There is a cool article in the new American Political Science Review reporting the results of a field experiment in which different mailings were randomly sent to voters. It turns out that making voting turnout public knowledge has a dramatic effect on turnout -- here's the abstract:
American Political Science Review (2008), 102:33-48
Social Pressure and Voter Turnout: Evidence from a Large-Scale Field Experiment
Alan S. Gerber, Donald P. Green, and Christopher W. Larimer
Voter turnout theories based on rational self-interested behavior generally fail to predict signiﬁcant turnout unless they account for the utility that citizens receive from performing their civic duty. We distinguish between two aspects of this type of utility, intrinsic satisfaction from behaving in accordance with a norm and extrinsic incentives to comply, and test the effects of priming intrinsic motives and applying varying degrees of extrinsic pressure. A large-scale ﬁeld experiment involving several hundred thousand registered voters used a series of mailings to gauge these effects. Substantially higher turnout was observed among those who received mailings promising to publicize their turnout to their household or their neighbors. These ﬁndings demonstrate the profound importance of social pressure as an inducement to political participation.
Here's the key passage reporting their results, which show an eight percentage point increase in turnout from one mailing:
Here's a sample mailing:
While this might seem a little creepy, voting records are public information. It's important to remember that voting was an act performed in public before the Progressive Era -- a period when turnout was much higher than it is today.