Traditionally the tactic involves writing to party supporters to suggest that using a postal vote would be more convenient and aid their participation, and to urge them to apply either online or via an enclosed application form.
Postal votes are increasingly popular. In the 1997 UK general election, 937,205 postal ballots were issued. By the 2017 general election, that figure had risen to more than eight million. The rise in postal voting has implications for the planning of electoral campaigns because of votes cast early.
However, in what is believed to be the first field experiment outside the USA into postal voter recruitment, Joshua Townsley of Kent’s School of Politics and International Relations and Stuart Turnbull-Dugarte (KCL) discovered that although political parties are increasingly looking for people to sign up to use postal votes in local elections, they need to consider the most effective ways of persuading people to do so.
Their experiment was conducted during the UK local elections in London in May 2018. A list of 3340 registered voters that the Liberal Democrat party identified as being likely supporters were randomly assigned to either a control or treatment group.
The responses to the approach about postal voting were compared using the official voter register and they found there was no substantive difference between the groups, with a near identical proportion registered to vote by post (16.87% in the control group and 16.84% in the treatment group).
Joshua Townsley said: ‘Easily accessible postal voting is rising in many countries, but the implications for electoral campaigns are under-researched. We tested whether letters and application forms sent to supporters worked, and despite them being widely used, we found they weren’t effective.’