Gaby Goldstein, SDAN Director of Research;
Mallory Roman, SDAN Associate Director of Research
We ran a randomized controlled trial to determine if the receipt of a handwritten postcard a week after the receipt of an official voter registration form increased the odds of people completing & returning the voter registration form, as compared to the odds of return among people who did not receive a postcard.
Handwritten postcarding has become an incredibly popular voter outreach tactic among progressive volunteers, with volunteer postcarding groups all over the country. However, there is still very little research on the efficacy of postcarding, especially looking beyond voter turnout effects to effects on registration or candidate choice.
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 September 2018 (September Study). These postcards were sent in conjunction with 3 of VPC’s voter registration programs, which sent pre-filled official voter registration forms to all of the people included in this experiment. This study was a replication of our March 2018 voter registration postcarding experiment, except that the present study design included chaser postcards only, and targeted recipients of 2 additional VPC programs.
In the September Study, receiving a handwritten chaser postcard after receipt of a pre-filled voter registration form had a positive impact on the odds that a person would return their materials. But unlike the March Study, the effect was only marginally statistically significant (p=0.071), after controlling for individual-level variables like age, gender and race/ethnicity. On its own, these data cannot be generalized outside of this Study, but as a replication of the March Study it generally appears to confirm the March findings that chaser postcards boost registration form return rates.
The postcard chaser appears to work particularly well among people who had been registered before and just recently moved to their new address (“Movers”). This population was not included in the March study.
The results of the two studies taken together indicate that postcarding in conjunction with the voter registration forms reliably produces an increase in the gross amount of registered voters. However, that effect is likely small due to the powerful influence of other factors like age and gender, and may or may not rise to statistical significance depending on the number of people in the study.
This study helps to establish reliability for SDAN’s voter registration postcarding findings from March, and further suggests that postcarding as an add-on tactic for another voter registration effort may provide a meaningful bump in voter registration. For future research, we will build on the statistically significant finding in the Movers group, and will continue to look at groups like Movers to determine how to best reengage folks who have been registered previously and others who may be more likely to register.
A more detailed report of these findings can be found here.
SDAN’s commitment: It is SDAN’s intention to provide as much context as possible to allow for the nuanced interpretation of our data. SDAN’s convention is to contextualize effects by reporting p values, confidence intervals, and standardized/contextualized effect sizes for all models tested. Additionally, SDAN always differentiates between planned and exploratory analyses and a priori and post hoc tests, and reports the results of all planned analyses regardless of statistical significance. The findings reported here were informed by similar analyses in previous studies that were peer-reviewed a subset of the Sister District Data and Research team composed of senior-level statisticians called the Quantitative Advisory Committee. If you are interested in joining the Quantitative Advisory Committee please email Mallory.