought was […]

MRP (or RPP) with non-census variables

It seems to be Mister P week here on the blog . . . A question came in, someone was doing MRP on a political survey and wanted to adjust for political ideology, which is a variable that they can’t get poststratification data for. Here’s what I recommended: If a survey selects on a non-census […]

Baltimore-Washington

Taking Amtrak, going through Baltimore, reminded that Baltimore used to be the big city and Washington was the small town. My mother worked for the government in the 1970s-80s and had a friend, Pat Smith, who’d moved to DC during WW2 when they were filling up all the government agencies. Pat told my mom that, […]

Vote suppression in corrupt NY State

I’ll be out of town on election day so I thought I should get an absentee ballot. It’s not so easy: OK, so I download the form and print it out. Now I have to mail it to the county board of elections. Where exactly is that? I find the little link . . . […]

David Brooks discovers Red State Blue State Rich State Poor State!

The New York Times columnist writes: Our political conflict is primarily a rich, white civil war. It’s between privileged progressives and privileged conservatives. You could say that tribalism is the fruit of privilege. People with more stresses in their lives necessarily pay less attention to politics. . . . I’ve had some differences with Brooks […]