Political parties struggle to recruit volunteers and to broaden the demographic makeup of activists. This research partnered with a major Dutch party to test whether outreach mode affects members’ willingness to sign up as volunteers. The central contribution is experimental evidence comparing personal phone calls that allowed members to voice opinions with emails, using two field experiments run before the 2021 national and 2022 municipal elections.
Field experiments with party members Volunteer sign-up as outcome Greater effects for younger members
Data and methods
The authors report two randomized field experiments conducted with a single large political party in the Netherlands, targeting over 35,000 party members ahead of the 2021 general and 2022 municipal elections. Party members were randomly assigned to receive a personal call, an email, or both. The pre-registered outcome reported in the abstract is members’ subsequent sign-up as volunteers. The abstract describes the interventions and randomized assignment but does not provide further measurement or analytic details.
Main findings
According to the abstract, receiving a personal call that allowed members to voice their opinions increased volunteer sign-up rates in both Studies 1 and 2, while emails had no effect. The reported effects were larger among younger members, and the authors frame these results as clarifying mixed prior evidence by highlighting the role of voice opportunities in recruiting and diversifying activist bases.
- Calls increased volunteer sign-up in both experiments; emails showed no impact.
-Effects were especially pronounced among younger members, per the abstract.
