Do Temporary Workers Always Lower Workgroup Effectiveness? The Moderating Effect of Job Similarity in Blended Workgroups

Workgroups containing both permanent and temporary workers are often referred to as being ‘blended’. There exists a general view in the literature that workgroups blended in this way function less well with greater rather than fewer temporary workers. However, this notion has received little direct testing. Drawing on social identity theory and the input-process-output model of group effectiveness, this study examines the performance of 131 workgroups containing varying proportions of temporary agency workers, along with the proposed group processes: distributive justice climates reported by permanent and temporary workers and altruistic behaviors from permanent to temporary workers and vice versa. We find that blended workgroups with a greater proportion of temporary workers do not exhibit poorer justice climates, altruism, or performance; the hypothesized negative effects only emerge when jobs performed by temporary and permanent workers within the workgroup are highly similar. Counter to expectations, a positive indirect effect between proportion of temporary workers to workgroup performance via altruism from permanent to temporary workers was found when job similarity is low. Theoretical and practical implications are considered, focusing on the importance of managing social identity threat in blended workgroups.