Michigan Social Pressure Voting Mailer

Summary

The Michigan social pressure experiment produced the largest voter mobilization effect ever documented in a randomized study — 8.1 percentage points from a single mailer. The mechanism was social accountability: seeing that neighbors' voting records would be disclosed before and after the election activated compliance with an implicit civic norm. The experiment is as important for what it raised as for what it found. The effect was so large that it prompted immediate ethical debate: is it appropriate for civic organizations to use social pressure in democratic participation? The experiment created a new subfield of political science, was replicated over 100 times, and directly changed how campaigns, parties, and nonpartisan organizations approach voter mobilization.

Research question

"Does showing voters their own voting history alongside their neighbors' records increase turnout in a low-salience primary election?"

Methodology

Result

Positive

Social pressure arm: +8.1 percentage points vs. control; self-disclosure: +4.9 pp; Hawthorne: +2.5 pp; civic duty: +1.8 pp. Social pressure arm produced the largest GOTV effect ever recorded in a randomized study at that time.

Evidence strength

Strong

Randomized trial, replicated across multiple sites or studies.

Replication status

Replicated