Our initial sampling frame was all registered, but formally unaffiliated, voters listed in the Connecticut voter file. We eliminated from this list all records where telephone or address records were invalid or inconsistent. We also removed records where the address or telephone number appeared three or more times in the voter file to make it easier to target specific individuals and to avoid temporary housing where respondents were more likely to have moved. We focused our sample on voters we believed to be more amenable to partisan conversion: Those who were younger (18–49, inclusive) and had recently participated (who voted in any election in 2006, 2004, or 2002 or were less than 21 and had registered after 2000).
We sent a treatment letter to a 50% random subset of the experimental participants (A test of random assignment appears in Table A1 in the online Appendix, in which we demonstrate that observable features of respondents in the treatment and control groups cannot explain treatment assignment).
We mailed letters on January 22, 2008 that reminded the recipient of the upcoming election and explained the need to affiliate with a party in order to participate in the party's presidential primary... the letter provides voters with information about their registration status, the upcoming primary, and the need to register with a party to participate in the primary.
Party identification,party registration,turnout,political attitudes