The mental health cost of long working hours: the case of rural Chinese migrants

Previous studies looking at the effect of long working hours on mental health have been plagued by the high degree of self-selection of those who work long hours. In this paper we use a new survey of rural-to-urban migration in China which uses the fact that migrants are effectively allowed only temporarily in the cities, meaning that those who must return to poorer villages have greater incentives to work long hours than those returning to richer villages. As a result of the temporary nature of migration, the average rural migrant works almost 60 hours per week for 8 years after which they return to their rural home village. Using home village economic indicators as an instrument, we find that working 60+ hours per week increasers our GHQ mental distress index by one standard deviation.