Recent research has cast doubt on the potential for various electoral reforms to increase voter turnout. In this article, we examine the effectiveness of preregistration laws, which allow young citizens to register before being eligible to vote. We use two empirical approaches to evaluate the impact of preregistration on youth turnout. First, we implement differencein-difference and lag models to bracket the causal effect of preregistration implementation using the [2000][2001][2002][2003][2004][2005][2006][2007][2008][2009][2010][2011][2012] (Bennion and Nickerson 2011;Hanmer et al. 2010;Herrnson et al. 2008;Niemi et al. 2009;Ponoroff and Weiser 2010). While it was once commonly assumed that reducing legal obstacles to voting would inevitably lead to higher turnout (Burnham 1987;Lijphart 1997; Powell 1986; Wolfinger and Rosenstone 1980) We wish to thank the National Science Foundation (Grant #SES-1416816) for their generous support for this project. In addition, we wish to thank Barry C. Burden, Michael McDonald, Steven A. Snell, and three anonymous reviewers for their valuable feedback. Finally, we wish to thank Matthew Tyler for his invaluable work as a research assistant. Data and code for replicating our results can be found in the AJPS Data Archive on Dataverse (http://dvn.iq.harvard.edu/dvn/dv/ajps). depress political engagement (Burden et al. 2014). As one scholar succinctly put it, "non-participants are not likely to flood the polls simply because registration barriers diminish" (Timpone 1998, 155).An electoral reform that has nonetheless gained momentum in recent years is preregistration, whereby individuals younger than 18 are able to complete their registration application so that they are automatically added to the registration rolls once they come of age. Preregistration laws have been implemented in a dozen states, debated in at least 19 others in the last 5 years, and proposed in the U.S. Congress (2004). The policy is of particular salience and controversy in North Carolina, where preregistration was implemented with wide bipartisan support in 2009 and then abruptly repealed 4 years later by a newly elected Republican majority in the state legislature.1 Allegations swirled that the repeal was an attempt to impede future turnout among young voters, who had disproportionately voted Democratic in the 2012 election.2 On both sides of the aisle, policy makers seemed to assume that preregistration would increase youth Furthermore, recent scholarly research evaluating other electoral reforms offers a rather bleak outlook for the potential to increase citizen engagement through institutional changes. In this article, we estimate the causal effect of preregistration on youth turnout using two complementary approaches. First, using a nationally representative, pooled cross-section from the 2000-2012 Current Population Survey, we implement a difference-in-difference approach. We supplement this with lag models to create bracketed estimates of preregistration's impact (Angrist and Pischke 2008;Manski 1990...