Finally, and most notably, Group 4 received the civic duty reminder, plus a list of their neighbors voting histories — all public information. They were asked What if your neighbors knew whether you voted This group voted at a rate of 37.8 percent — almost 8 percent more than the control group. A good part of the explanation seems to lie in the power of social norms. Its possible that people simply felt that they were a little more attuned to their civic duty norm of participation once they had the sense they were compiling a track record, and I think that probably had a pretty substantial effect on their incentive Gerber said, suggesting that these mailings might prick the civic conscience of a voter
