Working nights, weekends and other nonstandard schedules is increasingly common as the United States moves toward a 24-hour-a-day, seven-day-a-week economy, according to the study, which appears in the journal Social Science Research.

Compared with married parents, cohabiting parents -- who live together but are not married -- tend to have lower-paying jobs that may not offer a choice of working a standard 9-5 shift. Cohabiting parents who work nonstandard shifts tend to experience more conflict between work and family life and feel more depressed and less successful as parents and workers than do their peers who work standard shifts, the study argues.

According to the U.S. Census Bureau, the number of cohabiting couples with children has nearly doubled during the past decade, reaching 2.5 million in 2009.

"Cohabiting parents who work these nonstandard shifts certainly warrant more social attention as their numbers continue to grow," said Hui Liu, assistant professor of sociology and lead investigator on the project. "They've already faced economic and social constraints and may be more susceptible to suffering from recent changes in work schedules."

Liu said cohabiting parents are less likely than their married counterparts to take care of their partners' children, pool their income and receive child-care help from family members. These factors make it harder for cohabiting parents who work nonstandard schedules to balance work and family life, she said.

On the other hand, working irregular shifts may actually benefit married couples who share parenting duties by providing an option for one of them to be available for child care during the day.

"This, in turn, may enhance well-being for these married parents," Liu said.

The study analyzed the data of more than 2,300 people in the National Study of the Changing Workforce. The research was supported by the Alfred P. Sloan Foundation for the Center on Parents, Children and Work.

Liu's co-investigators were Barbara Schneider, John A. Hannah Distinguished Professor in the College of Education and professor in the Department of Sociology, and former education graduate students Qiu Wang and Vanessa Keesler.

Liu said future research should focus on the well-being of children of cohabiting and married parents who work nonstandard shifts.

Note: If no author is given, the source is cited instead.

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