Does public broadcasting increase voter turnout? Evidence from the roll out of BBC radio in the 1920s

There is reason to believe that exposure to public broadcasting can positively affect voter turnout, but these effects are hard to empirically disaggregate. This paper examines the geographically delimited roll out of BBC radio in England, which coincided with successive off-cycle general elections in the 1920s. Combining spatially interpolated census data with constituency-level electoral returns, a matched difference-in-differences design finds that turnout increases with radio exposure. This finding is supported by qualitative examination of the roll out alongside a range of robustness checks. The study makes a contribution to the literature on media and voting behaviour, while enhancing our understanding of how the BBC shapes electoral behaviour in Britain.