We are grateful to Deans Michael Schill and Thomas Miles of the University of Chicago Law School for their support of our work, and to Leila Blatt for superb research assistance in preparing the volume. Ginsburg thanks the American Bar Foundation and its director, Ajay Mehrotra. We also thank the participants and commentators in the conference we held in April 2015 on Assessing Constitutional Performance, including Michael Albertus, Nathan Brown, Jose Cheibub, Adam Chilton, Javier Couso, Katalin Dobias, Justin Driver, Amanda Greene, William Hubbard, Alexandra Huneeus, Madhav Khosla, Alison LaCroix, Jennifer Nou, Michael Seidman, Nick Stephanopolous, Geoffrey Stone and Mila Versteeg. Finally, we are grateful to Claire Kim for help in the production process. Their contributions remind us that scholarship, like constitutional performance, is a collective enterprise.