In 2013, 6.8 million workers in the United States held more than one job. Twenty years before, the figure was 7.5 million, although the total number of workers with a job was lower by 15.9 million. The multiple-jobholding rate—the proportion of multiple jobholders among all employed workers—rose from 6.2 percent in 1994 to a high of 6.8 percent during the summer of 1995. It has declined steadily since then and was at 5.0 percent by the end of 2013. Inspection of data from the Current Population Survey (CPS, see accompanying box) reveals that the downward trend holds across various sociodemographic groups of the working-age population (those 16 to 64 years old).
The Current Population Survey: data and definition
The Current Population Survey (CPS) is a monthly survey of households administered by the U.S. Census Bureau under the auspices of the U.S. Bureau of Labor Statistics. The CPS is the source of U.S. official labor market statistics and is thus a firsthand source of information for the purpose of this article.
Since January 1994, CPS respondents have been asked a series of questions that allows the identification of multiple jobholders. A multiple jobholder is defined as an individual who held more than one job during the reference week of the survey and who usually receives a wage or salary from his or her primary job (i.e., the job at which the individual worked the greatest number of hours during the reference week). Excluded from the definition are individuals who were unpaid family workers on their primary job as well as individuals who were self-employed on their primary job and were either self-employed or unpaid family workers on their second job.
CPS respondents are interviewed for 4 consecutive months, are rotated out of the survey for 8 months, and are then included in the survey again for 4 consecutive months. This approach allows researchers to link (a fraction of) CPS respondents across surveys. In so doing, one can compare the labor market position of an individual in 2 consecutive months and identify transitions into and out of multiple jobholding, as is done later in the text of this article.
This article documents the evolution of multiple jobholding from 1994 to 2013 in the United States, shining a light on workers’ transitions into and out of multiple jobholding. These transitions convey information about the propensity of single jobholders to become multiple jobholders and vice versa, trends that in turn help explain why moonlighting has become less common.
Multiple jobholding is relevant to our understanding of the labor market from a variety of perspectives. At the individual level, moonlighting serves both economic and noneconomic purposes, as earlier studies have shown.1 In May 2004, for instance, most workers who were holding more than one job reported doing so in order to earn extra money (38.1 percent), to meet expenses, or to pay off debt (25.6 percent).2 Meanwhile, a nonnegligible fraction of multiple jobholders (17.6 percent) reported that their primary motivation was the enjoyment they received from their second job. Multiple jobholding is also important from a macroeconomic perspective because moonlighting adds millions of jobs to the economy, as the aforementioned figures show. In 1995, for example, when the multiple-jobholding rate was at its highest level, multiple jobholders worked an average of 13.5 hours per week on their second job, thereby adding about a 100 million hours worked to the economy each week.
Figure 1 shows the evolution of the multiple-jobholding rate in the population of working-age individuals.3 As already mentioned, multiple jobholding has been declining throughout almost the entire period examined. Interestingly, earlier studies based on the May supplements of the CPS reported evidence of a rise in multiple jobholding during the 1980s.4 Therefore, the increase between 1994 and 1995 shown in the figure may well have been the continuation of an earlier trend. During the summer of 1995, however, this trend came to an end, and by 2013 the multiple-jobholding rate was at a decadal low. In figure 1 and in subsequent figures, the recession periods shown are those identified by the National Bureau of Economic Research. Previous research has attempted to correlate moonlighting with the different phases of the business cycle.5 For instance, on the one hand, jobs are seen to be more plentiful during economic expansions, a finding that could result in procyclical multiple-jobholding rates. On the other hand, looser credit constraints during expansions could lead to fewer individuals taking on a second job to meet expenses. Perhaps because of these opposing forces, research on the cyclical behavior of multiple jobholding has not reached definite conclusions. The figures in this article confirm the absence of a clear association between moonlighting and the business cycle.
Figure 2 (a through d) depicts the evolution of multiple jobholding within various sociodemographic groups of the working-age population. To provide the reader with the underlying numbers, table 1 further reports decadal averages and average annual changes in the number of multiple jobholders and of multiple jobholding rates, tabulated both in the aggregate and within those groups.
|Demographic category||1994–2003 (average)||2004–2013 (average)|
16 to 24
25 to 54
55 to 64
Less than high school
High school graduate
College or higher
Widowed, divorced, or separated
Note: Levels are reported in thousands; rates are reported in percent. Annual changes are calculated by averaging year-to-year changes over the corresponding period. Levels may not sum to totals because of rounding.
Source: U.S. Bureau of Labor Statistics.
Multiple jobholding has become less common for both men and women, although the downward trend has been more pronounced among men. Multiple-jobholding rates among women held almost steady between the 2001 recession and the 2007–2009 recession. Since then, women’s multiple-jobholding rates have been diminishing slightly. On average over the 2004–2013 period, male and female workers had about the same number of multiple jobholders (3.6 million; see table 1).
Twenty years ago, moonlighting was less common among older workers (ages 55 to 64). However, because multiple-jobholding rates have remained fairly stable among these workers and have declined within the other age groups of the population, the proportion of workers who moonlight became uniform across younger (16 to 24), prime-age (25 to 54), and older workers by the end of the period. Further inspection of data on hours worked shows that prime-age workers are more likely to work full time (at least 35 hours per week) at their primary job and part time at their second job, thus having a longer workweek relative to that of other workers who moonlight.
Multiple-jobholding rates are seen to be more disparate across individuals with different education levels. In line with earlier studies on this topic,6 multiple jobholding increases with educational attainment. Meanwhile, despite the difference in levels, moonlighting has been trending downward within all educational groups. On average over the past decade, multiple jobholding has diminished by 0.6 percentage point every year for both high school graduates and workers with some college education. As a result, the decline has not been less statistically significant among workers who have a lower propensity to moonlight.
Multiple jobholding is less frequent among married and single individuals than among those who are widowed, divorced, or separated. The figures mask some slight differences between men and women. For instance, married men are more likely to moonlight than men who are widowed, divorced, or separated. By contrast, multiple-jobholding rates are higher for single than married women.
In sum, table 1 and figure 2 show that multiple jobholding has become less common within most sociodemographic groups over the past two decades. The downward trend in the aggregate thus does not reflect a compositional change in the working-age population of those groups of workers who were already less likely to moonlight 20 years ago—at least not for the sociodemographic characteristics considered in figure 2.7 Finally, within all subgroups, there is no apparent relationship between multiple jobholding and the business cycle.
Delving further into the findings just described, figure 3 (a through d) shows multiple-jobholding rates separately for workers with a different occupation or industry of employment in their primary job. The occupation or industry of the primary job is relevant for a number of reasons. To begin with, some occupations or industries may entail a work schedule that does not lend itself to holding a second job. Also, different occupations and industries pay different wages, a fact that may affect the need to work at a second job. Finally, to the extent that skills may be specific to the occupation or industry of the primary job, workers may have different opportunities to use these skills or to acquire new skills at a second job.
In line with the preceding discussion, figure 3 shows that there are occupations and industries with either low or high multiple-jobholding rates. Manual workers—for instance, those working in the mining, construction, or manufacturing industry—are less likely to work at a second job. By contrast, a considerable proportion of workers in professional and service occupations hold more than one job. One such example is teachers in elementary, middle, or secondary schools, whose multiple-jobholding rates are no less than 13 percent, as found in earlier studies.8 A relatively more convenient work schedule is probably an explanation for these workers’ high multiple-jobholding rates.
As regards the evolution of multiple jobholding, figure 3 unambiguously shows that changes to the occupation or industry structure of the economy do not explain the downward trend in the aggregate—at least, not for the broad occupation and industry categories presented in the figure. Indeed, multiple jobholding has declined steadily among workers, irrespective of the occupation or industry of their primary job.
From an accounting point of view, the pool of multiple jobholders is a labor market stock: a quantity that can be measured by using a snapshot of the labor market in any given month. A better understanding of its evolution can be gained by looking at labor market flows, which requires following the same workers in 2 consecutive months in order to identify their transitions. In so doing, one can determine whether the downward trend in moonlighting is a consequence of having fewer single jobholders who take on a second job, more multiple jobholders who give up their second job, or a combination of both.
In principle, transitions into and out of multiple jobholding can be measured with respect to many labor market positions of origin and destination: single jobholding, unpaid work, unemployment, inactivity, and more. A closer look at the data reveals that (i) most transitions into and out of multiple jobholding involve single jobholding rather than some other reason, (ii) among single jobholders, part-time and full-time workers have markedly different propensities to take on or to give up a second job, and (iii) transitions between multiple jobholding and either unemployment, inactivity, or unpaid work are quantitatively negligible. Altogether, these observations suggest that transitions into and out of multiple jobholding (M) ought to be measured with respect to full-time single jobholding (F), part-time single jobholding (P), and nonemployment (N), where the latter category effectively lumps together all working-age individuals who are either unpaid family workers, unemployed, or out of the labor force.
Figure 4 (a through l) shows monthly transition rates into multiple jobholding within the various sociodemographic groups of the working-age population. Figures 4a, 4d, 4g, and 4j display the proportion of full-time single jobholders who become multiple jobholders the next month (F à M); figures 4b, 4e, 4h, and 4k show the proportion of part-time single jobholders who become multiple jobholders the next month (P à M); and figures 4e, 4f, 4i, and 4l depict the proportion of nonemployed individuals who become multiple jobholders the next month (N à M). The picture that emerges is that individuals of working age have become less likely to move into multiple jobholding during the past decades, irrespective of their sociodemographic characteristics. That is, all transition rates into multiple jobholding exhibit a downward trend.