Diversity in trade union membership: a typology based on the study of a Spanish trade union

While existing literature on the changing nature of trade union membership concentrates on unidimensional differences between members, this article proposes a multidimensional typology, which considers demographic characteristics as well as labour market position and length of union membership. Our results allow the identification of different member profiles; these are significantly associated to differences in employment conditions, work participation, job satisfaction and union activism. In the last section of the article, we discuss the practical implications that these different member profiles may have for union policy and organisation.