The Impact of Election Day Registration on Voter Turnout and Election Outcomes

It is widely believed that voter registration is a substantial barrier to voter participation in general, but particularly so for likely Democratic voters. A popular solution is election day registration (EDR), which eliminates the closing date by permitting registration at the polls. We posit a small positive effect of EDR on turnout and, contrary to conventional wisdom, theorize that individuals most likely to take advantage of EDR are in fact Republican voters. We investigate the causal effect of EDR on turnout and the partisan vote distribution using a powerful natural experiment in Wisconsin. When EDR was implemented in Wisconsin, only municipalities that required registration were affected by the change in the law. Using the leverage afforded by this experiment we show convincingly that EDR did increase turnout in Wisconsin by about three points. We find that the introduction of EDR increased turnout but actually decreased the Democratic share of the twoparty vote for president by four to six points.