in response to changes in employers' needs, labor market conditions, and circumstances in their own lives. Children and teens, like adults, work mainly for the money. Children's income, however, no longer goes primarily toward family support, as it once did: the majority of working adolescents spend most of their incomes on discretionary items or on their individual needs.

The biggest employer of adolescents is the retail sector—restaurants, fast-food outlets, grocery stores, and other retail stores—which employs more than 50 percent of all working 15- to 17-year-olds. The next biggest employer is the service sector (e.g., health care settings such as nursing homes), which accounts for more than 25 percent of working adolescents, followed by 8 percent employed in agriculture. Several of the industries in these sectors of the economy have high rates of injury for all workers.

Some parts of the youth population face unique problems related to work. Children and adolescents who are poor or minority or have disabilities are far less likely than white, middle-class young people to be employed and therefore to reap the potential benefits of work experience. Furthermore, the jobs that poor and minority young people have tend to be in more dangerous industries. When they do work, the hours they work and the wages they receive are comparable to those of other youngsters.

Working has been shown to be associated with both positive and negative consequences for adolescents. Working may increase responsibility, self-esteem, and independence and may help children and adolescents learn valuable work skills. Employment that is limited in intensity (usually defined as 20 hours or less per week) during high school years has been found to promote postsecondary educational attainment. Many studies show positive links between working during high school and subsequent vocational outcomes, including less unemployment, a longer duration of employment after completing schooling, and higher earnings.

However, high-intensity work (usually defined as more than 20 hours per week) is associated with unhealthy and problem behaviors, including substance abuse and minor deviance, insufficient sleep and exercise, and limited time spent with families. Moreover, a high level of work during adolescence has been found to be associated with decreased eventual educational attainment. It should be noted that researchers have often chosen the dividing point of 20 hours of work per week as a convenient way to subdivide hours of work into low-intensity and high-intensity employment; that division is not based on specific research about 20 hours per se.