Replication Data for: Understanding the Impact of the 2018 Voter ID Pilots on Turnout at the London Local Elections: A Synthetic Difference-in-Difference Approach

Do more restrictive voter identification (ID) laws decrease turnout? I argue that in the 2018 London Local elections this was the case. Bromley was the only borough out of 32 to pilot a more restrictive ID scheme. The scheme was assessed by the Electoral Commission and Cabinet Office but lacked a good estimate for the impact on turnout. Applying a synthetic difference-in-difference methodology, which has several benefits compared to traditional difference-in-difference methods, to ward-level turnout data from 2002 to 2018 I show that turnout was between 4.0 to 5.0 percentage points lower than otherwise would be expected. This indicates more restrictive ID laws can meaningfully limit turnout which has implications for future elections if governments chose to implement a more restrictive regime.