June 23, 2019 📊How much do presidential primary debates matter?

Plus, more research on the death of "the economy, stupid" and the ideology of primary versus general electorates

Welcome! I’m G. Elliott Morris, data journalist for The Economist and blogger of polls, elections, and political science. Happy Sunday! Here’s my weekly email with links to what I’ve been reading and writing that puts the news in context with public opinion polls, political science, other data (some “big,” some small) and looks briefly at the week ahead. Feedback? Drop me a line or just respond to this email. 

Dear Reader,

This week, I wrote an article for The Economist on the importance of presidential primary debates. I want to briefly discuss it here and offer a couple of thoughts that didn’t make it into the piece. (Today’s main article will thus be shorter than usual, because I want you to read the underlying Economist article.)

I also enjoyed reading a paper on the breakdown between presidential vote choice and the state of the economy. If you read my work even semi-frequently, this will sound familiar to you. Rejoice; now there is even more academic research to digest!

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This Week's Big Question

How much do presidential primary debates matter?

Historically, they have medium-sized effects, but can sometimes have large ones. Because of the number of candidates in this year’s primary and unusual attention being paid at this point in a cycle, next week’s debate could indeed matter a lot.

Image: NPR.org; Win McNamee / Getty Images

Televised debates in presidential nominating contests can cause huge disruptions in candidates’ polling numbers. Such is the conclusion I draw in an article for The Economist, in print this week under the headline “Primary numbers”. Here is the lead graphic for the article:

I find that primary debates cause on average a 6% chance in candidates’ polling numbers. The conclusion comes from my analysis of a dataset of polling in nominating contest from 1976 to 2016 using a technique called Bayesian change-point analysis. All this means is that the averages I compute are much more resistant to change than are other approaches, such as a simple averaging, time-weighted averaging or even local regression. Thus, the approach is well-suited for detecting actual change in candidate support, rather than changes that happen due to random sample variance alone. This way, we can tell that the 6% average change that results from debates is real change.

However, two points that did not make it into the piece are worth noting. First, that changes in polling numbers can be much larger (a) in contests with many candidates and (b) when more people are paying attention. These are clear to most people who spend any time at all looking at primary polling. Variance in averages is higher when there is more support for leading candidates to consolidate when, inevitably, a debate proves the inability of some minor candidates (as is a probable result of next week’s debates). Events impact more voters when more voters are actively paying attention to the election (as is certainly the case with 2020).

So keep that in mind after next week’s first 2020 Democratic debate. It could matter a whole heck of a lot.

And now, the most notable stuff I read and wrote over the last week.

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Political Data

From me for The Economist: A large share of Republicans hold progressive economic views”

“About 19% of Republicans held economic policy positions closer to the average Democrat than the average Republican”, say the authors, while “just 9% of Democrats held economic positions closer to the average Republican”.

There are many Republicans an astute Democrat could target, they reckon. Only 71% of “economically left Republicans”—who make up about 7% of the electorate overall—have pledged their support for Mr Trump in 2020, compared to 90% of economically right-leaning Republicans. Furthermore, according to the report, Democrats made gains among left-leaning independents in the 2018 mid-terms which could amount to a one percentage point increase in vote share next year. Though small, this increase would have been more than enough to tip the scales against Mr Trump in Midwestern states in 2016.

Brian Schaffner on Twitter: The average primary voter is more of an ideologue than the average general election voter, but there is actually lot of ideological among the former (my commentary)

Basile Simon (Reuters): The Brexit rift splitting the Conservative Party

Theresa May and her team negotiated an agreement with the European Union for Britain’s exit from the bloc. But parliament rejected the deal three times in the first quarter of 2019. Seeking to break the impasse, lawmakers voted on 12 indicative, non-binding Brexit alternatives, none of which secured a majority.

Reuters has analysed the voting patterns of all 650 MPs. Votes were classified as either supporting or opposing the government’s position, as set out by the Conservative Party’s chief whip, Julian Smith, and whether they supported the indicative votes. MPs who abstained from a vote are marked as such.

Other Data and Cool Work

Emily Badger and Quoctrung Bui (The Upshot): Cities Start to Question an American Ideal: A House With a Yard on Every Lot

a number of officials across the country are starting to make seemingly heretical moves. The Oregon legislature this month will consider a law that would end zoning exclusively for single-family homes in most of the state. California lawmakers have drafted a bill that would effectively do the same. In December, the Minneapolis City Council voted to end single-family zoning citywide. The Democratic presidential candidates Elizabeth Warren, Cory Booker and Julián Castro have taken up the cause, too.

A reckoning with single-family zoning is necessary, they say, amid mounting crises over housing affordability, racial inequality and climate change. But take these laws away, many homeowners fear, and their property values and quality of life will suffer. The changes, opponents in Minneapolis have warned, amount to nothing less than an effort to “bulldoze” their neighborhoods.

Today the effect of single-family zoning is far-reaching: It is illegal on 75 percent of the residential land in many American cities to build anything other than a detached single-family home.

That figure is even higher in many suburbs and newer Sun Belt cities, according to an analysis The Upshot conducted with UrbanFootprint, software that maps and measures the impact of development and policy change on cities.

Political Science, Survey Research, and Other Nerdy Things

Sean Freeder: “It’s No Longer the Economy, Stupid: Selective Perception and Attribution of Economic Outcomes” (Working paper)

Using data from the American National Election Study, General Social Survey, and original survey experiments, I present evidence that the relationship between incumbent reelection and economic performance has weakened considerably. I argue that the decline is explained by two psychological mechanisms for motivated reasoning: first, citizens are likelier to misperceive the economy if the alternative would mean acknowledging the seeming successes of the other party, or the apparent failings of their own. Second, even when citizens perceive the economy correctly, they often selectively attribute actual credit or blame for economic outcomes in a manner consistent with their partisanship. I present evidence not only that citizens regularly engage in selective perception and selective attribution, but that they trade off between the two depending on which, in a given election, requires the least cognitive effort for maintaining the perceived superiority of their own party.

What I'm Reading and Working On

I’m thinking about ways that we can make presidential nominating system better, be it revised participation rules, candidate qualifications, contest order or other such factors.

On a related note, I’m re-reading Francis Fukuyama’s Political Order and Political Decay: From the Industrial Revolution to the Globalization of Democracy, because I saw it at a second-hand book store for $6 and thought “why not”? (Don’t tell my SO; I already have too many books.) I promise I’m getting around to finishing a review of Jared Diamond’s Upheaval for you all… but man, it is very hard to force myself to read a book that I do not like.


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