Do text messages increase voter registration? Evidence from RCTs with a local authority and an advocacy organisation in the UK

Abstract

In the wake of the Covid-19 pandemic, text messages have become an increasingly attractive tool of voter registration. At the same time, in countries without automated registration, advocacy organisations play a more prominent role in supplementing the efforts of official bodies in registering voters. However, most available, robust evidence on whether voter registration campaigns work is based on campaigns conducted by official bodies charged with electoral registration. We present the results of two RCTs that aimed to increase voter registration in the UK using SMS-text messages, relying mainly on behavioural messaging. One was conducted by a local authority, while the other was implemented by an issue advocacy organisation that had no prior involvement in voter registration. In line with previous findings, the local authority’s text messages resulted in an increased registration rate of eight percentage-points, which translates into a three percentage-point increase in voter turnout. However, the advocacy organisation’s text messages neither increased voter registration, nor turnout, no matter whether the text message offered a personal follow-up conversation, or not. Given that many voter registration campaigns are run by advocacy organisations and text messages are an increasingly important mobilisation tool, this raises questions about the scope conditions of existing findings.