Davenport, Tiffany C., Alan S. Gerber, Donald P. Green, Christopher W. Larimer, Christopher B. Mann and Costas Panagopoulos (2010) "The Enduring Effects of Social Pressure: Tracking Campaign Experiments Over a Series of Elections," Political Behavior (32)3: 423-430. DOI 10.1007/s11109-010-9122-0
Recent field experiments have demonstrated the powerful effect of social pressure messages on voter turnout. This research note considers the question of whether these interventions’ effects persist over a series of subsequent elections. Tracking more than one million voters from six experimental studies, we find strong and statistically significant enduring effects one and sometimes two years after the initial communication.
Link to article here.