Gaby Goldstein, SDAN Director of Research;
Mallory Roman, SDAN Associate Director of Research
We ran a randomized controlled trial to determine: 1) if people who received a handwritten postcard encouraging voter registration, along with an official voter registration form from Voter Participation Center (VPC), in our March and Sept 2018 studies had higher odds of turning out to vote in the November 2018 general election; and 2) if the effect of those postcards differed based on whether or not those targets had returned the registration form sent to them by VPC earlier in the year.
The point of voter registration is to expand the pool of voters. But registered voters don’t always show up to vote, come election day. While little is known about the effect of postcarding on voter registration, even less is known about its downstream consequences for voting behavior.
Sister District Action Network (SDAN) and VPC partnered on two voter registration experiments in March and September 2018. In each, SDAN volunteers sent handwritten postcards to eligible, unregistered individuals living in Michigan, Arizona, and Pennsylvania. 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. You can read about the March study here and the September study here. The current analysis went a step further and looked at whether or not the targets of the March and September studies were more likely to vote in the general election in November 2018, and further, if the effect of the handwritten postcard on voter turnout was higher among people who had returned the pre-filled VPC registration form.
Overall, sending eligible, unregistered individuals a handwritten postcard encouraging them to register to vote had no effect on later voter turnout. However, there is some suggestive evidence that receiving a handwritten postcard encouraging the target to register to vote did provide an extra boost in voter turnout among people who returned the VPC registration form in order to register to vote. Both studies are underpowered, so it is possible that these effects would have risen to statistical significance in a larger sample (specifically a larger sample of people who registered to vote through the VPC+SDAN registration efforts).
— First, there are far fewer treatment participants (people who got a postcard) in the September sample than in the March sample, and as noted above, the March Study is already statistically underpowered.
— Second, there were more voters in the September Study sample than in the March Study sample. This indicates that people who registered closer to the election (unregistered people we targeted in September 2018) voted more than people who registered further out from the election (unregistered people we targeted in March 2018).
Beyond the initial effects on voter registration, this analysis helps us understand how postcarding alongside a voter registration effort may (or may not) affect the later choice to vote. Unsurprisingly, people who registered to vote during the VPC+SDAN registration efforts voted at a much higher rate than people who did not. This suggests that encouraging newly registered voters to vote may be a good area for future research. We will continue to look at the downstream voter turnout effects of other voter registration studies.
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. These findings were peer reviewed by an independent statistician.