Sister District Study shows postcarding has strong effect on voter registration rates

As our Director of Research here at Sister District Action Network (SDAN), I’m so excited to share the results from our March 2018 postcarding experiment conducted in conjunction with the voter registration efforts of the Voter Participation Center (VPC). Overall, we found that our postcards significantly increased voter registration rates! Read on for more information.

To determine if the receipt of a handwritten postcard a week before or a week after receipt of an official voter registration form increased the odds of people completing & sending the voter registration form back to their Secretary of State.

Sister District Action Network (SDAN) partnered with the Voter Participation Center (VPC) to send handwritten postcards encouraging registration to eligible, unregistered individuals living in Michigan, Pennsylvania, and Arizona in March 2018. These postcards were sent in conjunction with VPC’s Voting Age Population Program, which sent official voter registration forms to these same people.

Key Findings:

  • The major finding of this study was that handwritten postcards sent after the receipt of voter registration materials (chasers) had a significant positive impact on the odds that a person would return their materials. Unregistered individuals had 20% higher odds of returning the completed form when they were sent a chaser, compared to the odds of returning the registration form after receiving the form alone (without a postcard). This finding achieved statistical significance (p=.009), after controlling for individual-level variables.
  • Sending a chaser was more effective than sending a postcard prior to receiving the registration form (i.e., a primer). But both target groups that received postcards completed their forms in higher numbers than the control group that did not receive any postcard. This means that receiving a postcard increased the odds of registration completion by about 14%. This finding also achieved statistical significance (p=.036), after controlling for individual-level variables.

Interesting Group Analyses:

  • Race. Asian and Caucasian people had the highest response rates, with both groups returning the largest percentage of registrations by race. Black, Hispanic, and Native American people all had much lower rates, indicating Asian and Caucasian people may have been especially motivated by the postcard in a way that other people were not. It is clear, however, that receiving a postcard after the receipt of the registration form produced the most successful registrations in all racial categories.

  • Age.  Age may also provide some interesting insights about postcard effectiveness. For voters under 25 and voters in the 50-64 age range, the utility of the postcard was minimal. However, for voters 25-39, who had the worst response rate overall, we saw a large increase due to receiving either postcard. We also saw a large increase in voters 65+, the group with the best response rate, when they received the postcard after the registration form. Similarly, people 40-49 also saw a boost from receiving a chaser postcard. This indicates that there may be especially large value in postcarding in conjunction with voter registration form receipt for voters 25-49 and over 65, but may not provide as much value for voters under 25 and between 50-64.


  • The SDAN+VPC postcard program significantly increased the number of people who successfully completed and submitted their voter registration form through the VPC VAP Program.
  • Sending a postcard after receiving the form was more effective than receiving it before.
  • Postcards were most effective in increasing registration completion among Asian and Caucasian Americans.
  • Postcards were most effective in increasing registration completion for individuals in the 25-39 and 65+ age ranges.
  • Caveat: these subgroup analyses (race and age) provide suggestive evidence about which groups responded best to postcards, but are not definitive evidence. More testing is required to gain a deeper understanding in order to understand how to best engage different groups.

SDAN’s Contributions:

  • SDAN volunteers purchased, completed, and mailed 57,259 postcards to eligible, unregistered individuals. Without your hard work, this experiment could not have been completed!
  • VPC has replicated these results and is now using the central findings in additional voter registration programs and contexts.
  • The results of this study are particularly impressive, considering our expectation of a low response rate due to the particular VPC program that was utilized.

Next Steps:

  • VPC is eager to continue working with SDAN. We are planning a follow-on postcarding experiment. This experiment will target a VPC program know to prompt the highest response rate, will replicate and further validate our results, and will continue to build on this encouraging preliminary work.
  • Note that this experiment tested the use of postcards to boost voter registration.  The study does not tell us about the utility of postcards to boost voter turnout. We will be planning experiments to test the use of postcards for voter turnout, to see if the encouraging results we’ve seen for voter registration extend to turnout. Stay tuned!

Gaby Goldstein
Director of Research
Sister District Action Network