The most important element in every election is the voters, and get-out-the-vote (GOTV) campaigns can make the difference between winning and losing. With the first two editions of Get Out the Vote , Donald P. Green and Alan S. Gerber broke ground by introducing a new scientific approach to the challenge of voter mobilization and profoundly influenced how campaigns operate. Get Out the Vote has become the reference text for those who manage campaigns and study voter mobilization. In this expanded and updated edition, Green and Gerber incorporate data from more than 100 new studies, which shed new light on the cost-effectiveness and efficiency of various campaign tactics, including door-to-door canvassing, email, direct mail, and telephone calls. Two new chapters focus on the effectiveness of registration drives and messaging tactics. The new Get Out the Vote will be available as the country gears up for the 2016 presidential campaign. This readable, practical guide on voter mobilization is sure to be an important resource for consultants, candidates, and grassroots organizations, as well as a valuable teaching tool in courses on campaigns and elections.