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U.S. Department of Commerce

Economics and Statistics Administration

U.S. CENSUS BUREAU

Dynamics of Economic Well-Being:

Spells of Unemployment 2001–2003

Household Economic Studies

P70-105

Issued March 2006

Current

Population

Reports

By 

Alfred O. Gottschalck

This report presents data

from the 2001 panel of the

Survey of Income and

Program Participation (SIPP)

on how long people

remained unemployed during each of the times

(spells) they experienced

unemployment. The data

cover the period of January

2001 through December

2003. The table in the

appendix displays the

detailed statistical data

analyzed in this report.

The labor market of the

United States is dynamic

and flexible, changing as

people enter and exit it or

change jobs within it. As

the overall structure of the

U.S. economy continues to

shift from a manufacturing

base to a service-oriented

base, so does the demand

for particular types of

labor.1 Data on spells of

unemployment provide an

insight into how easily the

market allows people to

1 For a more thorough discussion of U.S. economic structural

change and its relationship to

changing labor demands, see Kevin Murphy and Finis

Welch, “Industrial Change and the Rising Importance

of Skill,” pages 101–132 in Uneven Tides: Rising

Inequality in America, Sheldon H. Danziger and Peter

Gottschalk, eds., 1993; George E. Johnson, “Changes

in Earnings Inequality: The Role of Demand Shifts,”

pages 41–54 in Journal of Economic Perspectives,

Spring 1997; and Daron Acemoglu, “Technical

Change, Inequality, and the Labor Market,” pages

7–72 in Journal of Economic Literature, March 2002.

SIPP—A Longitudinal Survey

The SIPP is a longitudinal panel survey that interviews a representative sample of U.S. households

every 4 months. The population represented (the

population universe) is the civilian noninstitutionalized population of the United States. The

median spell duration estimates in this report

relate to the civilian noninstitutionalized population of the United States 15 years and older at the

end of the 2001 SIPP panel in December 2003. 

The core content of the SIPP identifies demographic characteristics, labor force participation,

government program participation, and various

income sources of members of sampled households. The longitudinal estimates presented here

are based on people who were interviewed in all

waves of the 2001–2003 reference period, or for

whom imputed information exists. Each wave of

the SIPP panel consists of four rotations interviewed in turn in consecutive months. Efforts

were made during the life of the panel to ensure

that the sample remained representative of the

noninstitutionalized population of the United

States. If the people included in the estimates

have different experiences of employment and

unemployment than the people who did not

respond initially, left the sample, or missed two or

more consecutive waves, these longitudinal estimates may be biased. 

make these transitions and respond to

shifts in labor demand.

Unemployment Spells by Sex

The median duration of a spell of unemployment for individuals was 2.4 months

during the period from January 2001
through December 2003.2 The

median spell of unemployment for

women (2.2 months) was shorter

than that for men (2.6 months),

which may reflect a segmentation

between men and women in the

types of jobs they were seeking,

the intensity of their job searches,

the conditions under which they

would accept jobs (reservation

wage,3 for example), and other

factors (Figure 1).

Unemployment Spells by Race

and Hispanic Origin

Non-Hispanic White workers experienced the shortest spells of unemployment, while Black workers and

Asian and Pacific Islander workers

had the longest (Figure 1).4 Black

workers had a median spell length

that was 43 percent longer than

that of non-Hispanic White workers;

Asian and Pacific Islander workers

had a median spell length that was

38 percent longer. Male and female

Black workers had unemployment

spell durations that were longer

than their non-Hispanic White counterparts. Male Black workers had a

median duration of 3.1 months and

female Black workers a median of

2 U.S. Census Bureau

2 The estimates in this report are based

on responses from a sample of the population and may differ from the actual values

because of sampling variation and other factors. As a result, apparent differences

between the estimates for two or more

groups may not be statistically significant.

All comparative statements have undergone

statistical testing and are significant at the

90-percent confidence level unless otherwise

noted. All spells are included in the statistical analysis, so individuals may be represented more than once. 3 The lowest wage an individual is willing

to accept in order to enter employment. 4 Because Hispanics may be any race,

data in this report for Hispanics overlap

slightly with data for the Black population

and the Asian and Pacific Islander population. For this report, the number of Hispanic

Black workers comprised 1 percent of total

workers and the number of Hispanic Asian

and Pacific Islander workers comprised less

than one-half of 1 percent of total workers.

Data for American Indians and Alaska

Natives are not shown in this report because

of their small sample sizes.

2.8 months, while male and female Unemployment Spells by Age 

non-Hispanic White workers had Spell length and age were posi- median durations of 2.3 and 2.0 tively related, with the median months, respectively. Female unemployment spell duration Hispanic workers had an unemploy- increasing with age (Figure 2). The ment spell duration (2.5 months) shortest median spell length was that was longer than that of female 1.8 months for 16-to-19-year-olds; non-Hispanic White workers the longest was 3.1 months for (2.0 months).

Figure 1.

Median Duration of Spells of Unemployment by Sex, 

Race, and Hispanic Origin: 2001–2003

Note: Includes all unemployment spells for people in the labor force; people of Hispanic 

origin may be any race.

Source: U.S. Census Bureau, Survey of Income and Program Participation, 2001 panel.

(In months)

Hispanic women

Hispanic men

Asian and

Pacific Islander women

Asian and

Pacific Islander men

Black women

Black men

White, non-Hispanic

women

White, non-Hispanic men

Hispanic

Asian and Pacific Islander

Black

White, non-Hispanic

Women

Men

Total workers 2.4

2.6

2.2

2.1

3.0

2.9

2.7

2.3

2.0

3.1

2.8

3.0

2.9

2.8

2.5

Demographic Group
people aged 45–54. Male 20-to24-year-olds (2.4 months) had

longer spell lengths than their

female counterparts (1.8 months),

while for the other age groups, the

male and female spell durations

were not statistically different from

each other (Figure 3). Of the male

age cohorts, 16-to-19-year-olds

had the shortest spell lengths (1.8

months). Among the female age

cohorts, 16-to-19-year-olds had the

shortest spell lengths (1.7

months), compared with 25-to-34-

year-olds (2.5 months), 35-to-44-

year-olds (2.6 months), 45-to-54-

year-olds (2.8 months), and those

aged 55 and older (2.5 months).

The shorter spell durations for

younger workers relative to older

workers may be partly a result of

younger workers possessing more

current job skills that the modern

service-oriented labor market

demands and being less constrained by family responsibilities,

thereby allowing them to transition

between jobs more easily and

quickly. Also, younger workers

tend to be less well-paid than older

workers, and since more jobs are

available in the lower wage ranges,

younger workers may be able to

transition between lower-paying

jobs more quickly.

Unemployment Spells 

by Education

Educational attainment was

inversely related to spell length.

The greater the educational attainment, the shorter the spell of unemployment (Figure 4). Individuals

with less than a high school education had a median spell length that

was 35 percent longer than that of

people with at least some college

education. The longer spell duration for workers who did not complete high school relative to more

highly educated workers may partly

reflect the diminished employment

opportunities for less-skilled

U.S. Census Bureau 3

55+

45 to 54

35 to 44

25 to 34

20 to 24

16 to 19

Figure 2.

Median Duration of Spells of Unemployment 

by Age: 2001–2003

Note: Includes all unemployment spells for people in the labor force.

Source: U.S. Census Bureau, Survey of Income and Program Participation, 2001 panel.

(In months)

Age (years)

2.5

1.8

2.0

2.6

2.6

3.1

55+

45 to 54

35 to 44

25 to 34

20 to 24

16 to 19

Figure 3.

Median Duration of Spells of Unemployment 

by Age and Sex: 2001–2003

Note: Includes all unemployment spells for people in the labor force.

Source: U.S. Census Bureau, Survey of Income and Program Participation, 2001 panel.

(In months)

Age (years)

Men

Women

1.8

1.7

2.4

1.8

2.8

2.5

2.7

2.6

3.3

2.8

2.6

2.5
workers over the time period examined in this report.5

Source of the Data

The population represented (the

population universe) in the 2001

SIPP is the civilian noninstitutionalized population of the United

States. The SIPP is a longitudinal

survey conducted at 4-month intervals. The data in this report refer

to the period from January 2001

through December 2003. The

institutionalized population, which

is excluded from the population

universe, is composed primarily of

the population in correctional institutions and nursing homes (91 percent of the 4.1 million institutionalized population in Census 2000).

Accuracy of the Estimates

Statistics from surveys are subject

to sampling and nonsampling error.

All comparisons presented in this

report have taken sampling error

into account and are significant at

the 90-percent confidence level

unless otherwise noted. This

means the 90-percent confidence

interval for the difference between

the estimates being compared does

not include zero. Nonsampling

errors in surveys may be attributed

to a variety of sources, such as how

the survey is designed, how respondents interpret questions, how able

and willing respondents are to provide correct answers, and how

accurately the answers are coded

and classified. The U.S. Census

Bureau employs quality control procedures throughout the production

4 U.S. Census Bureau

5 See Sheldon H. Danziger and Peter

Gottschalk, America Unequal, 1995, for a

discussion of the diminished employment

opportunities for less-skilled workers relative

to more highly skilled workers in the United

States.

At least some college

High school graduate

Less than

high school graduate

Figure 4.

Median Duration of Spells of Unemployment by 

Educational Attainment for People 21 

and Older: 2001–2003

Note: Includes all unemployment spells for people in the labor force.

Source: U.S. Census Bureau, Survey of Income and Program Participation, 2001 panel.

(In months)

Educational Attainment

3.1

2.8

2.3

Description of Concepts

Spell of unemployment: An uninterrupted period of months in

which an individual was unemployed. For this analysis, individuals

were unemployed in a given month only if they had no job all month

and spent at least 1 week on layoff or looking for work. This definition of unemployment differs slightly from the definition used for the

Current Population Survey (CPS). The SIPP considers some people

who were absent without pay from a job because of layoff to be “with

a job”; these people are excluded from the definition of unemployment used here, but not necessarily from the CPS definition. 

Layoff: An individual was on “layoff” if the individual (1) was

released from a job because of slack work, material shortages,

inventory taking, plant remodeling, installation of machinery, or

other similar reasons; and (2) anticipated being recalled to the job. 

Looking for work: An individual “looked for work” in a given

month if the individual (1) was without a job during at least 1 week

during the month; and (2) tried to get work or establish a business

or profession in that week.

Median spell duration: The value of spell length that divides the

distribution of spells by length into two equal parts: one half being

longer and the other half shorter than the median.

Civilian noninstitutionalized population 15 years and older:

The population 15 years and older that does not reside in institutions, such as correctional institutions and nursing homes.

Labor force: An individual was considered to be in the labor force if

the individual (1) was employed in a given month; or (2) was unemployed in a given month and actively looking for work or on layoff.
process, including the overall

design of surveys, the wording of

questions, the review of the work of

interviewers and coders, and the

statistical review of reports to minimize these errors.

The SIPP weighting procedure uses

ratio estimation, whereby sample

estimates are adjusted to independent estimates of the national

population by age, race, sex, and

Hispanic origin. This weighting

partially corrects for bias due to

undercoverage, but biases may still

be present when people who are

missed by the survey differ from

those interviewed in ways other

than age, race, sex, and Hispanic

origin. How this weighting procedure affects other variables in the

survey is not precisely known. All

of these considerations affect

comparisons across different surveys or data sources.6

For further information on the

source of the data and accuracy of

the estimates, including standard

errors and confidence intervals, go

to <www.sipp.census.gov/sipp

/sourceac/S&A2_SIPP2001

_w1tow9_20050214.pdf> or

contact Dennis Sissel, Demographic

Statistical Methods Division, at

<charles.d.sissel@census.gov>.

Contacts

Labor Force Statistics— 

Statistical Information Staff

301-763-3242 

hhes-info@census.gov

U.S. Census Bureau 5

6 For a more detailed discussion of SIPP

sampling and weighting, see 

<www.sipp.census.gov/sipp/sam_and

_wt.html>.

This report—

Thomas J. Palumbo

Branch Chief

Labor Force and Transfer Program

Statistics Branch

301-763-3230

User Comments

The Census Bureau welcomes the

comments and advice of users of

its data and reports. If you have

any suggestions or comments,

please send an e-mail inquiry to

<hhes-info@census.gov>.

Suggested Citation

Gottschalck, Alfred O. Dynamics of

Economic Well-Being: Spells of

Unemployment, 2001–2003.

Current Population Reports, 

P70-105. U.S. Census Bureau,

Washington, DC. 2006.
6 U.S. Census Bureau

Appendix.

Unemployment Spells by Sex, Age, Educational Attainment, Race, and Hispanic Origin:

2001–2003

Characteristic

Total number

of spells

(thousands)

Median length

of spells

(months) Standard error

Total..................................................

Sex

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women . ......................................................

Age

16 to 19 years .................................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

20 to 24 years .................................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

25 to 34 years .................................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

35 to 44 years .................................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

45 to 54 years .................................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

55 years and over ..............................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

Educational Attainment (people 21 years and older)

Less than high school graduate . .................................

High school graduate ...........................................

At least some college ...........................................

Race/Ethnicity

White .........................................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

Not of Hispanic origin .........................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women ...................................................

Black . . . ......................................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

Asian and Pacific Islander .......................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

Hispanic origin (any race) .......................................

Men . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Women .....................................................

Year Spell Started

2001. . ........................................................

2002. . ........................................................

2003. . ........................................................

49,417

24,819

24,598

10,714

5,720

4,993

9,307

4,863

4,444

10,483

4,895

5,589

9,244

4,349

4,895

6,585

3,459

3,126

3,084

1,533

1,551

7,021

11,645

17,790

36,879

18,655

18,224

30,338

15,448

14,889

9,311

4,456

4,855

2,078

1,083

995

7,355

3,636

3,719

16,399

18,434

14,583

2.4

2.6

2.2

1.8

1.8

1.7

2.0

2.4

1.8

2.6

2.8

2.5

2.6

2.7

2.6

3.1

3.3

2.8

2.5

2.6

2.5

3.1

2.8

2.3

2.2

2.4

2.0

2.1

2.3

2.0

3.0

3.1

2.8

2.9

3.0

2.9

2.7

2.8

2.5

1.9

2.4

3.0

0.08

0.11

0.10

0.10

0.15

0.13

0.17

0.25

0.14

0.15

0.24

0.20

0.16

0.22

0.22

0.15

0.21

0.33

0.27

0.38

0.38

0.12

0.16

0.12

0.08

0.13

0.11

0.09

0.14

0.08

0.19

0.15

0.25

0.44

0.62

0.62

0.20

0.29

0.28

0.06

0.09

0.10

Source: U.S. Census Bureau, 2001 SIPP panel, January 2001–December 2003.
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