This study addresses a question that, despite its apparent simplicity, has yet to be satisfactorily answered by social scientists: Does holding a job while enrolled in high school enhance, detract from, or have no effect on subsequent career outcomes? From a theoretical perspective, high school employment has an ambiguous effect on career outcomes. On one hand, it may give students a "leg up" in their subsequent careers by providing them with marketable skills, good work habits, and knowledge of the world of work. On the other hand, high school employment may indirectly hinder subsequent employment opportunities by preventing students from performing as well in high school as they otherwise would. In light of the widely documented difficulties faced by many youths in transiting from school to a permanent, productive position in the labor force, it is important to know which effect dominates. After all, public policy can readily be directed toward helping high school students gain employment (by providing job placement services, for example) or, as appropriate, toward discouraging such activities.
The reason social scientists have failed to reach a consensus on the role of high school employment is because it is extremely difficult empirically to identify the net effect of high school work experience on measures of subsequent career outcomes such as wages, earnings, weeks worked, or weeks unemployed. Consider a situation where 24-year old workers who held jobs while in high school are found to earn higher hourly wages, on average, than similarly aged workers who did not hold jobs in high school. Before concluding that high school employment enhances subsequent labor market productivity, one must acknowledge that the two "types" of workers may differ in many dimensions besides high school employment status. There may be significant differences in their family backgrounds, the quality of their high schools (and the intensity of their school effort), their levels of post-secondary education, the amount of post-school work experience they gained, and even their innate ability. Unless each of these factors is "held constant," we cannot tell whether high school employment has a direct, skill-enhancing effect on subsequent wages or whether one or more of these factors explains the observed difference in average wages. Moreover, a simple comparison of average wages earned at a point in time cannot reveal whether the relationship between high school employment and subsequent wages changes over time.
The current study focuses exclusively on the relationship between high school employment and subsequent average hourly wages rather than considering a broad array of career outcomes. However, it contends with the complexity of this single relationship in ways that previous research does not.