There are a number of possible explanations for this unanticipated result. First, union members may have a higher level of dissatisfaction with the organisation and management processes (Freeman and Medoff, 1984: 21; Bryson et al., 2004), including communications and participative arrangements, and therefore perceive less favourably their degree of influence within the organisation (Kleinman, 2000: 403–404) or the degree of managerial responsiveness (Bryson et al., 2006). Bryson (2004) found that union members had a higher level of job dissatisfaction than non-union workers but that after an extensive array of control variables were included, no significant negative relationship was found. This finding, they suggested, may well be due to a selection bias on the part of employees. Employees who had higher aspirations for their working life may be more likely to join a union. This proposition resonates well in the case of PSR, where some 63.8 per cent of unionised employees indicated that a major reason for joining the union was because they wanted to have a say in matters affecting their working life. Unions themselves may also contribute to this dissatisfaction by raising employee expectations that they are unable to meet (see also discussion on ‘consciousness raising’ in Guest and Conway, 2004: 115–116) and by providing their members with considerable information about problems within the organisation and the problems they are encountering with management. This is likely to be part of the explanation for the findings of this research as at the time of the survey, PSR management were keen to introduce a performance-related pay scheme which had led to an active campaign of opposition by the union.A second explanation is that union members may have higher expectations of voice. Employees join unions for a variety of reasons (Peetz, 1998), but overall, they expect unions to make a difference to their working lives. As Bryson and Freeman (2007: 84) found, ‘unionised workers reported more problems with management’ than non-union workers. In the case of PSR, the major reasons for employees joining the union were a belief in unions, wanting to have a say in things that affect their working life and a belief that unions generate better wages and conditions. Clearly, these union members had high expectations concerning voice. Yet, it was also the case that these expectations were not being met. Improved wages and working conditions were becoming harder to achieve as the enterprise bargaining system, with its emphasis on productivity improvements, had led to trade-offs involving redundancies, a decline in wage relativities with the private sector, and the possibility of a new performance-based pay scheme being introduced.A third explanation is that the overall focus within PSR at the time of the research had shifted from curiosity-led to commercially-driven research with an emphasis on productivity and efficiency. For employees of PSR, most of who were accustomed to the more protected working environment of the public sector, this meant that external factors were now driving research, and the scientific arguments used in the past for justifying research projects were becoming less important. In this environment, the value of union membership was becoming more marginal as union members had less protection than that of the past in the case of redundancies and adverse performance appraisals. In addition, other benefits of union membership such as access to grievance procedures were available to all employees regardless of their union status. It may also have been the case that management's approach to reform, for example the introduction of a performance-based pay scheme that ran counter to the wishes of union members and past practices, may have led many unionists to believe they were being targeted. In this context, the tense state of the relationship between management and the union may have created a negative perception of collective union voice (Freeman and Medoff, 1984).