<p>Industrial Relations Journal, Vol.&nbsp;43 no. 6 (Nov 2012), p. 527-547</p> <p>Available in the library. See journal shelves.</p> <p>Available online.&nbsp;</p>

Union mergers have been widely studied in a variety of countries; however, little is known about their impact on union effectiveness. This article draws on in-depth interviews with officials and works councillors from four German unions, as well as on a representative survey of German works councils, to analyse how a union's merger status shapes its effectiveness in three spheres of activity: political lobbying, collective bargaining and establishment-level interest representation. We compare two cases of merger with two cases of continued organisational independence, finding that merger outcomes for individual unions vary considerably across our three union functions.