Characteristics of Low-Wage Workers and Their Labor Market Experiences: Evidence from the Mid- to Late 1990s. Spell Information


The sample contains a large number of low-wage job spells (Table VI.1). The larger number of spells for females than males (10,259 spells for 5,985 female workers, compared to 6,373 spells for 3,934 male workers) is consistent with our earlier findings that low-wage workers are disproportionately female. About 20 percent of spells are right-censored, and nearly 30 percent are left-censored. Few are both right- and left-censored. Because of duration dependence, mean observed spell durations are considerably longer for left-censored spells than for non-left-censored ones.(47)

Table VI.1.
Job And Employment Spell Information For Workers Starting Low-Wage Jobs, By Gender
  Spell Type for Males Spell Type for Females
Job Employment Job Employment
Low-Wage Spells
Total Number of Spells 6,373 4,882 10,259 7,755
Number of Spells per Worker (Percentages)
   1 62 75 58 73
   2 22 18 23 20
   3 or more 16 7 19 7
   (Average number) (1.7) (1.3) (1.8) (1.4)
Percentage of Spells That Are:
   Right-censored 18 22 20 25
   Left-censored 29 38 28 36
   Right- and left-censored 4 6 3 6
Mean Observed Spell Duration (Months)(a)
    Non-left-censored spells 7 8 8 10
   All spells 25 31 25 32
Percentage of Low-Wage Spells with Exit Type(b)
   Another low-wage job 18 NA 21 NA
   Medium- or high-wage job 32   22  
      In the same job 21   15  
      In a different job 11   7  
   Unemployment 14   10  
   Not in the labor force 13   21  
Spells of Any Wage Type
Total Number of Spells 6,170 3,943 10,057 6,832
Number of Spells per Worker (Percentages)
   1 61 77 58 74
   2 22 16 23 19
   3 or more 17 7 19 7
   (Average number) (1.7) (1.3) (1.8) (1.3)
Percentage of Spells That Are:
   Right-censored 32 53 32 48
   Left-censored 28 42 27 39
   Right- and left-censored 10 27 9 21
Mean Observed Spell Duration (Months)(a)
   Non-left-censored spells 10 13 10 13
   All spells 29 60 28 41
Source: 1996 SIPP longitudinal files for those in low-wage jobs.
Note: All figures are unweighted. A job spell of any wage type pertains to the period that the worker was employed with the initial employer, while the employment spell of any wage type includes continuous changes from one job to another. Low-wage job spell pertains to the duration with the initial employer, in which the worker continues to receive low pay, and the low-wage employment spell includes continuous changes from one low-wage job spell to another. The definitions for each spell type are given in Section A.1.
a. Figures pertain to the mean spell length observed during the panel period, including spells that are still in progress at the end of the period (that is, right censored spells). Thus, the figures are shorter than the ultimate mean lengths of the spells.
b. Figures pertain to exit types for non-left-censored spells only.
NA: = Not applicable

The analysis file contains multiple low-wage job spells for a substantial number of workers (Table VI.1). On average, male and female workers each contributed about 1.8 spells to the file, and about 40 percent contributed at least 2 spells. These results are consistent with our findings from the overall employment analysis that many low-wage workers exit low-wage jobs, but many return to the low-wage labor market.

Exit types vary across low-wage workers (Table VI.1). The most common exit type for both male and female low-wage workers in our sample was into higher-paying jobs. Among non-right-censored spells, about 32 percent of spells for males and 22 percent of spells for females ended in this way. Furthermore, most of these spells ended in a higher-wage job with the same employer rather than with a different employer. At the same time, however, many workers exited their low-wage jobs into another low wage job (20 percent of spells for males and females) or into nonemployment.

Interestingly, spell information for low-wage job and low-wage employment spells are similar (Table VI.1). This occurs because only a relatively small percentage of workers moved directly from one low-wage job to another.

The sample contains fewer job and employment spells than low-wage job and employment spells (Table VI.1). This occurs because many low-wage job spells resulted in continued employment in higher-wage jobs. Stated differently, only a relatively small fraction of low-wage spells ended in nonemployment. Thus, mean observed spell durations are somewhat longer for the overall job and employment spells than for the low-wage spells. Similarly, a much higher percentage of overall job and employment spells are right-censored.

Finally, the analysis files contain more medium-wage than low-wage job and employment spells for both males and females (Tables E.1 and E.2). We expected these findings because our cross-sectional analysis found that the medium-wage sector is the largest labor market sector, and because our overall employment analysis found that many low-wage workers obtain medium-wage jobs. Not surprisingly, observed mean spell durations are shorter for low-wage than higher-wage job and employment spells.

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