For some workers, one job isn’t enough. In any week, more than 5 percent of workers hold more than one job (about 7.2 million people in October 2012). While most multiple jobholders work only two jobs, a significant share, about 10 percent, work three or four jobs.
Why do workers hold multiple jobs? The reasons are varied. One explanation is that workers may use multiple part-time jobs as a substitute for one full-time job. This is evident in the data. Part-time workers are more than twice as likely to work a second job as full-time workers. Yet still more than 4 percent of full-time workers hold multiple jobs.
Another explanation for working multiple jobs is that a worker’s main job provides income and their second job gives them an opportunity to do something they enjoy. In 2004, the most recent year in which multiple jobholders were surveyed on the reasons for taking extra work, almost 20 percent reported that they did so because they enjoyed the work done on their second job.
However, in this same survey, the primary reason most workers held multiple jobs was to supplement their income from their main job. Almost two-thirds of workers identified wanting to earn extra money or needing the additional income to meet current expenses as the primary reason for working more than one job.
The incidence of moonlighting shows important patterns across demographic groups. It has been well documented that females are more likely than males to hold multiple jobs. Perhaps less well known is that the rate of multiple job holding varies significantly by education level. Those with some college or a college degree are almost twice as likely to hold multiple jobs as those with just a high school degree.
It is unclear whether these differences are driven by differences in workers’ preferences or by other labor market factors. One important factor in the decision to moonlight may be the type of work performed, or occupation, on the main job. This may be due to the fact that some occupations offer fewer hours to workers or have irregular work schedules, which may make moonlighting more necessary or amenable.
Unsurprisingly, the decision to moonlight is highly related to occupation on the main job. Moonlighting is strongest for education occupations, where the rate is 12 percent for males and 8 percent for females. Likewise, 10 percent of males in protective service occupations choose to take on an extra job. By contrast, fewer than three percent of males working in construction occupations work multiple jobs.
Looking at the incidence of moonlighting by occupation reveals one of the main reasons for the aggregate gender difference of multiple job holding. In education, where the rate of moonlighting is highest, females outnumber males three to one. So while the aggregate difference leads people to believe that females moonlight at a higher rate than males, the truth is that people in education moonlight more than other occupations and females are more likely to be in education. Males are actually more likely to moonlight in this occupation and in most other occupations.
While occupation can explain much of the difference in moonlighting by gender, it does very little to explain the differences by education. For most occupations, even restricting the analysis to only male workers who are working full-time on their main job, those with some college or higher are significantly more likely to work multiple jobs than those with a high school degree or below. This is even true for occupations that are heavily dominated by high school graduates, like construction, maintenance, production, and transportation occupations. One explanation for this disparity may be that individuals who choose to attain higher levels of education have above-average motivation and are likewise highly motivated to work additional jobs in the labor market.
Finally, unlike many other features of the labor market, for example unemployment and hours worked, the rate of multiple job holding has changed very little over the last 10 years. While the unemployment rate has close to doubled during the recent economic downturn, the overall incidence of moonlighting has changed only about 15 percent from a pre-recession high of 5.78 percent in 2004 to its current low in 2012 of five percent.
The relationship between recessions and multiple job holding is not well established. On the one hand, workers may be more willing to take on additional jobs as they experience falling incomes. At the same time, demand for workers from firms may be falling as well. The effects of these two forces may offset each other, producing little change in the overall rate. Alternatively, recessions may have only a minor effect on multiple job holding because many of these workers hold these jobs not for monetary reasons but to do something they enjoy. Finally, balancing multiple jobs is a difficult task. Another explanation may be that even the most challenging economic times cannot keep these highly motivated workers out of the labor market.