How much turnout did each extra layer of watching buy in Michigan in 2006?

In the August 2006 Michigan primary, registered voters whose mail promised to show their neighbors whether they had voted turned out at 37.8 percent, against 29.7 percent for voters who received nothing. That 8.1-point gap comes from Alan Gerber, Donald Green and Christopher Larimer’s 2008 American Political Science Review experiment on social pressure, and it was larger than the effect of any mailing that had been tested at that time.

The headline number is the part that gets repeated. The part that gets skipped is the staircase underneath it, because the four mailings were built so that each one added exactly one more way of being seen.

The four mailings and who got them

The sample was 180,002 Michigan households, 344,084 individuals, all registered voters who had cast a ballot in November 2004. About 100,000 households received nothing. Four groups of roughly 20,000 each got one postcard apiece, mailed shortly before the primary, which the authors priced at 30 cents each to print and send. Turnout was then read from public records.

Each card moved one step up a ladder of exposure, in the paper’s own descriptions. The first, labelled “Civic Duty,” said only “Remember your rights and responsibilities as a citizen. Remember to vote.” The second told households “YOU ARE BEING STUDIED!” and said their behavior would be examined through public records, while promising that the researchers would neither contact them nor disclose whether they had voted. The third, “Self,” said that who votes is public information, listed the household’s record for the 2004 primary and general elections, and stated “we intend to mail an updated chart” after the primary. The fourth, “Neighbors,” did the same but listed the records of people living nearby too, so that household members would know their neighbors’ records and the neighbors would know theirs.

What each added layer of observation bought

Using the paper’s Table 2, turnout was 29.7 percent for the control group (191,243 individuals), 31.5 for the civic-duty reminder, 32.2 for the “we are watching” mailing, 34.5 for Self and 37.8 for Neighbors. Differences between neighboring rungs are the useful thing to read:

Step up	Added ingredient	Gain over previous rung
Nothing to civic-duty reminder	A norm, stated	+1.8 points
Reminder to “we are watching”	Researchers will look at records, no one else will	+0.7
“Watching” to Self	The household’s own record is shown, with a promise to update it	+2.3
Self to Neighbors	Neighbors’ records shown too	+3.3

Two things stand out. A private reminder and a private audit together bought 2.5 points. Exposure to other people bought another 5.6 on top. And the single smallest step was the one that most resembles the folk idea of accountability, being told you are under observation by someone who will not tell anyone. Observation by a party with no social tie to you did something, but little.

The authors present the “we are watching” card as a test of whether mere observation moves behavior. Its small effect is consistent with the idea that being known to people you will meet again does most of the work, but that reading is mine, not a result. No arm held the audience fixed while varying the surveillance, so the data cannot say whether households reacted to the neighbors, to the explicit comparison, or to the longer card.

On the authors’ accounting, the Neighbors card produced 3,106 additional ballots at about $1.93 each.

The calls from recipients who minded

The paper contains one sentence on this, in its discussion of the cost of enforcing norms: many recipients of the Neighbors message called the phone number printed on the mailing and demanded to be removed from future lists. It gives no count. What it does show is that the strongest arm was also the one people objected to most visibly.

Later work found the backlash can be measured. Richard Matland and Gregg Murray exposed 580 people in Lubbock County, Texas, to mock campaign materials, as reported by PsyPost in 2013, and the participants shown a postcard with their hypothetical voting history said they felt angrier and more afraid, were more likely to say they would complain to the campaign, and were less likely to support the candidate. The study measured stated reactions to hypothetical mail, so it speaks to the cost of using this on voters a campaign wants to keep, not to turnout.

Shame, or something gentler

The same trio tested the emotional ingredient directly. In a 2010 Political Behavior paper, Gerber, Green and Larimer mailed 369,211 Michigan registrants who had voted in just one of two recent elections. A mailer reporting a past abstention raised turnout 6.3 points; one reporting a past ballot raised it 4.0. The 2.3-point difference (standard error 0.9) means pointing at the lapse beat pointing at the success, though praise still worked. The authors say they could not measure the emotions themselves, so “shame” versus “pride” remains a label for the wording, not a confirmed feeling.

The same card in louder elections

A 2016 working paper by Gerber, Huber, Fang and Gooch tested the Self mailer on 1.96 million people across 17 states in high-salience 2014 elections. Their card also compared each person’s history with the median registrant’s. Turnout rose 0.7 points, or 2.2 percent, an effect the authors call consistent across states and across subjects with different baseline turnout. They framed this as answering the worry that the Michigan result was an artifact of a quiet primary and of publication bias. The answer is partly: the direction held, but the size fell from 4.9 points to 0.7. Why it shrank is not something that comparison can settle, since the card, the election and the population all changed.

What carries over to a daily habit, and what does not

The social pressure mailing worked on a single act, once, with a hard deadline, on a behavior whose record already exists in a public file. Nobody had to be convinced that “we will check” was true. Voting history in the United States is a matter of public record, and the sender could verify it for $6,000. A daily act has none of those properties. There is no state file listing who rose at 6:10 on Thursday, no postcard that arrives after the fact, and a viewer who has already seen forty uneventful mornings stops looking.

What plausibly carries over is narrower than the popular summary suggests. The gradient says that the audience’s identity matters more than the existence of an audience: researchers who promised silence added 0.7 points, people living on your street added 3.3. Home energy research points the same direction, as in the Allcott and Schultz neighbor comparisons. The visible-record logic also fits the cases catalogued in five ordinary places where a lapse is visible. And it pairs awkwardly with the mere-measurement literature, where a private question about intent sometimes moves behavior and sometimes, in replications, does not.

What does not carry over is the size. Even for a once-a-year act with public records, the Self effect fell by more than eighty percent when the contest got louder. And nothing in these papers speaks to the same person being watched every day for months, so whether a friend group’s attention outlasts a postcard’s is an open question here, not a finding.