This paper tracks the rise in the percentage of employees who have never become union members (¿nevermembers¿) since the early 1980s and shows that it is the reduced likelihood of ever becoming a member rather than the haemorrhaging of existing members which is behind the decline in overall union membership in Britain. We estimate the determinants of ¿never-membership¿ and consider how much of the rise can be explained by structural change in the labour market and how much by change in preferences among employees. We find a similar trend in the unionised sector, indicating that the rise in never-membership for the economy as a whole is not linked solely to a decline in the number of recognised workplaces.