Involuntary Non-Regular Workers in Japan and Their Mental Health (Japanese)

Using Japanese longitudinal data from the Keio Household Panel Survey 2004-2010, this paper focuses on those who work involuntarily as non-regular workers because they could not secure jobs as regular employees. Our findings are as follows: First, the majority of non-regular workers are categorized as voluntary although the number of involuntary non-regular workers is not negligible—about 1.5 times more than that of the unemployed. Second, more involuntary non-regular workers are found among non-married workers, those in their 20s or 40-50s, contract and temporary agency workers, transport and machine-operation workers, or manufacturing process workers. Third, judging from the selection and transition behavior among labor force status, involuntary non-regular workers have more similarity with unemployed persons and less similarity with voluntary non-regular workers. Fourth, the measured mental health index indicates that the stress levels of non-regular workers, unemployed persons, and non-workers are higher than that of regular employees. After controlling for individual heterogeneity and endogeneity of the labor force status, however, only involuntary non-regular workers and unemployed persons show to have higher stress levels than regular employees. It is interpreted that involuntary non-regular workers as well as unemployed persons are worse off due to the demand-side constraints, and they are therefore likely to face mental health illness compared with regular employees or voluntary non-regular workers.