Does self-employment increase stress? A co-twin control analysis of Finnish and US twins

Entrepreneurs enjoy autonomy and work on projects they are passionate about, which may improve their mental well-being and reduce stress. At the same time, they face several potential stressors, including long working hours. Empirical evidence on whether those who engage in self-employment experience greater stress than those who do not is mixed, which could reflect the failure to consider self-selection into entrepreneurial careers. In this paper, we re-examine the relationship between self-employment and stress, over and above the self-selection bias of individuals' predispositions, using two separate studies of monozygotic twins. In the first study (monozygotic twins from Finland), stress is reported as a perceptual measure. In the second study (monozygotic twins from the United States), we measure cortisol as a physiological indicator of stress. In both studies, we show a positive association between self-employment and stress (both perceived and physiological) above and beyond the impact of genetic and rearing factors. We also show that long working hours mediate the relationship between self-employment and stress.