The Development of Trade Unions in Western Europe: Global Convergence or Cross-national Di-

versity? Trade unions play an important role in Western Europe. They have been subject to, and agents of, social and political changes that reshaped the post-war industrial society. In recent years, trade unions have been facing the threat of membership decline and the challenges of global competition and European economic integration. This poses the question whether un-ion movements are under pressure to adapt in a similar way or whether they differ in their responses. Do we find a trend towards global conver-gence or does cross-national diversity persist among union movements in Western Europe? Drawing on comparative data from an international re-search project, we will provide a short portrait of the main patterns in un-ion density and organisational concentration. Instead of a general trend toward convergence, we find signs of persisting diversity across Western Europe in union responses to both social changes and global challenges. Union Development in Compariso