Child Trends reports:
As of 2013, more than one in four children (26 percent) did not have at least one resident parent employed full-time, year-round. Among children younger than six, three in ten (30 percent) were without secure parental employment and, of children in families headed by single mothers, more than half (58 percent).
Secure attachment to the labor force, defined here as full-time, full-year employment, is a major contributor to financial stability and well-being for families. For low-income families, it is not a guarantee of escape from poverty,  but it is associated with higher family income and greater access to private health insurance. Higher income, in turn, is associated with many positive child outcomes including better health, behavior, academic achievement, and financial well-being as adults., In particular, deep, persistent, and early poverty are related to poorer child development. A study of low-income families found benefits to children’s social-emotional skills when their mothers were employed early in the child’s life, compared with similar children whose mothers who were not employed. However, in some cases, long hours of employment among mothers with very young children have been associated with modestly negative child outcomes. Studies have found drops in family income, as well as income fluctuation, to be associated with a greater risk of behavioral problems, and lower reading and mathematics achievement, compared with children in families who had not been poor. More recent research links parental (particularly fathers’) permanent job loss to increased likelihood of parental divorce, family relocation, and children’s repeating a grade; and to decreased earnings when children enter the labor force. Thus, the “scarring” effects of parental unemployment may be multigenerational.