Upjohn Institute Working Paper No. 95-40

**Published Version**

Industrial Relations 40 (January 2001): 89-120




Multiple job-holding is a significant characteristic of the labor market, with approximately 6 percent of all employed males reporting a second job in 1993 (Mishel and Bernstein, 1995, p. 226). Moonlighting reflects growing financial stress arising from declining earnings, as well as an increased need for flexibility to combine work and family. Approximately 40 percent of moonlighters report taking the second job due to economic hardship. Additionally, moonlighting is a reflection of the worker's choice to pursue entrepreneurial activities while maintaining the financial stability offered by the primary job. To restate in economic terminology, moonlighting arises from at least two distinct reasons. First, many individuals hold multiple jobs due to some sort of constraint on the primary job that limits that job's earnings capacity. Second, moonlighting may arise because the labor supplied to the two jobs are not perfect substitutes. That is, the wage paid and utility lost from the forgone leisure may not completely reflect the benefits and costs to working. For example, working on the primary job may provide the worker with the credentials to acquire a higher paying second job, such as a university psychologist testifying in a jury trial. Or, working on the second job may provide some satisfaction not received in the same amount or manner from the primary job, such as a comedian who has a "regular" job by day and performs at night. In either example, the costs and benefits of both jobs are more complex than the monetary wages paid and the forgone value of leisure. When faced with such nonpecuniary benefits and costs, optimizing behavior may lead a worker to take two jobs. In contrast to workers who moonlight because they are constrained on their primary jobs (PJ), we expect these kinds of moonlighters to moonlight for longer periods of time because optimizing behavior leads them to supply labor to more than one job, even in the long run. We might also expect to see smaller wage differences between jobs for such workers and the second job (SJ) wage could even be higher than the primary job wage in some situations.

Issue Date


Subject Areas

LABOR MARKET ISSUES; Job security and unemployment dynamics; Nonstandard work arrangements


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Kimmel, Jean, and Karen Smith Conway. 1995. "Who Moonlights and Why? Evidence from the SIPP." Upjohn Institute Working Paper No. 95-40. Kalamazoo, MI: W.E. Upjohn Institute for Employment Research.