PATRICK SEYD is Professor of Politics and Director of the Institute for the Study of Political Parties at the University of Sheffield. He is author of The Rise and Fall of the Labour Left, co-author with Paul Whiteley and Jon Parry of Labour and Conservative Party Members, 1990-92, and co-author with Paul Whiteley of Labour's Grass Roots: The Politics of Party Membership. PAUL WHITELEY is Professor of Politics at the University of Essex. He is the author of The Labour Party Crisis, Models of Political Economy, and is co-author with Patrick Seyd and Jon Parry of Labour and Conservative Party Members, 1990-02, and co-author with Patrick Seyd of Labour's Grass Roots: The Politics of Party Membership. He received the Political Science Communication Award by the Political Studies Association in 2003.