Do Robotic Calls from Credible Sources Influence Voter Turnout or Vote Choice? Evidence from a Randomized Field Experiment

The effectiveness of prerecorded phone calls was assessed in the context of a Texas Republican primary election that featured a contest for state Supreme Court. Automated calls endorsing one of the judicial candidates were recorded by the sitting Republican governor and directed at more than a quarter million people identified as likely voters and probable supporters of the governor. Two experimental designs were used to evaluate the calls’ effectiveness. The first design randomly assigned households to treatment and control conditions in order to gauge the calls’ effects on individuals’ voter turnout, as measured by public records. The second design randomly assigned precincts to treatment and control conditions in order to assess whether the calls increased the precinct level vote margin of the endorsed candidate. Results suggest that the automated calls had weak and statistically insignificant effects on turnout and vote margins.