Compensation and Working Conditions Summer 2000 27

Part-time Workers' Earnings

JEROME E. KING

Part-time Workers’

Earnings:

Some Comparisons

For the first time, national data on employment, average

hours worked, and average hourly earnings for part-time

workers are available from the National Compensation

Survey. This presents an opportunity to make comparisons with full-time workers. This article makes those

comparisons. In addition, it estimates the effects of the

concentration and density of part-time workers on their

earnings, and highlights occupations in which part-time

workers earn higher average hourly wage rates than do

their full-time counterparts.

Jerome E. King is an economist in the Division of

Compensation Data Analysis and Planning,

Bureau of Labor Statistics.

Telephone: (202) 691-6209

E-mail: King_J@bls.gov

Full-time workers generally earn

higher average hourly pay than

part-time workers. New data

from the 1997 National Compensation

Survey (NCS) show that economywide earnings for full-time workers averaged $15.77 versus $8.89 per hour

for part-time workers.1 This pattern

held for law teachers, where average

hourly earnings for full-time workers

($58.67) exceeded those of their parttime counterparts ($20.65); for physicians, however, the inequality was reversed, with part timers averaging

$56.57, compared with $37.49 for full

timers. The variation by occupation

in the relationship between full- and

part-time average hourly earnings presents a challenge for researchers.

What factors account for this variation? Is this relationship somewhat

constant by occupational group, industry, or area?

Since its inception, the NCS has

provided data on part-time workers’

average hourly earnings for selected

localities.2 These data are reported for

selected occupations and occupational

levels, and for occupational groups and

group levels.3 As part of the NCS

phased implementation, the first data

covering part-time workers in the entire United States were published in

September 1999.4 These data provide

an opportunity to examine the characteristics of average earnings and

average hours worked by part-time

workers on a national basis. They provide a snapshot of the contrasts between full- and part-time average earnings. Future NCS data will present

the opportunity for descriptive trend

analysis of part-time average earnings.

Sector and area

The NCS divides surveyed workers

into two sectors: (1) Private industry;

and, (2) State and local government.

Table 1 shows the percent of part-time

workers by sector and area.5 In addi-
28 Compensation and Working Conditions Summer 2000

tion, part-time average hourly earnings

and average weekly hours worked are

presented as percentages of their fulltime counterparts.

Notice the contrasts between the

two sectors. Part-time workers made

up 14 percent of State and local government employment, compared with

19 percent of private industry workers. The average hourly earnings for

part-time State and local government

workers, at 67 percent of full-time

State and local government workers’

average earnings, were higher than

those of their private industry counterparts (55 percent). The ratio of average weekly hours worked for parttime private industry workers exceeded

those of their State and local counterparts, 54 to 49 percent, respectively.

However, one should use caution with

comparisons because of dissimilarities

in the occupational composition of the

two sectors. For example, professional

specialty and technical workers, who

tend to have higher average earnings,

made up a larger percentage (39 percent) of State and local government

workers than of private industry workers (15 percent). (Table 2 contains additional information on occupational

composition.)

Table 1 also breaks out workers by

metropolitan and nonmetropolitan

area.6 One of the similarities between

metropolitan and nonmetropolitan areas is in the ratio of part-time workers’ average weekly hours to those of

their full-time counterparts. The percentages were virtually identical, 53

percent and 52 percent. In contrast,

part-time nonmetropolitan workers

earned more, as a percentage of their

full-time counterparts’ average hourly

earnings, than did part-time metropolitan workers.7 The conventional

perception is that metropolitan workers fare better than nonmetropolitan

workers due to better job opportunities and greater bargaining power. The

fact that this does not hold true for

metropolitan part-time workers is a

finding that invites further research.

Finally, the percent of nonmetropolitan

workers who were part time was 4 percentage points less than that of their

metropolitan counterparts. Coincidentally, the sector and area ratios of

part-time to full-time average hourly

earnings were identical, 67 percent

and 55 percent. Again, due to dissimilarities in occupational composition, caution must be used when making comparisons.

Part-time worker concentration

Table 2 shows the distribution of parttime workers across occupational

groups. More than 4 out of 5 parttime workers were in private industry.

This closely reflects the distribution of

all workers between these two sectors.

(See table 1.) The four occupational

groups that accounted for more than

half (57 percent) of all part-time workers were sales; administrative support,

including clerical; food service; and

handlers, equipment cleaners, helpers,

and laborers. These occupational

groups typically have jobs with relatively low skill requirements and earnings. By contrast, most professional

specialty; executive, administrative,

and managerial; and blue-collar occupations (which typically have jobs with

relatively high skill requirements and

earnings) have low estimated counts

of part-time workers.

There also were noteworthy contrasts in occupational composition between the sectors. Teachers, except

college and university, comprised 15.5

percent of the part-time workforce for

State and local government compared

with 1 percent in private industry. In

private industry, 19 percent of parttime workers were sales workers, an

occupation rarely found in State and

local governments.

Part-time worker density

Whereas table 2 shows the distribution of part-time workers across occupational groups, table 3 shows the

prevalence of part-time jobs within

occupational groups. For example,

almost half of the workers within the

food service and personal service occupations worked part time. For sales

workers, the ratio was nearly 4 out of

10; for health related workers, nearly 3

out of 10; and for college and university teachers, 1 out of 4.8

There are many occupational

groups that exhibit a strong contrast

in part-time densities between private

industry and State and local government. The results are mixed rather

than consistent. In general, however,

private industry occupations exhibited

higher densities of part-time workers

than did State and local government

occupations. The following are occupational groups in which private industry had the higher density of parttime workers:

• Health related

• Teachers, except college and university

• Social scientists and urban planners

• Handlers, equipment cleaners,

helpers, and laborers

• Protective service

• Health service

• Cleaning and building service

The following are occupational

groups in which State and local government exhibited a greater density of

part-time workers:

• Writers, authors, entertainers,

athletes, and professionals, n.e.c. 9

• Transportation and material

moving

• Personal service

Rating part-time jobs

Chris Tilly, a professor of economics

at the University of Massachusetts,

places part-time jobs into three categories.10 “Short time” part-time jobs are

demand driven and most prevalent in

goods-producing industries, such as

manufacturing, construction, and mining. “Secondary” part-time jobs are

those with the characteristics of low

pay and skill requirements, undesirable schedules, and high turnover.

“Retention” part-time jobs are those

with high pay and skills requirements,

and greater advancement opportunities. Do NCS data support Tilly’s

claim of contrasting earnings’ char-
 Compensation and Working Conditions Summer 2000 29

Part-time Workers' Earnings

acteristics between secondary and retention part-time jobs?

Because a high wage is one of the

basic characteristics of retention parttime jobs, retention part-time jobs are

more likely to be found as average occupational earnings increase. As

wages increase, it is reasonable to expect the earnings differential between

part- and full-time workers to decrease

because of the worker’s additional bargaining power due to increased skills

and training. In a simple compensating wage differential model, wages and

benefits substitute for each other.11 If

this substitution effect is operative,

retention part-time wages could even

exceed full-time wages within the

same occupation.

To examine these possibilities, NCS

national wage and employment data

were used to create three variables for

analysis. The first is a simple ratio of

part-time average hourly earnings to

full-time average hourly earnings

(hereafter referred to as the earnings

ratio) for a given NCS occupation.12

For each occupation, density and concentration variables also were created.13 The density variable reflects

the percent of workers in an occupation who are part-time. The concentration variable reflects the percent of

all part-time workers who are within

a given occupation.

Out of the initial 446 survey occupations, some did not have data or had

data that did not meet publication criteria for both full- and part-time average hourly earnings. Because an earnings ratio could not be calculated, these

occupations were dropped from the

data set. The final data set consisted

of 211 occupations.

For the earnings ratio, the mean

(0.81) and the median (0.80) were virtually identical. The maximum was

1.73 (legislators) and the minimum

was 0.34 (athletes). The standard deviation was 0.21. These simple statistics reflect unweighted data because

each occupation represents widely

varying percentages of total employment. Sorting by band widths of onetenth, chart 1 displays the frequency

of these earnings ratios in a pattern

that closely resembles a normal distribution.

It would be useful to know if there

is a relationship between the pattern

of earnings ratios and full-time average hourly earnings. Do higher-wage

jobs have higher earnings ratios? Do

lower-wage jobs have lower earnings

ratios? A correlation measure was

taken between full-time average hourly

earnings and earnings ratios.14 A correlation coefficient of -0.016 was calculated, providing no evidence of a

relationship between the level of fulltime average hourly earnings and the

earnings ratio. To determine if such a

relationship exists only for higherwage jobs, all occupations with a fulltime average wage below $15 per hour

were removed from the data set.15 The

resulting scatterplot of the full-time average hourly earnings and the earnings ratio for occupations with a fulltime wage above $15 per hour visually

reinforces the lack of evidence for the

existence of retention part-time jobs.

This assumes that high earnings ratios are an indicator of retention parttime jobs. (See chart 2.)

In contrast, with a correlation coefficient of 0.82, part- and full-time

average hourly earnings were found to

have a strong relationship by occupation. In a simple least squares regression16 of part-time average hourly

earnings on full-time average hourly

earnings, the estimated coefficient for

full-time earnings was 0.78, with a

standard error of 0.03724 at a 99+

percent level of confidence. When the

data set was restricted to full-time average hourly earnings greater than or

equal to $15 per hour, the estimated

coefficient changed to 0.61 and the

standard error increased to 0.09378,

with the level of confidence remaining at a 99+ percent level. Chart 3

displays another scatterplot of the relationship between these two variables.

Note the deterioration of a linear relationship when the full-time wage exceeds $15 per hour.

Another model regresses, by least

squares, part-time average hourly

earnings on full-time average hourly

earnings, density, and concentration,

by occupation. While acknowledging

that such a model is underspecified, it

is still interesting to see its results.17

Table 4 shows the estimated coefficients for all jobs and for higher-wage

jobs, and confirms the significance of

full-time average hourly earnings on

part-time average hourly earnings.

Density was significant only for

higher-wage jobs and concentration

was insignificant for both job sets.

Charts 4 and 5 are scatterplots of part0

10

20

30

40

50

60

0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7

 NOTE: 211 observations were unsed xx occupations and xx occupational groups.

CHART 1. Histogram of the ratio of part-time average hourly earnings to full-time

average hourly earnings by occupation, National Compensation Survey, 1997

Number of occupations

Earnings ratio
30 Compensation and Working Conditions Summer 2000

time wages to density and concentration, respectively. They visually

complement the information in table 4.

There is a marked difference in correlation between the earnings ratio and

the part- and full-time average hourly

earnings. (See table 5.) While the fulltime wage has negligible correlation

for both sets of occupations, the parttime wage has a strong positive correlation for both all jobs and higherwage jobs. At 0.82 and 0.61, the

strength of the relationship between

the part- and full-time average hourly

wage is confirmed.

When comparing all jobs to higherwage jobs, of the nine correlation coefficients calculated, three weak, negative correlations became negligible;

two negligible and two positive correlations stayed the same. The relationship between density and the earnings

ratio changed from negligible to

weakly negative; and the density and

full-time average earnings relationship

shifted from weakly negative to weakly

positive. Because most of the correlation coefficients are weak, it is difficult to make any conclusive comparisons. What can be stated is that, as

the full-time average wage increased,

the part-time average wage and the

earnings ratio became less predictable.

Part-time earnings and health

field occupations

Estimated part-time employee counts

were summed for all occupations in

which average part-time earnings exceeded average full-time earnings.18

This total was computed as a percentage of the total number of parttime workers. An estimated 18 percent of the total sampled workforce

was part time; 10 percent of these

part-time workers (approximately 2

percent of the total sampled

workforce) were in occupations in

which the part-time average hourly

earnings exceeded those of their

full-time counterparts.

There were 26 occupations for

which the ratio of average part-time

to average full-time earnings was

greater than 1. White-collar occupations dominated, with 24 of the 26, and

service occupations had the remaining 2. Interestingly, no blue-collar

occupation had an earnings ratio

greater than 1.

Of the 26 occupations with an earnings ratio greater than 1, 14 were

white-collar occupations related to the

health field.19 Table 6 shows selected

characteristics of these 14 occupations.

Twenty-nine percent of all health related workers were part-time and, of

these part-time workers, only 7 percent had lower average hourly earnings than their full-time counterparts.

Among technical workers, 4 of the 5

occupations with earnings ratios

greater than 1 also were in the health

field, reinforcing the association between health field part-time jobs and

higher earnings.

The highest earnings ratio was for

physicians (1.51), followed by medical science teachers (1.29), dietitians

(1.22), and speech therapists (1.21).

It appears that the skill requirements

and training associated with a particular job determined the degree to which

part-time average hourly earnings exceeded full-time average hourly earnings. For example, the technical and

service occupations tended to have

lower earnings ratios. Does greater

labor market power explain the ability of part-time health field workers

to command higher earnings relative

to their full-time counterparts? Or is

it the special demands of healthcare

work schedules?20 This is another

0

10

20

30

40

50

60

0 10 20 30 40 50 60 70

Full-time wage (dollars)

CHART 3. Average full-time hourly earnings as a predictor of average part-time

hourly earnings by occupation, National Compensation Survey, 1997

 Part-time average hourly earnings (dollars)

Full-time average hourly earnings (dollars)

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 10 20 30 40 50 60 70

Full-time wage (dollars)

Earnings ratio

CHART 2. Ratio of part-time to full-time average earnings and average full-time

earnings greater than or equal to $15 per hour by occupation, National

Compensation Survey, 1997

Full-time average hourly earnings (dollars)

NOTE: Each point represents an occupation.

NOTE: Each point represents an occupation.
 Compensation and Working Conditions Summer 2000 31

Part-time Workers' Earnings

0

10

20

30

40

50

60

012345

Concentration (percent of all part-time workers by occupation)

area that deserves further research.

Compensation costs

It is widely recognized in the literature that part-time workers have lower

access to, and participation in, benefits.21 The Bureau’s 1997 Employee

Benefits Survey data reveal that 76

percent of full-time employees participated in medical care programs, as

opposed to 21 percent of part-time

employees.22 For retirement programs, this same survey shows another

strong contrast: 79 percent of full-time

employees participated in a retirement

program, compared with 34 percent of

part-time employees. Employer Costs

for Employee Compensation (ECEC)

data show how employer costs for benefits vary by occupational and industry groups, and by part- and full-time

status.23 For private industry workers, table 7 shows the ratios of part- to

full-time workers for total compensation, wages and salaries, total benefits,

and selected individual benefit costs

per hour worked. Many of these values confirm the findings of an earlier

study at the Bureau of Labor Statistics

that used data from the ECEC to look

at how compensation costs per hour

worked varied for part-time workers

when compared to those of full-time

workers.24

In private industry, part-time workers received 47 percent of the total

compensation of full-time workers.

Wages and salaries of part-time workers were 54 percent of their full-time

counterparts’ earnings. Benefits,

therefore, made up a smaller proportion of part-time workers’ compensation—19 percent, as compared to 28

percent. Sales workers had the lowest

ratios in total compensation, wages

and salaries, total benefits, supplemental pay, and legally required benefits.

Administrative support, including

clerical workers fared better than other

occupational groups, with the highest

ratios in total compensation, wages

and salaries, paid leave, supplemental pay, legally required benefits, and

total benefits. Blue-collar workers had

the highest ratio for insurance, while

workers in retail trade had the highest

ratio for retirement and savings.

Workers in goods-producing industries

had the lowest ratios in paid leave and

retirement and savings, while workers in service occupations had the lowest insurance ratio. Overall, for all

categories, the ratios for costs of legally required benefits were closest to

one. The lack of employer discretion

in granting access to these benefits to

these benefits helps explain these ratios. In addition, higher-paid full-time

workers are more likely to reach the

earnings ceilings that are placed on

several of these benefits: this tends to

increase these cost ratios. Table 8

shows the differences in employer

costs per hour worked for part- and

full-time workers.

Summary

There are marked compositional differences by occupation between private

industry and State and local government. These differences must be

weighed when comparing aggregate

average hourly earnings. Part-time

density and concentration character0

10

20

30

40

50

60

0 20 40 60 80 100

Density (percent of workers who are part time by occupation)

CHART 4. Average part-time hourly earnings as a function of part-time worker

density1 by occupation, National Compensation Survey, 1997

Part-time average hourly earnings (dollars)

1 Density is the percent of workers within a given occupation that are part-time.

NOTE: Each point represents an occupation.

 1 Concentration is the percent of all part-time workers within a given occupation.

NOTE: Each point represents an occupation.

CHART 5. Average part-time hourly earnings as a function of part-time worker

concentration by occupation, National Compensation Survey, 1997

 Part-time average hourly earnings (dollars)

Part-time worker concentration1 (percent)

Part-time worker density1 (percent)
32 Compensation and Working Conditions Summer 2000

istics by occupation appeared to have

no effect on the ratio of part-time to

full-time average hourly earnings.

Full-time average hourly earnings also

seem to have had no effect on the parttime to full-time average hourly earnings ratio. Higher-wage jobs can be

expected in many cases to have low

earnings ratios. Lower-wage jobs, by

the same token, in many cases can

have high earnings ratios.

There is a strong correlation between full-time and part-time average

hourly earnings. Part-time earnings

are derived from their counterpart, fulltime earnings. Although this seems selfevident, it is useful to see it quantified.

Analysis of Employee Benefits Survey data show that part-time workers

received a higher percentage of their

total compensation in wages and salaries than did full-time workers.

Part-time jobs in the health field

typically paid higher average hourly

earnings than did their full-time

counterparts. This may be due to

characteristics peculiar to the health

industry. This pattern presents an interesting opportunity for further research.

1

 The National Compensation Survey defines

a part-time worker to be any employee that the

employer considers to be part time. The NCS

sample consists of 16,046 establishments that

employed 50 employees or more. The survey represents nearly 67 million workers and covers the

48 contiguous States. Agriculture, private households, and the Federal government are excluded

from the scope of the survey. 2

 For a detailed explanation of the National

Compensation Survey, see William J. Wiatrowski,

“A FORMIDABLE NEW COMPENSATION TOOL: Bureau of

Labor Statistics’ New National Compensation

Survey,” Compensation & Benefits Review, September/October 1998, pp. 29-41. The first National Compensation Survey Bulletin (3090-01)

was published in December 1996 for the Huntsville, AL, locality. 3

 Each occupation for which wage data are

collected in an establishment is evaluated based

on 10 factors, including, for example, knowledge,

complexity, and work environment. Points are

assigned based on the occupation’s ranking within

each factor. The points are summed to determine

the overall “level” of the occupation. These ratings for occupational levels are aggregated to calculate ratings for occupational group levels. 4

 For additional information, see National

Compensation Survey: Occupational Wages in

the United States, 1997, Bulletin 2519 (Bureau

of Labor Statistics, September 1999). 5

 Figures in table 1 are based on unpublished

NCS estimates of employee counts. The NCS is

designed to support estimates of occupational earnings. Estimates of the number of workers provide

a description of the size and composition of the

labor force included in the survey. However the

employment estimates are not intended for comparison with other statistical series to measure

employment trends or levels. 6

 Metropolitan areas include Metropolitan

Statistical Areas (MSAs) or Consolidated Metropolitan Statistical Areas (CMSAs), as defined by

the U.S. Office of Management and Budget.

Nonmetropolitan areas are counties not included

in MSAs or CMSAs. 7

 The average hourly earnings for metropolitan workers were $15.73; the nonmetropolitan

equivalent was $11.84. See National Compensation Survey, table 1-1. 8

 For additional information on temporary and

contingent workers and income inequality within

higher education, see Kathleen Barker, “Toiling

for Piece-Rates and Accumulating Deficits: Contingent Work in Higher Education,” in Kathleen

Barker and Kathleen Christensen, eds., Contingent Work—American Employment Relations in

Transition (Ithaca, NY, and London, Cornell University Press, 1998). 9

 n.e.c. means “not elsewhere classified.”

10 For additional information see Chris Tilly,

“Reasons for the continuing growth of part-time

employment,” Monthly Labor Review, March

1991, pp. 14-16. 11 For a discussion of this topic, see Rebecca

M. Blank, “Are Part-Time Jobs Bad Jobs?” in

Gary Burtless, ed., A Future of Lousy Jobs?

(Washington, The Brookings Institution, 1990),

p. 134. 12 Currently, the NCS uses the Occupation

Classification System (OCS), comprised of about

480 individual occupations, to cover all workers

in the civilian economy. 13 These variables were created using NCS

estimates of employee counts. See endnote 5. 14 Correlation is a data analysis tool that determines the degree to which two ranges of data

move together—that is, whether large values of

one set are associated with large values of the other

(positive correlation), whether small values of one

set are associated with large values of the other

(negative correlation), or whether values in both

sets are unrelated (correlation near zero). 15 The choice of $15 per hour as a cutoff point

between high-wage and low-wage jobs is arbitrary. 16 This tool performs linear regression analysis by using the least squares method to fit a line

through a set of observations. This method estimates how a single variable is affected by the values of one or more independent variables.

17 A fully specified model requires extensive

data on workers and firms. The National Compensation Survey does not include demographic

data or firm characteristics by occupation. 18 The word “exceeded” is used in the sense

that the ratio of average part-time earnings to average full-time earnings was greater than 1, by occupation. 19 The remaining 12 occupations, which do

not appear in table 6, are: Science technicians,

n.e.c.; biological science teachers; supervisors,

general office; management analysts; teachers’

aides; accountants and auditors; engineers, n.e.c.;

mechanical engineers; baggage porters and bellhops; clergy; operations and systems researchers

and analysts; and legislators. 20 Typically, health field work schedules must

provide 24-hour, around the clock, coverage. To

fill the more undesirable time slots, employers often recruit part-time workers and pay them a wage

premium. 21 Blank, “Are Part-Time Jobs Bad Jobs?,” p. 151.

22 Employee Benefits in Medium and Large

Private Establishments, 1997, Bulletin 2517 (Bureau of Labor Statistics, September 1999), tables

1 and 192. 23 “Employer Costs for Employee Compensation - March 1999,” USDL 99-173 (Bureau of

Labor Statistics, June 24, 1999). 24 Mark A. Brinkley, “Employer Costs for

Employee Compensation to Include Information on Part-time and Full-time Workers,”

Compensation and Working Conditions, June

1994, pp. 1-11. Brinkley found that total employer compensation costs per hour worked for

part-time workers were less than half those for

full-time workers. Table 7 confirms this with

a value of 0.47. Brinkley also found that the

wages and salaries of part-time workers were

slightly more than half those of full-time workers. A value of 0.54 from table 7 confirms this

as well. He also found that the benefit costs of

part-time employees were about one-third those

of full-time employees. Table 7 also confirms

this with a value of 0.31.
 Compensation and Working Conditions Summer 2000 33

Part-time Workers' Earnings

TABLE 2. Distribution of private industry and State and local government part-time workers by occupation, National Compensation

Survey, 1997

All part-time workers ...................................................... 100.00 100.00 82.44 100.00 17.56

White collar ............................................................................ 47.14 44.87 36.99 57.81 10.15

Professional specialty and technical ................................... 16.11 12.49 10.29 33.14 5.82

Professional specialty ................................................... 12.86 9.21 7.59 29.99 5.27

Engineers, architects and surveyors ....................... .07 .08 .06 - -

Mathematical and computer scientists..................... .08 .07 .06 - -

Natural scientists ..................................................... .08 .06 .05 .18 .03

Health related .......................................................... 5.78 6.14 5.06 4.62 .72

Teachers, college and university ............................. 1.59 .52 .43 6.61 1.16

Teachers, except college and university .................. 3.50 .94 .78 15.50 2.72

Librarians, archivists, and curators .......................... .11 .05 .04 .38 .07

Social scientists and urban planners ....................... .19 .21 .17 .11 .02

Social, recreation, and religious workers ................. .52 .38 .31 1.21 .21

Lawyers and judges ................................................ .12 - - .65 .11

Writers, authors, entertainers, athletes, and

 professionals, n.e.c ................................................ .82 .76 .62 1.12 .20

Technical ....................................................................... 3.25 3.28 2.70 3.15 .55

Executive, administrative, and managerial .......................... .82 .50 .41 2.36 .41

Executives, administrators, and managers ................... .49 .24 .20 1.66 .29

Management related ..................................................... .33 .26 .21 .71 .12

Sales .................................................................................. 15.71 18.87 15.55 .89 .16

Administrative support, including clerical ............................ 14.49 13.02 10.73 21.41 3.76

Blue collar .............................................................................. 16.43 17.73 14.61 10.35 1.82

Precision production, craft, and repair ................................ .74 .85 .70 .24 .04

Machine operators, assemblers, and inspectors ................ 1.27 1.52 1.25 .11 .02

Transportation and material moving .................................... 4.13 3.33 2.75 7.86 1.38

Handlers, equipment cleaners, helpers, and laborers ......... 10.28 12.02 9.91 2.13 .37

Service ................................................................................... 36.43 37.41 30.84 31.85 5.59

Protective service .................................................... 3.09 2.53 2.09 5.70 1.00

Food service............................................................ 16.61 18.16 14.97 9.35 1.64

Health service ......................................................... 4.67 5.19 4.28 2.22 .39

Cleaning and building service .................................. 4.74 5.22 4.30 2.53 .44

Personal service ...................................................... 7.32 6.31 5.20 12.04 2.12

TABLE 1. Ratios of average hourly earnings and average weekly hours worked by sector and area, National

Compensation Survey, 1997

Total .............................................................. 100 18 0.56 0.53

Sector

 Private industry ................................................. 78 19 .55 .54

 State and local government ............................... 22 14 .67 .49

Area

 Metropolitan ....................................................... 84 18 .55 .53

 Nonmetropolitan ................................................ 16 14 .67 .52

1

 Ratios are those of part-time workers to full-time workers.

Percent of Average

hourly

earnings

ratio1

Average

weekly hours

worked

ratio1

Workers who

are part time

Total

workers

Sector and area

Private industry part-time

workers as a

percent of—

State and local government

part-time workers

as a percent of—

Private

industry

All part-time

workers

State and local

government

Occupation Total

All part-time

workers

1

 n.e.c. means “not elsewhere classified.”

NOTE: Dash indicates that no data were reported or that data did

not meet publication criteria. Overall occupational groups may include

data for categories not shown separately. Because of rounding, sums

of individual items may not equal totals.

1
34 Compensation and Working Conditions Summer 2000

TABLE 3. Percent of private industry and State and local government workers who are part-time by

occupational group, National Compensation Survey, 1997

All part-time workers ................................................ 18 19 14

White collar ...................................................................... 16 17 12

Professional specialty and technical ............................. 14 16 12

Professional specialty ............................................. 14 16 12

Engineers, architects and surveyors ................. 1 1 -

Mathematical and computer scientists............... 1 1 -

Natural scientists ............................................... 3 3 4

Health related .................................................... 29 33 17

Teachers, college and university ....................... 24 23 25

Teachers, except college and university ............ 11 30 10

Librarians, archivists, and curators .................... 11 13 10

Social scientists and urban planners ................. 11 20 2

Social, recreation, and religious workers ........... 11 16 7

Lawyers and judges .......................................... 7 - 14

Writers, authors, entertainers, athletes, and

 professionals, n.e.c .......................................... 15 13 31

Technical ................................................................. 14 14 13

Executive, administrative, and managerial .................... 2 1 4

Executives, administrators, and managers ............. 2 1 4

Management related ............................................... 2 1 3

Sales .......................................................................... 39 39 32

Administrative support, including clerical ...................... 15 15 16

Blue collar ........................................................................ 10 10 14

Precision production, craft, and repair .......................... 2 2 1

Machine operators, assemblers, and inspectors .......... 2 2 6

Transportation and material moving .............................. 19 15 31

Handlers, equipment cleaners, helpers, and laborers ... 25 26 12

Service ............................................................................. 34 39 20

Protective service ................................................... 16 29 8

Food service ........................................................... 48 49 45

Health service ......................................................... 28 31 14

Cleaning and building service ................................. 25 30 9

Personal service ..................................................... 45 42 54

Full-time average hourly earnings ..................... 20.769 0.0390 20.701 0.0931

Density .............................................................. –0.032 0.0178 2–0.083 0.0381

Concentration .................................................... 0.169 0.3737 0.624 1.4315

Occupation Total Private

industry

State and local

government

1 n.e.c. means “not elsewhere classified.” NOTE: Dash indicates that no data were reported

or that data did not meet publication criteria.

Independent variable

All jobs High-wage jobs1

Estimated

coefficient

Standard

error

Estimated

coefficient

Standard

error

1 High-wage jobs are defined as occupations with a

full-time wage greater than or equal to $15 per hour. The

selection of $15 an hour as a cutoff point is arbitrary. 2

 Significant at the 5-percent level or better.

1

TABLE 3. Percent of private industry and State and local government workers who are part time by

occupational group, National Compensation Survey, 1997

TABLE 4. Estimates of effects of selected independent variables on part-time average hourly earnings,

National Compensation Survey, 1997
 Compensation and Working Conditions Summer 2000 35

Part-time Workers' Earnings

TABLE 5. Correlation coefficients for selected variables, National Compensation Survey, 1997

Average wage

Full time ............................................. –0.18712 0.23354 –0.29684 –0.06947 0.82187 0.60694 –0.01643 –0.06579

Part time ............................................ –0.22014 –0.04363 –0.25012 –0.00619 1 1 0.49017 0.71076

Earnings ratio ........................................ –0.04663 –0.26766 0.00692 0.07304 0.49017 0.71076 1 1

Variable

Density1 Concentration2 Part-time wage Earnings ratio3

All

jobs

High-wage

jobs4

High-wage

jobs4

High-wage

jobs4

High-wage

jobs4

All

jobs

All

jobs

All

jobs

3

1 Density is the percent of workers within a given occupation who

are part time. 2

 Concentration is the percent of all part-time workers who are in

a given occupation.

3

 Ratios are those of part-time workers to full-time workers.

4

 High-wage jobs are defined as occupations with a full-time wage

greater than or equal to $15 per hour. The selection of $15 an hour as

a cutoff point is arbitrary.

TABLE 6. Occupations in the health field for which part-time average hourly earnings exceeded full-time average

hourly earnings, selected characteristics, National Compensation Survey, 1997

 All health field related part-time workers .................. 877,004

Health related .................................................................. 632,125

Physicians ................................................................... 24,036 15 1.51

Registered nurses ....................................................... 548,536 32 1.02

Dietitians ..................................................................... 7,068 19 1.22

Occupational therapists ............................................... 10,630 23 1.12

Physical therapists ...................................................... 21,896 31 1.11

Speech therapists ....................................................... 10,539 18 1.21

Therapists, n.e.c. ......................................................... 9,420 16 1.08

Teachers, college and university

Medical science teachers ............................................ 10,041 25 1.29

Technical ......................................................................... 228,674

Clinical laboratory technologists and technicians ........ 40,050 15 1.01

Health record technologists and technicians ............... 8,866 23 1.08

Radiological technicians .............................................. 43,044 32 1.03

Licensed practical nurses ............................................ 136,714 26 1.04

Service

Dental assistants ......................................................... 2,286 22 1.06

Natural scientists

Medical scientists ........................................................ 3,878 7 1.14

Number of

part-time

workers

Percent of

workers who are

part-time

Average hourly

earnings ratio Occupation 1

2

1 Earnings ratio refers to the ratio of part-time to fulltime average hourly earnings.

2 n.e.c. means “not elsewhere classified.”
36 Compensation and Working Conditions Summer 2000

TABLE 7. Part-time to full-time ratios of compensation and benefit costs per hour worked in private industry, by occupation and

industry, Employer Costs for Employee Compensation, March 1999

All workers ....................................... 0.47 0.54 0.31 0.19 0.22 0.18 0.22 0.59

Occupation ................................................

White collar ........................................... .51 .56 .35 .24 .28 .22 .23 .64

Sales................................................ .40 .43 .31 .18 .19 .20 .22 .53

Administrative support,

 including clerical ............................ .68 .77 .45 .34 .45 .25 .34 .82

Blue collar ............................................. .53 .59 .39 .21 .31 .27 .42 .63

Service .................................................. .63 .71 .40 .20 .28 .14 .25 .73

Industry ...................................................

Goods producing ................................... .51 .59 .33 .15 .28 .18 .13 .71

Service producing ................................. .49 .54 .34 .20 .25 .19 .24 .63

Retail trade ...................................... .54 .58 .43 .19 .33 .25 .45 .64

Services .......................................... .60 .67 .42 .28 .42 .23 .30 .74

TABLE 8. Differences in employer compensation costs per hour worked between full-time and part-time workers in private industry,

by occupational and industry group, Employer Costs for Employee Compensation, March 1999

All workers ....................................... $11.35 $7.19 $4.16 $1.18 $0.52 $1.14 $0.54 $0.74

Occupation ................................................

White collar ........................................... 12.53 8.08 4.45 1.44 .51 1.18 .62 .67

Sales................................................ 12.55 9.28 3.27 .83 .51 .76 .39 .76

Administrative support,

 including clerical ............................ 5.54 2.85 2.70 .83 .21 1.06 .35 .23

Blue collar ............................................. 8.98 5.42 3.56 .85 .51 1.04 .40 .72

Service .................................................. 4.31 2.48 1.83 .51 .18 .65 .15 .33

Industry ...................................................

Goods producing ................................... 11.42 6.65 4.77 1.31 .62 1.40 .75 .62

Service producing ................................. 10.72 6.99 3.72 1.14 .44 1.02 .47 .63

Retail trade ...................................... 6.32 4.53 1.79 .54 .18 .47 .11 .48

Services .......................................... 8.28 5.18 3.10 1.09 .26 .92 .39 .44

Occupation and industry

Total

compensation

Wages

and

salaries

Retirement

and

savings

Benefits

Legally

required

benefits

Insurance

Supplemental

pay

Paid

leave Total

Benefits

Legally

required

benefits

Retirement

and

savings

Insurance

Supplemental

pay

Paid

leave

Total

Total

compensation

Wages

and

salaries

Occupation and industry