This book examines how parties voice voter preferences in plenary debates—an often-overlooked dimension of parliamentary politics. Combining theoretical insights with an innovative process model of representation, the book empirically tests how party positions shift between elections and legislative action. Using machine learning to analyse manifestos and speeches, it provides new data and methods for assessing substantive representation. This work will appeal to theorists of representation, comparativists exploring party competition and legislative behaviour, and methodologists employing text-as-data approaches in political research.

Pola Lehmann is a senior researcher at the WZB Berlin Social Science Center, Germany, where she co-leads the internationally renowned Manifesto Project, which holds the world’s most comprehensive collection of election manifestos and party positions. She studied public policy at the Universities of Potsdam and Copenhagen and earned her PhD summa cum laude from Humboldt University of Berlin, receiving the Leibniz Dissertation Award. In 2024, she was a Thomas Mann House Fellow in Los Angeles. She is co-author of Die Ampelkoalition (2022), and her research has appeared in leading journals, including the European Journal of Political Research and Government and Opposition.