Does State Online Voter Registration Increase Voter Turnout?

Abstract

More and more states have been adopting online voter registration in recent years. Investigating the impact of the policy on voter turnout can inform policy-making and contribute to our knowledge of political behavior. Using the Current Population Survey (CPS) data between 2000 and 2014, I conduct a difference-in-difference analysis at the state level and then an instrumental variable regression at the individual level. The difference-in-difference analysis shows that online voter registration has no impact on voter turnout for the general population but does increase the turnout for young voters by about 1 percentage point. The effects of online registration on turnout for the younger voters are stronger in states with earlier registration closing dates and without same day registration. The user identification requirements of state online registration systems have heterogeneous impacts for the voters of different age groups. The instrumental variable regression shows that the upper limit of the impact of online registration on voter turnout is about 7 to 12 percentage points. This study contributes to the existing literature on electoral regulations by estimating the causal effect of a new, important election reform.