Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I say who wrote them.
Davenport, Tiffany C. 2010. Public Accountability and Political Participation: Effects of Face-to-Face Feedback Intervention on Voter Turnout of Public Housing Residents. Political Behavior 32 (September): 337-368.
Here's a few things we know about voter turnout:
In the current special issue of Political Behavior (background), Tiffany Davenport reports a turnout experiment that considers all those things at once. For a treatment, she combines door-to-door canvassing with a social pressure tactic. For a target population, she attempts to mobilize the urban poor (Boston Public Housing) during a low-salience municipal election (Boston's November 2007 municipal elections).
Boston's November 2007 municipal elections had only 13.6% turnout--and that's as a percentage of registered voters. Moreover, most of the Boston Public Housing residents included in the study had not voted in the 2004 or 2006 elections. Davenport had her work cut out for her trying to mobilize this group for this election.
She tried two treatments. First, she sent canvassers with a traditional "get out the vote" appeal. Consistent with previous work, this produced a 9-12 percentage point boost in turnout relative to the control group.
For her second (and more important) treatment, she sent canvassers with an official-looking turnout record that they hand-delivered to each door (but without any sort of "get out the vote" appeal--just delivery of the document). If somebody handed you an official looking report showing whether you had turned out in the previous elections, you might get a little spooked into voting.
And it worked. Delivering these turnout reports boosted voting by 15-18 percentage points. The canvassers didn't threaten to publicize the turnout reports. They didn't attempt to shame non-voters. They just handed over a turnout report, making the recipient realize that their "private" turnout behavior was being monitored.
The lesson for campaign managers is simple: You don't have to use heavyhanded, intimidating factors to make social pressure work. You can raise turnout dramatically just by subtly reminding people that they're being watched.
Research on similar subjects