From the Election Updates Blog at the California Institute of Technology, known as Caltech for short. The Election Updates Blog is produced by election tech experts Michael Alvarez, Lonna Atkeson, Paul Gronke, Thad Hall, Robert Krimmer, and Charles Stewart III:

Since the movement towards online voter registration began years ago, there’s been discussion among academics, advocates, and election officials about whether online voter registration will boost voter turnout.

There’s a new research article published electronically in Social Science Quarterly, by Jinjai Yu, that looks into this question. The paper, “Does State Online Voter Registration Increase Voter Turnout”, uses Census self-reported voter turnout data, looking at the potential association between the availability of online voter registration and voter turnout. To quote from the paper’s abstract:

The results of this study demonstrate that state online voter registration increases voter turnout. The difference‐in‐difference analysis shows that the states’ implementation of online voter registration increases the turnout of young voters by about 3 percentage points in presidential election years. The instrumental variable analysis shows that the usage of online registration by voters increases their turnout by about 18 to 20 percentage points.

According to the analysis reported in the paper, the availability of online voter registration seems to be especially important for younger citizens in presidential election years.