The study focuses on the relationship between job insecurity and self-reported job performance. Based on theoretical, empirical, and statistical arguments, we propose that this relationship is U-shaped and mediated by vigour at work. This assumption was tested cross-sectionally and across two measurement points, and against two alternative explanations, namely that the U-shaped relationship might be due to the influence of the moderators optimism and supervisory support. The findings of a study among a large group of job-insecure employees of two Finish universities (n = 2,095) confirm the U-shaped effect of job insecurity on self-reported job performance. This effect was shown to be robust against the moderating influence of optimism and supervisory support and was partially explained by decreased vigour. The inclusion of a second data wave indicated that job insecurity predicted job performance 1 year later also in a U-shaped form (n = 1,289). Overall, the results suggest that taking quadratic effects into account adds to the understanding of the relationship between job insecurity and self-reported job performance.
- The study reveals that the relationship between job insecurity, vigour, and self-reported performance is slightly U-shaped.
- At lower to moderate degrees of intensity, job insecurity is negatively related to self-reported job performance, whereas at higher degrees, the effect is less negative.
- The U-shaped effect can partly be explained by vigour: at low and high degrees of job insecurity, vigour is slightly less impaired than at moderate degrees. The study does not indicate that job insecurity is a motivator in the workplace.