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Acknowledgments

This report was prepared under the general direction of Kathleen S. Short, Chief,

Poverty and Wealth Statistics Branch. The tables for this report were programmed and

prepared by Caroline Carbaugh under the general direction of Angela M. FeldmanHarkins, Chief, Computer Programming and Applications Staff. Statistical assistance

was provided by Astrid V. Clarke, Bernadette D. Proctor, and Jean E. Tash. Overall

direction was provided by Charles T. Nelson, Assistant Division Chief (Economic

Characteristics), Housing and Household Economic Statistics Division. Peer review was

provided by John Coder, (Housing and Household Economic Statistics Division),

William Prosser (Department of Health and Human Services), and Larry Radbill (Joint

Economic Committee).

Survey design and data operations were coordinated by Enrique J. Lamas, Chief,

Income Surveys Branch, Demographic Surveys Division. Data processing activities

were directed by Donna Riccini, Chief, Income Surveys Programming Branch, Demographic Surveys Division.

Data collection was conducted by the Bureau of the Census interviewers under the

overall direction of Stanley D. Matchett, Chief, Field Division.

Sampling, estimation and statistical review were conducted by Vicki Huggins, Chief,

Survey of Income and Program Participation Branch, and Suzanne Dorinski, Demographic Statistical Methods Division.

The staff of Administrative and Publications Services Division, Walter C. Odom,

Chief, provided publication planning, design, composition, and printing planning and

procurement; Frances B. Scott edited and coordinated the publication.







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HOUSING AND HOUSEHOLD

ECONOMIC STATISTICS DIVISION

Daniel H. Weinberg, Chief

SUGGESTED CITATION

Shea, Martina, Dynamics of Economic Well-Being: Poverty, 1990 to 1992

U.S. Bureau of the Census. Current Population Reports, P70-42,

U.S. Government Printing Office, Washington, DC, 1995.

For sale by Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.

BUREAU OF THE CENSUS

Martha Farnsworth Riche, Director

Harry A. Scarr, Deputy Director

Paula J. Schneider, Principal Associate

Director for Programs

William P. Butz, Associate Director

for Demographic Programs

ECONOMICS

AND STATISTICS

ADMINISTRATION

Economics and Statistics

Administration

Everett M. Ehrlich, Under Secretary

for Economic Affairs
Page

Introduction......................................................................................... 1

Technical Note................................................................................... 1

Highlights ........................................................................................... 2

Poverty: 1990 to 1992 ............................................................................. 2

Monthly Measures of Poverty................................................................... 3

Family and Marital Status .................................................................... 3

Race and Hispanic Origin .................................................................... 5

Age ............................................................................................ 6

Education...................................................................................... 6

Employment Status ........................................................................... 7

Disability Status ............................................................................... 7

Residence ..................................................................................... 7

Region ......................................................................................... 7

Annual Measures of Poverty.................................................................... 9

TEXT TABLES

A. Poverty Status, by Family and Marital Status: 1991, 1990, and 1987 .................. 5

B. The Chronically Poor and Median Spell Durations, by Family and Marital Status:

1990 to 1991 and 1987 to 1988 ........................................................ 5

C. Poverty Status, by Race and Hispanic Origin: 1990 ..................................... 7

D. Poverty Status, by Age: 1990 ............................................................. 8

E. Poverty Status, by Education, Employment, and Disability Status: 1990 ............... 9

F. Poverty Status, by Residence and Region: 1990 ........................................ 9

G. Percent of Persons Entering and Exiting Poverty: 1990 to 1991 and 1987 to 1988 ... 10

H. Profile of the Long-Term Poor: 1990 to 1991 ............................................ 11

FIGURES

1 Poverty Rates: 1990 and 1991 ............................................................ 4

2. Percent of Persons Who Were Chronically Poor, by Various Characteristics:

1990 to 1991 .............................................................................. 4

3. Distribution of Poverty Spells, by Spell Length: 1990 to 1992........................... 6

4. Median Durations of Poverty Spells, by Various Characteristics: 1990 to 1992........ 8

DETAILED TABLES

1. Average Monthly Poverty, by Selected Characteristics: 1990 and 1991................ 13

2. Persons Poor 2 or More Months, by Selected Characteristics: 1990 and 1991........ 15

3. Persons Poor Each Month of 1990 and 1991, by Selected Characteristics ............ 17

4. Spells of Poverty for Persons Who Became Poor During the 1990 SIPP Panel, by

Selected Characteristics.................................................................. 19

5. Transitions Into and Out of Poverty, by Selected Characteristics: 1990 to 1991....... 21

iii

Contents
APPENDIXES

A. Overview of the SIPP Program............................................................ A-1

B. Definitions and Explanations............................................................... B-1

C. Source and Accuracy of the Estimates ................................................... C-1

D. Description of SIPP 1990 Panel File and Data Quality .................................. D-1

E. Supplementary Tables: 1987 and 1988................................................... E-1

APPENDIX TABLES

A-1. Topical Modules for the 1990 SIPP Panel................................................ A-2

A-2. Design of the 1990 SIPP Panel ........................................................... A-2

B-1. Income Sources Included in Monthly Cash Income...................................... B-3

B-2. Weighted Average Poverty Thresholds in 1990 and 1991............................... B-4

C-1. Statistics of Persons 0+ for Longitudinal Panels and Calendar Years: 1987 and

1990 ....................................................................................... C-2

C-2. 1992 CPS Coverage Ratios ............................................................... C-3

C-3. SIPP Generalized Variance Parameters for Estimates from the 1987 Longitudinal

Panel File.................................................................................. C-7

C-4. SIPP Generalized Variance Parameters for Estimates from the 1990 Longitudinal

Panel File.................................................................................. C-7

C-5. SIPP Indirect Generalized Variance Parameters for Annual Estimates Based on

Monthly Averages from the 1987 Cross-Sectional Files................................ C-7

C-6. SIPP Indirect Generalized Variance Parameters for Annual Estimates Based on

Monthly Averages from the 1990 Cross-Sectional Files................................ C-7

C-7. Standard Errors of Estimated Numbers of Persons...................................... C-8

C-8. Standard Errors of Estimated Percentages of Persons .................................. C-8

C-9. Standard Errors of Survival Rates and Median Spell Durations for Persons Who

Became Poor During the 1990 SIPP Panel, by Selected Characteristics............. C-9

C-10. Standard Errors of Survival Rates and Median Spell Durations for Persons Who

Became Poor During the 1987 SIPP Panel, by Selected Characteristics ............. C-11

D-1. Percent Distribution: Three Categories of Sample Persons: 1990 SIPP Panel ........ D-4

D-2. Average Monthly Nonfarm Poverty and Household Participation in Means-Tested

and Nonmeans-Tested Government Programs--SIPP Panels: First Quarter 1984 to

Fourth Quarter 1993 ...................................................................... D-5

D-3. Comparison of CPS and SIPP Poverty Rates, by Selected Characteristics: 1990

and 1991 .................................................................................. D-7

D-4. Comparison of 1990 to 1991 Year-to-Year Percentage Point Changes in Poverty

Rates Between CPS and SIPP .......................................................... D-8

E-1. Average Monthly Poverty, by Selected Characteristics: 1987 and 1988................ E-1

E-2. Persons Poor 2 or More Months, by Selected Characteristics: 1987 and 1988........ E-3

E-3. Persons Poor Each Month of 1987 and 1988, by Selected Characteristics ............ E-5

E-4. Spells of Poverty for Persons Who Became Poor During the 1987 SIPP Panel, by

Selected Characteristics.................................................................. E-7

E-5. Transitions Into and Out of Poverty, by Selected Characteristics: 1987 to 1988....... E-9

iv
Dynamics of Economic Well-Being: Poverty, 1990 to 1992

INTRODUCTION

This report uses data from the Survey of Income and

Program Participation (SIPP) to examine the incidence

of poverty at a point in time and over a 32-month period.

It presents data from the complete panel file of the 1990

SIPP which covers the time period from October 1989

through August of 1992. Descriptions of the SIPP program and the 1990 panel file are contained in appendixes A and D, respectively.

SIPP enables comparisons of poverty rates among

groups of persons of different demographic and socioeconomic characteristics. It also can be used to study

the distribution of poverty spell durations. The panel file

contains monthly information on income as well as on

many other characteristics which can vary over the

panel, such as residence and labor force status. Efforts

were made during the life of the panel to follow persons

who moved to ensure that the sample remained representative of the noninstitutional population of the United

States. Persons are characterized by the income and

poverty status of their respective family unit based on

living arrangements each month during the period of

study.

It should be noted that some longitudinal estimates

presented here are based on responses of persons who

were interviewed in all eight waves of the 1990 panel.

Other longitudinal estimates are based on respondents

interviewed in all waves of a particular calendar year.

Insofar as persons who left the panel differed in their

experience of poverty from those who did not, these

longitudinal estimates may be biased.

All demographic surveys, including CPS and SIPP,

are affected by undercoverage of the population. This

undercoverage results from missed housing units and

missed persons within sample households. Compared

to the level of the 1980 Decennial Census, overall

undercoverage in SIPP is about 7 percent. Undercoverage varies with age, sex, and race. For some groups,

such as 20 to 24 year old Black males, the undercoverage is as high as 27 percent compared to the census. It

is important to note that the survey undercoverage is an

addition to the decennial census undercoverage, which

in 1980 was estimated to be about 1 percent overall and

about 8.5 percent for Black males. The weighting procedures used by the Census Bureau partially correct for

the bias due to undercoverage. However, its final impact

on estimates is unknown.

The detailed tables cover the years 1990 and 1991

from the 1990 SIPP panel, as well as the years 1987 and

1988 from the 1987 panel of SIPP for some of the

measures (appendix E). The later panel coincided with

the latest recessionary period from July 1990 to March

1991, while no recession took place during the 1987

panel. This could explain some of the data described

below.

Technical note. Some of the estimates presented

below are distributions of spell duration for individuals

with different characteristics. We use a survival analysis

technique to derive these distributions and the resulting

estimates of median spell duration for persons observed

entering a spell of poverty during the 32 months of the

panel. We consider only individuals who were present in

the survey all 32 months. One alternative would have

been to include all persons up until the time of attrition.

It is, however, extremely difficult to come up with appropriate weights for such an analysis and it was therefore

not attempted here.

Spells of poverty must have an observed beginning,

i.e. have to be preceded by one or more months of

‘‘nonpoverty’’ during the panel. In addition, periods of

poverty must last at least 2 months in order to be

counted as spells. Furthermore, poverty spells must be

more than 1 month apart in order to be counted as

separate spells. If two potential spells are separated by

only 1 month, they count as one spell. The connecting

month is counted as part of the resulting spell. A spell is

observed either until it ends or until it is right-censored.1 2

1

Since an individual must have completed interviews for all months

of the panel in order to be included in the sample, rightcensoring

occurs only if an individual is still poor in the last month of the panel. 2 The probability of exiting a spell in month t, given that the person

was experiencing a spell in the beginning of that month, is defined as

h~t!= exits ~t!

prog ~t!2~rcens ~t!/2!

where exits(t) denotes the number of spell exits in month t, prog(t) is

the number of spells that were in progress in the beginning of month

t, and rcens(t) is the number of spells which were right-censored in

month t.

The survival rate in month t, which is the probability that a spell lasts

longer than t months, can then be written as

S~t! =

t

p

k51 ~1-h~k!!

The survival function evaluated at t gives the probability that an

entrant into poverty is still poor t time periods later.

The median survival time or spell duration M can be estimated by

linear interpolation. Let [t, t+1) be the interval such that S(t)>=.5 and

S(t+1)< .5. Then

Mˆ 5 t 1

S~t!21/2

S~t!-S~t+1!

1
Since a poverty spell must be preceded by a period of

nonpoverty, left-censored spells are not included in our

analysis. Observations are left-censored when the beginning of a spell of interest is not observed, that is, a spell

began at some time before the reference period.

While dynamic estimates may be unbiased for spells

with observed beginnings in the reference period, there

remains concern about the deletion of left-censored

spells from such analyses. There may be particular

characteristics of persons, associated with the experience of very long spells, that precludes their inclusion in

our sample. For example, in our analysis, which is

restricted to persons in sample the entire period, selecting spells with observed beginnings leads to a sample

without those persons who were poor from the first

month of life onward. Even if one defines the spells of

those ‘‘born into poverty’’ as spells with observed beginnings, the problem of unavailable appropriate weights

make their inclusion all but impossible. Studies of spells

with observed beginnings might result in reasonable

estimates of spell distribution and median duration for

such spells with observed beginnings, but it might result

in downward biased estimates of the median duration of

all spells.

HIGHLIGHTS

(The numbers in parentheses denote the 90-percent

confidence intervals)

x In an average month of 1990, 31.8 (±1.1) million

persons were poor, representing 12.9 (±0.4) percent

of the population. About 45.6 (±1.4) million persons

were poor at least 2 months in 1990.

x In an average month of 1991, 33.9 (±1.1) million

persons were poor, representing 13.6 (±0.5) percent

of the population, and an increase of 2.1 million over

1990. About 48.5 (±1.5) million persons were poor at

least 2 months in 1991.

x A substantial proportion of the population was poor on

a long-term basis: 4.5 (±0.3) percent or 10.6 (±0.8)

million were poor all 24 months of 1990 and 1991.

x Half of all poverty spells lasted longer than 4.0 (±0.4)

months. While half of all spells experienced by Whites

lasted longer than 3.9 (±0.1) months, half of all spells

experienced by Blacks and persons of Hispanic origin

lasted longer than 5.8 (±1.0) and 4.9 (±0.5) months,

respectively.

x Seven (±0.4) percent of persons in married-couple

families were poor in an average month of 1990, but

35 (±1.7) percent of persons in female householder

families. Likewise, persons in married-couple families

were much less likely to be poor continuously for all

24 months of 1990 and 1991 than persons in femalehouseholder families, 1 (±0.2) versus 18 (±1.7) percent.

x Blacks were almost three times as likely as Whites to

be poor in an average month, and persons of Hispanic origin had a poverty rate intermediate between

Whites and Blacks.

x Every fifth (±1.0) child was poor in an average month

of 1990, compared to 11 (±0.5) percent of non-elderly

adults and 9 (±1.0) percent of the elderly.

x Forty (±3.9) percent of the unemployed were poor in

an average month of 1990, followed by 12 (±1.3)

percent of part-time workers, and 4 (±0.4) percent of

full-time workers. The proportion of those not in the

labor force who were poor was intermediate between

part-time workers and the unemployed, 18 (+0.9)

percent.

x Twenty-one (±2.1) percent of persons who were poor

in 1990 were not poor in 1991. Children and the

elderly, although not significantly different from one

another, were less likely to exit poverty than nonelderly adults.

x There was a greater probability of becoming poor in

the recessionary period of 1990-91 and a lower

probability of leaving poverty compared with the 1987-88

period during which only 2.2 (±0.3) percent became

poor while one-fourth (±2.8) of the poverty population

became nonpoor.

POVERTY: 1990 TO 1992

SIPP allows us to deal with the static as well as the

dynamic aspects of poverty. It is the latter aspect that

provides additional insight into the nature of poverty.

Unlike the poverty and income data collected in the

Current Population Survey (CPS), which does not allow

analysis of change in income and poverty status for

particular individuals, longitudinal data make it possible

to measure movement along the income distribution and

into and out of poverty for the same persons over the life

of the panel.

The SIPP collects income information and family

composition on a monthly basis. Thus, poverty status

can be determined on a monthly basis, by comparing

monthly family income to monthly thresholds. Monthly

thresholds rise from month to month by the same

percentage as the Consumer Price Index (CPI). In

addition, annual poverty estimates can be obtained by

summing monthly family income over the year and

comparing it to the sum of the 12 corresponding monthly

thresholds, based on family size and composition in

each month.

These annual poverty estimates based on the SIPP

differ from the official poverty estimates that are based

on the March Supplement to the CPS. In the CPS,

poverty status is based on responses to income questions which refer to income received in the previous

calendar year. Annual poverty thresholds are based on

2
family composition fixed as of the survey date and

assumed to be constant over the previous year (in the

case of 1990 poverty status, the data were collected in

the March 1991 CPS).3

Most of the estimates in this report are based on a

monthly determination of poverty status. It is useful to

obtain poverty estimates based not only on yearly

income but also on monthly income, in order to capture

short-term economic hardship. In addition, eligibility for

means-tested assistance programs is based on monthly

rather than annual income.

Our analysis focuses on four monthly measures of

poverty as derived from the SIPP:

a) the number and percent of persons who

were poor in an average month of 1990

(1991).

b) the number and percent of persons who

were poor 2 months or more during 1990

(1991).

c) the number and percent of persons who

were poor each month of 1990 and 1991.

Phrases like long-term and chronic poverty

are used interchangeably to denote this type

of poverty.

d) the length and distribution of poverty spells.

In addition, this report will examine transitions into

and out of poverty during 1990 and 1991 based on an

annual measure of poverty:

e) the number and percent of persons who

were poor in one year but not the other, i.e.

exits from and entries into poverty.

f) the number and percent of persons who were

poor in both 1990 and 1991.

Examining poverty with longitudinal data allows one

to distinguish between short and long term poverty.

There are reasons to be concerned about persons who

are poor for very long periods in contrast to persons who

remain poor for only short periods. Much public policy

debate is concerned with persons and families who

remain poor for long periods of time. The official measure of poverty does not allow us to distinguish between

short and long spells of poverty. SIPP, however, allows

longitudinal analysis of poverty.

Monthly Measures of Poverty

About 31.8 million persons were poor in an average

month of 1990, and 33.9 million were poor in 1991,

representing 12.9 and 13.6 percent of the population,

respectively (table A). Substantially more persons were

poor for 2 or more months than in an average month,

showing considerable movement in and out of poverty.

About 45.6 million persons were poor at least 2 months

in 1990, representing 18.9 percent of all persons, significantly smaller than the 48.5 million (19.8 percent) in

1991. A substantial proportion of the population was

poor on a long-term basis: 4.5 percent (10.6 million)

were poor all 24 months of 1990 and 1991 (see table B

and figures 1 and 2).

The median duration of poverty spells that began

after October 1989 was 4.0 months for all persons, the

same as during the 1987 panel.4 This means that half of

all poverty spells lasted longer than 4 months. Figure 3

shows the percent distribution of poverty spells by spell

lengths. While 50 percent of spells lasted 2 to 4 months,

smaller proportions of spells fell into subsequent length

categories: for instance, while 19.0 percent of spells

lasted between 5 and 8 months, only 8.0 percent lasted

between 9 and 12 months.

Family and Marital Status. Single-parent families generally have female householders, and persons in female

householder families are much more likely to be poor

than persons in married-couple families. As can be seen

in tables A and B, 35.2 percent of persons in female

householder families were poor in an average month of

1990, 43.1 percent were poor at least 2 months, and

17.6 percent were poor continuously for 24 months. The

corresponding proportions of persons in married-couple

families who were poor were significantly smaller, 7.0,

12.7, and 1.4 percent respectively. Unrelated individuals

had poverty rates that were between those in femalehouseholder and married-couple families.

Comparisons over time show few differences. However, persons in married-couple families, in contrast to

persons in other types of families, were less likely to be

poor in an average month of 1990 (7.0 percent) than of

1987 (7.9 percent).

The length of time spent in poverty differed by family

type. Persons in female householder families had significantly longer poverty spells than persons in marriedcouple families. The median poverty spell experienced

by persons in female householder families lasted 6.5

months, compared to 3.8 months for persons in marriedcouple families (see table B).

Marital status of persons 18 years and older is

correlated with poverty. Married persons were less likely

to be poor than never married persons, and the latterwere less likely to be poor than separated, divorced, or

widowed persons. Table A shows that the average

monthly poverty rate for married persons was 5.8 percent in 1990, significantly lower than the 15.1 percent for

3 Comparisons of CPS and SIPP annual poverty estimates can be

made by fixing household composition in the SIPP as of March of the

following year. Significant differences in poverty rates still remain.

Appendix D describes possible sources of differences in estimates

from the two surveys. See also Coder and Scoon-Rogers’ forthcoming

working paper ‘‘Evaluating the Quality of Income Data Collected in the

Annual Supplement to the March Current Population Survey and the

Survey of Income and Program Participation.’’

4

Restricting the observation period of the 1990 panel to 28 months,

i.e. the length of the 1987 panel, did not significantly change the

estimated median spell duration.

3
Figure 1.

Poverty Rates: 1990 and 1991

Poor 2 or

more months

in 1990

Percent

Poor 2 or

more months

in 1991

Poor in an

average month

of 1990

18.9

19.8

12.9

Poor in an

average month

of 1991

Poor all months

of 1990 and 1991

13.6

4.5

Figure 2.

Percent of Persons Who Were Chronically Poor,

by Various Characteristics: 1990 to 1991

Percent

All persons

White

Black

Hispanic origin1

Under 18 years

65 years and over

Less than 4 years

of high school

Persons in marriedcouple families

Persons in femalehouseholder families

Unemployed

Separated, divorced

or widowed

4.5

3.0

13.9

10.4

7.5

5.3

9.1

1.4

17.6

10.2

8.8

1 Persons of Hispanic origin may be of any race.

4
never married persons and the 18.8 percent for separated, divorced, or widowed persons. The same pattern

held also for persons who were poor for at least 2

months (table A) and for the chronically poor (table B).

Married persons who became poor during the 1990

panel also had significantly shorter median poverty

spells than persons who were separated, divorced, or

widowed, 3.8 versus 4.9 months (see table B).

As was the case with persons in married-couple

families, married persons were less likely to be poor in

an average month of 1990 than of 1987. At the same

time, there was a significant increase in never married

persons’ likelihood of being poor for at least 2 months

during the year. While 19.4 percent were poor 2 or more

months in 1987, 21.9 percent were so in 1990.

Race and Hispanic Origin5. There was a strong

correlation between race and Hispanic origin and poverty. Whites were significantly less likely to be poor than

persons who were Black or of Hispanic origin. Blacks

were almost three times as likely as Whites to be poor in

an average month, and persons of Hispanic origin had a

5

Persons of Hispanic origin may be of any race.

Table A. Poverty Status, by Family and Marital Status: 1991, 1990, and 1987

[In thousands. Bases for percentages can be found in the detailed tables]

Family and marital status

Persons poor in an average month Persons poor 2 or more months

1991 1990 1987 1991 1990 1987

Number Percent Number Percent Number Percent Number Percent Number Percent Number Percent

Total................... 33,866 13.6 31,818 12.9 31,980 13.3 48,477 19.8 45,638 18.9 44,811 19.1

Family Status

In families ................ 26,488 12.4 24,494 11.6 25,350 12.2 39,343 18.7 36,507 17.5 36,831 17.9

In married-couple

families .............. 12,624 7.4 11,852 7.0 13,211 7.9 22,682 13.3 21,509 12.7 21,666 13.0

In families with a

female householder, no spouse

present ............... 12,989 36.7 11,960 35.2 11,495 35.0 15,410 45.4 14,044 43.1 14,014 43.4

Unrelated individuals ...... 7,378 20.4 7,324 20.4 6,630 20.5 9,134 26.9 9,131 27.6 7,980 27.0

Marital Status (persons

18 years and over)

Married .................. 6,595 6.1 6,298 5.8 7,171 6.8 11,993 11.1 11,563 10.7 12,003 11.3

Separated, divorced, or

widowed ................ 6,665 19.4 6,404 18.8 6,508 20.1 8,476 26.3 8,067 25.3 8,523 28.0

Never married ............ 6,645 16.1 6,090 15.1 5,347 14.1 9,134 23.1 8,336 21.9 6,858 19.4

Table B. The Chronically Poor and Median Spell Durations, by Family and Marital Status:

1990 to 1991 and 1987 to 1988

[In thousands. Bases for percentages can be found in the detailed tables]

Family and marital status

Persons poor all 24 months of 2-year period Median duration

of poverty

spells in the

1990 panel

(in months)

1990-91 1987-88

Number Percent Number Percent

Total ......................................... 10,619 4.5 10,162 4.4 4.0

Family Status

In families ...................................... 8,031 3.9 7,975 3.9 4.0

In married-couple families ...................... 2,299 1.4 2,976 1.8 3.8

In families with a female householder,

no spouse present ............................ 5,571 17.6 4,872 15.6 6.5

Unrelated individuals ............................. 2,589 8.1 2,187 7.7 4.1

Marital Status (persons 18 years and over)

Married ......................................... 1,290 1.2 1,598 1.5 3.8

Separated, divorced, or widowed .................. 2,675 8.8 2,311 8.0 4.9

Never married ................................... 1,835 4.9 1,455 4.2 4.4

5
poverty rate intermediate between Whites and Blacks

(table C). The long-term poverty rate was 3.0 percent for

Whites, 10.4 percent for persons of Hispanic origin, and

13.9 percent for Blacks. While Whites were less likely

than others to be poor for 2 or more months during 1990,

there was no significant difference between Blacks and

persons of Hispanic origin.

Despite much higher poverty rates for Blacks and

persons of Hispanic origin, the majority of poor persons

were White, regardless of the measure used. Whites

constituted 66.7 percent of the poverty population in an

average month of 1990, 70.2 percent of those who were

poor 2 or more months during the year, and 56.2 percent

of the long-term poor.

Blacks and persons of Hispanic origin had significantly longer poverty spells than Whites, as can be seen

in table C and figure 4. While White persons experienced a median spell duration of 3.9 months, Blacks had

a median duration of 5.8 months and persons of Hispanic origin of 4.9 months (The Hispanic/Black difference was not statistically significant).

Age. Children were much more likely to be poor than

persons in other age groups. One in five children (20.1

percent) were poor in an average month of 1990,

compared to 10.5 percent of non-elderly adults and 9.4

percent of the elderly (see table D). Even more pronounced is the difference in long-term poverty between

children and non-elderly adults, 7.5 versus 3.0 percent.

Reflecting a tendency toward longer spells of poverty,

the elderly and children made up a larger fraction of the

long-term poor than of the average monthly poverty

population and of those who were poor 2 or more

months during the year. The elderly accounted for 13.2

percent of the long-term poor, but only 8.7 percent of

those who were poor in an average month. For children,

the corresponding fractions were 45.4 and 40.9 percent.

In contrast, non-elderly adults accounted for 41.4 percent of the long-term poor, but 50.3 percent of those who

were poor in an average month. As can be seen in table

D, of the 3.5 million elderly who were poor 2 or more

months during 1990, 1.4 million or 39.8 percent were

poor during the entire 2-year period. The respective

rates for children and non-elderly adults were 27.3 and

18.0 percent.

Median poverty spell durations during the 1990 panel

were 3.9 months for non-elderly adults, 4.4 months for

children, and 6.2 months for the elderly. However, these

duration differences were not statistically significant

(figure 4).

Education. There is a strong association between

poverty and education of persons 18 years and older.

Table E shows that 20.8 percent of persons without a

Figure 3.

Distribution of Poverty Spells, by Spell Length: 1990 to 1992

Percent

2-4 5-8 9-12

50

19

8

13-16 17-20

4

13

21-24 > 24

3 2

Months

6
high school diploma were poor in an average month of

1990, but only 9.3 percent of those with a high school

diploma, and 5.5 percent of those with 1 or more years

of college. This relationship also held for long-term

poverty and for poverty that lasted at least 2 months.

Persons without a high school diploma had significantly longer poverty spells than persons with a high

school diploma and persons with 1 or more years of

college, 5.3 versus 3.9 and 3.7 months respectively.

Median durations did not differ significantly between

those with a high school degree and those with 1 or

more years of college (table E and figure 4).

Employment Status. Unemployed persons were more

likely than other labor force groups to be poor. About

39.8 percent of the unemployed were poor in an average

month of 1990, followed by 11.6 percent of part-time

workers, and 3.7 percent of full-time workers. The

proportion of those not in the labor force who were poor

was intermediate between part-time workers and the

unemployed, 18.2 percent. Long-term poverty rates and

the percent of persons who were poor 2 months or more

varied likewise with employment status, as can be seen

in table E.6

There were significant differences in poverty spell

lengths between full-time workers and persons out of the

labor force. Full-time workers had a median spell duration of 3.6 months, compared to 5.0 months for persons

out of the labor force, as can be seen in table E and

figure 4.

Disability Status. As shown in table E, persons with a

work disability were much more likely to be poor than

others. While 9.0 percent of persons without a disability

were poor in an average month of 1990, 17.8 percent of

persons with a disability were poor. About 25.8 percent

of persons with a disability were poor at least 2 months

in 1990 and 7.3 percent were poor in all months of 1990

and 1991. The respective poverty rates for persons

without a disability were 14.4 and 2.3 percent.

Disability status did not significantly affect the length

of poverty spells. Half of the spells experienced by the

disabled lasted longer than 4.9 months, compared to 3.9

months for persons who were not disabled.

Residence. Residents of non-metropolitan areas were

more likely to be poor than metropolitan residents.

However, central city residents did not differ from nonmetropolitan residents in their likelihood of being poor in

an average month or at least 2 months (see table F).

Central city residents were, however, more likely than

non-metropolitan residents to be permanently poor, 7.2

versus 5.3 percent. Persons who live in the suburbs had

the lowest poverty rates of any group. For instance,the

average monthly poverty rate of suburban residents was

8.0 percent, followed by 11.8 percent of metropolitan

residents as a whole, 16.4 percent of persons in nonmetropolitan areas, and 17.6 percent of central city

residents.

Metropolitan residents in general and suburban residents specifically had much shorter median spell durations than their counterparts outside metropolitan areas,

3.9, 3.8, and 4.7 months, respectively as can be seen in

figure 4.

Region. Southern residents had a higher likelihood of

living in poverty than persons in other regions. Table F

shows that their average monthly poverty rate was 15.9

percent in 1990, compared to 11.9 percent for the

Midwest, 11.6 percent for the West, and 10.2 percent for

the Northeast. Average monthly poverty rates of Midwestern and Western residents were not significantly

different. The Northeast had the lowest average monthly

poverty rates and the smallest percentage of persons

who were poor for at least 2 months. The West, however, had the smallest long-term poverty rate, 2.9 percent, compared to 4.2 percent for the Northeast, 4.3

percent for the Midwest, and 5.7 percent for the South.

The long-term poverty rates for the Northeast and

Midwest were not statistically different.

There were no significant differences in poverty spell

lengths by region. Point estimates of median durations

ranged between 3.8 months for Northeastern residents

and 4.4 months for Southern residents.

6

The unemployed were not significantly more likely than persons

out of the labor force to be poor all 24 months.

Table C. Poverty Status, by Race and Hispanic Origin: 1990

[In thousands. Bases for percentages can be found in the detailed tables]

Race and Hispanic origin

Persons poor in an

average month

Persons poor 2

or more months

Persons poor all 24

months of 1990-91

Median duration

of poverty

spells in the

1990 panel

Number Percent Number Percent Number Percent (in months)

Total .............................. 31,818 12.9 45,638 18.9 10,619 4.5 4.0

White................................ 21,233 10.2 32,042 15.7 5,969 3.0 3.9

Black ................................ 9,152 30.1 11,621 39.2 4,060 13.9 5.8

Hispanic origin1....................... 5,465 26.1 7,345 37.5 1,949 10.4 4.9

1

Persons of Hispanic origin may be of any race.

7
Figure 4.

Median Durations of Poverty Spells, by

Various Characteristics: 1990 to 1992

Percent

All persons

White

Black

Hispanic origin1

Metropolitan

Not in labor force

Less than 4 years

of high school

Persons in marriedcouple families

Persons in femalehouseholder families

Unemployed

High school graduate,

no college

4.0

3.9

5.8

4.9

3.8

6.5

4.1

5.3

3.9

3.7

3.6

4.0

4.3

5.0

3.9

4.1

3.8

4.7

Unrelated individuals

One or more

years of college

Employed full-time

Employed part-time

Central city

Non-central city

Nonmetropolitan

1 Persons of Hispanic origin may be of any race.

Table D. Poverty Status, by Age: 1990

[In thousands. Bases for percentages can be found in the detailed tables]

Age

Persons poor in an

average month

Persons poor 2

or more months

Persons poor all 24

months of 1990-91

Number Percent Number Percent Number Percent

Total.................................... 31,818 12.9 45,638 18.9 10,619 4.5

Under 18 years ............................ 13,027 20.1 17,672 27.7 4,820 7.5

18 to 64 years ............................. 16,009 10.5 24,454 16.4 4,401 3.0

65 years and over .......................... 2,783 9.4 3,512 12.5 1,399 5.3

8
Annual Measures of Poverty

While year-to-year changes in the total number and

percent of persons in poverty are, in general, relatively

small, the poverty population is actually much more

dynamic than is commonly thought. In fact, many more

people change poverty status from one year to the next

than are indicated by simply looking at the net change in

the poverty rate.

SIPP annual poverty estimates can be obtained by

summing monthly family income over the year and

comparing it to the sum of the 12 corresponding monthly

thresholds, based on family size and composition in

each month. Based on persons interviewed over the

2-year period, 18.8 million persons who were poor in

1990 remained poor in 1991. In addition, there was a 1.1

million increase in the number of persons in poverty

between 1990 and 1991.7 This increase, however, may

more accurately be viewed as the net result of the

poverty transitions experienced by 11.3 million persons,

7

The number of poor persons as measured by the CPS was 33.5

million in 1990 and 35.7 million in 1991. This increase was much

larger than the one measured by the SIPP over the same time

period.

Table E. Poverty Status, by Education, Employment, and Disability Status: 1990

[In thousands. Bases for percentages can be found in the detailed tables]

Characteristic

Persons poor in an

average month

Persons poor 2

or more months

Persons poor all 24

months of 1990-91

Median duration

of poverty

spells in the

1990 panel

Number Percent Number Percent Number Percent (in months)

Total .............................. 31,818 12.9 45,638 18.9 10,619 4.5 4.0

Educational Attainment (persons

18 years and over)

Less than 4 years of high school ....... 8,392 20.8 11,229 29.2 3,366 9.1 5.3

High school graduate, no college ....... 6,350 9.3 9,927 14.6 1,776 2.7 3.9

1 or more years of college ............. 4,050 5.5 6,809 9.6 658 0.9 3.7

Employment and Labor Force Status

(persons 18 years and over)

Employed full-time .................... 3,544 3.7 8,712 9.2 392 0.4 3.6

Employed part-time ................... 2,407 11.6 4,098 19.5 465 2.2 4.0

Unemployed ......................... 2,048 39.8 2,494 46.9 502 10.2 4.3

Not in labor force ..................... 10,793 18.2 12,662 22.5 4,441 8.3 5.0

Disability Status (persons 15 to

69 years)

With a work disability.................. 5,304 17.8 7,149 25.8 1,899 7.3 4.9

With no work disability................. 12,944 9.0 20,378 14.4 3,239 2.3 3.9

Table F. Poverty Status, by Residence and Region: 1990

[In thousands. Bases for percentages can be found in the detailed tables]

Residence and region

Persons poor in an

average month

Persons poor 2

or more months

Persons poor all 24

months of 1990-91

Median duration

of poverty

spells in the

1990 panel

Number Percent Number Percent Number Percent (in months)

Total .............................. 31,818 12.9 45,638 18.9 10,619 4.5 4.0

Residence

Metropolitan.......................... 22,444 11.8 32,036 17.4 7,593 4.2 3.9

Central city......................... 13,309 17.6 17,194 24.2 4,947 7.2 4.1

Non-central city..................... 9,135 8.0 14,841 13.1 2,645 2.4 3.8

Nonmetropolitan ...................... 9,374 16.4 13,602 23.9 3,027 5.3 4.7

Region

Northeast ............................ 5,139 10.2 6,980 14.4 2,007 4.2 3.8

Midwest ............................. 7,345 11.9 10,472 16.9 2,689 4.3 3.9

South ............................... 13,458 15.9 19,606 23.8 4,570 5.7 4.4

West ................................ 5,876 11.6 8,579 17.7 1,354 2.9 4.2

9
as 5.1 million moved out of poverty and 6.2 million

persons moved into poverty, representing 21.2 and 2.9

percent of the respective populations.

Exit rates in table G reveal much the same picture as

the previous section. Characteristics associated with

shorter median spell durations are also associated with

higher exit rates. For instance, persons in marriedcouple families were much more likely to exit poverty

than persons in other type families, 28.6 versus 12.2

percent, consistent with their significantly shorter poverty duration. Likewise, Blacks were less likely than

Whites to exit poverty, and children and the elderly,

although comparable to one another, were less likely

than non-elderly adults to exit poverty.

The years 1987 and 1988 were a period of economic

upswing, while 1990 and 1991 were recession years.

Thus, one would expect a higher probability of becoming

poor and a lower probability of leaving poverty behind in

the 1990-91 period than in 1987-88. Table G shows a

greater probability of becoming poor in the recessionary

period of 1990-1991 and a lower probability of leaving

poverty compared with the 1987-88 period during which

only 2.2 percent became poor while one-fourth of the

poverty population became nonpoor.

In addition to examining changes in poverty, SIPP

also allows us to characterize long-term poverty. Comparing an annual measure to a monthly measure, two

types of long-term poverty can be described. Using an

annual measure of poverty, about 19 million persons

who were poor in 1990 were also poor in 1991, as can

be seen in table H. Using a monthly measure of poverty,

in the previous section, resulted in a smaller estimate of

the long-term poor, 10.6 million. In order to be counted

as ‘‘chronically’’ poor in the previous section, a person

had to be poor in each of the 24 months of 1990 and

1991. To be counted as long-term poor on an annual

basis, persons had to meet a less stringent requirement:

the average income had to fall below the average

monthly threshold for 2 years in a row. As a result,

long-term poverty rates were higher based on the annual

measure than based on the monthly measure.

The profile of the long-term poor differed in some

instances, depending on which measure was used. This

difference reflects the more chronic nature of poverty

experienced by some groups. As can be seen in table H,

while Blacks made up 34.4 percent of the long-term poor

based on an annual measure, they made up a higher

38.2 percent of the chronically poor. Likewise, the

elderly, who generally experience only minor fluctuations in income, represented a significantly larger

portion of the chronically poor than of those poor 2

years in a row, 13.2 versus 10.2 percent. Persons in

Table G. Percent of Persons Entering and Exiting Poverty: 1990 to 1991 and 1987 to 1988

[In thousands. Bases for percentages can be found in the detailed tables]

Characteristic

Above

poverty in

1990

Entered

poverty in

1991

Above

poverty in

1987

Entered

poverty in

1988

Below

poverty in

1990

Exited

poverty in

1991

Below

poverty in

1987

Exited

poverty in

1988

Total ............................ 211,962 2.9 206,068 2.2 23,849 21.2 24,922 25.7

Race and Hispanic Origin

White ............................. 183,754 2.5 180,270 1.9 14,826 23.3 15,363 30.0

Black ............................. 21,152 6.5 19,405 5.3 7,829 17.4 8,402 17.0

Hispanic origin1 .................... 14,627 8.3 13,461 4.1 3,938 14.3 3,982 18.1

Age

Under 18 years .................... 50,549 4.3 49,028 3.3 10,183 19.0 10,544 22.9

18 to 64 years ..................... 136,229 2.6 132,784 2.0 11,440 24.5 12,007 30.0

65 years and over .................. 25,185 1.7 24,256 1.3 2,226 14.2 2,371 16.2

Family Status

In married-couple families both

years ............................ 154,532 1.9 151,562 1.3 8,007 28.6 9,586 31.0

In other family types both years ...... 23,222 5.9 22,986 5.8 9,886 12.2 9,391 18.6

1

Persons of Hispanic origin may be of any race.

10
family types other than married-couple made up a

significantly larger portion of the chronically poor than of

those poor 2 years, 54.0 versus 46.2 percent, respectively. On the other hand, persons in married-couple

families accounted for 30.4 percent of those poor for 2

years, but only 21.7 percent of those who were chronically poor. These differences in distribution in the different poverty populations attest to differences in intensity

and permanency of poverty of some groups relative to

others.

Table H. Profile of the Long-Term Poor: 1990 to 1991

[In thousands]

Characteristic

Annual measure1 Monthly measure2

Number

Percent

distributiion Number

Percent

distribution

Total .................................................. 18,797 100.0 10,619 100.0

Race and Hispanic Origin

White ................................................. 11,368 60.5 5,969 56.2

Black.................................................. 6,471 34.4 4,060 38.2

Hispanic origin3 ........................................ 3,374 17.9 1,949 18.4

Age

Under 18 years......................................... 8,248 43.9 4,820 45.4

18 to 64 years ......................................... 8,641 46.0 4,401 41.4

65 years and over ...................................... 1,909 10.2 1,399 13.2

Family Status

In married-couple families both years ..................... 5,715 30.4 2,299 21.7

In other family types both years .......................... 8,679 46.2 5,732 54.0

1

Requires persons’ average income to fall below the average monthly threshold in 1990 and in 1991.

2

Requires persons to be poor in each of the 24 months of 1990 and 1991.

3

Persons of Hispanic origin may be of any race.

11
Table 1. Average Monthly Poverty, by Selected Characteristics: 1990 and 1991

[Numbers in thousands]

Characteristic

1990 1991

Total

Poor

Total

Poor

Number Percent Number Percent

All persons .............................. 247,175 31,818 12.9 249,775 33,866 13.6

Race and Hispanic Origin

White ..................................... 208,336 21,233 10.2 210,266 22,864 10.9

Not of Hispanic origin1 .................... 190,472 16,672 8.8 191,574 17,677 9.2

Black ..................................... 30,401 9,152 30.1 30,813 9,472 30.7

Hispanic origin ............................. 20,964 5,465 26.1 21,787 6,161 28.3

Not of Hispanic origin ....................... 226,211 26,353 11.6 227,988 27,705 12.2

Age

Under 18 years ............................ 64,866 13,027 20.1 65,712 13,961 21.2

18 to 64 years ............................. 152,633 16,009 10.5 153,924 17,121 11.1

65 years and over .......................... 29,676 2,783 9.4 30,139 2,783 9.2

Sex

Male ...................................... 120,334 13,343 11.1 121,696 14,587 12.0

Female.................................... 126,841 18,476 14.6 128,079 19,279 15.1

Educational Attainment (persons 18 years

and over)

Less than 4 years of high school ............. 40,444 8,392 20.8 40,426 8,618 21.3

High school graduate, no college............. 68,575 6,350 9.3 68,867 6,923 10.1

1 or more years of college................... 73,290 4,050 5.5 74,770 4,364 5.8

Disability Status (persons 15 to 69 years)

With a work disability ....................... 29,766 5,304 17.8 29,316 5,407 18.4

With no work disability ...................... 143,067 12,944 9.0 144,681 14,144 9.8

Residence

Metropolitan ............................... 190,166 22,444 11.8 191,052 24,039 12.6

Central city .............................. 75,586 13,309 17.6 78,651 14,503 18.4

Non-central city .......................... 114,580 9,135 8.0 112,401 9,537 8.5

Nonmetropolitan............................ 57,009 9,374 16.4 58,723 9,826 16.7

Region

Northeast.................................. 50,271 5,139 10.2 50,210 5,675 11.3

Midwest ................................... 61,772 7,345 11.9 63,262 8,084 12.8

South ..................................... 84,387 13,458 15.9 84,554 13,687 16.2

West...................................... 50,745 5,876 11.6 51,748 6,420 12.4

Family Status

In families ................................. 211,306 24,494 11.6 213,689 26,488 12.4

In families with related children under

18 years ............................... 135,778 21,747 16.0 137,277 23,545 17.2

In married-couple families ................. 170,324 11,852 7.0 171,218 12,624 7.4

In married-couple families with related

children under 18 years ................ 106,788 9,959 9.3 107,053 10,708 10.0

In families with a female householder,

no spouse present ...................... 33,959 11,960 35.2 35,415 12,989 36.7

In families with a female householder

no spouse present, with related children

under 18 years........................ 25,354 11,277 44.5 26,623 12,229 45.9

Unrelated individuals........................ 35,869 7,324 20.4 36,085 7,378 20.4

In non-family households .................. 33,065 6,317 19.1 33,420 6,347 19.0

See footnotes at end of table.

13
Table 1. Average Monthly Poverty, by Selected Characteristics: 1990 and 1991—Continued

[Numbers in thousands]

Characteristic

1990 1991

Total

Poor

Total

Poor

Number Percent Number Percent

Employment and Labor Force Status

(persons 18 years and over)

Employed full-time.......................... 97,094 3,544 3.7 95,567 3,532 3.7

Employed part-time......................... 20,731 2,407 11.6 21,709 2,520 11.6

Unemployed ............................... 5,148 2,048 39.8 6,344 2,483 39.1

Not in labor force........................... 59,333 10,793 18.2 60,442 11,370 18.8

Marital Status (persons 18 years and over)

Married ................................... 107,843 6,298 5.8 108,371 6,595 6.1

Separated, divorced, or widowed............. 34,092 6,404 18.8 34,361 6,665 19.4

Never married ............................. 40,374 6,090 15.1 41,331 6,645 16.1

Family Size

1 person (unrelated individual) ............... 35,863 7,319 20.4 36,077 7,376 20.4

2 persons ................................. 57,023 4,703 8.2 57,165 4,857 8.5

3 persons ................................. 47,172 4,804 10.2 48,160 5,445 11.3

4 persons ................................. 55,865 5,779 10.3 56,761 6,002 10.6

5 persons ................................. 30,164 4,226 14.0 30,363 4,632 15.3

6 or more persons.......................... 21,089 4,986 23.6 21,248 5,553 26.1

Access to Health Insurance

Covered by health insurance ................ 215,277 21,695 10.1 217,614 23,625 10.9

Private insurance......................... 191,564 8,892 4.6 192,021 9,227 4.8

Medicare ................................ 32,127 3,261 10.2 32,576 3,288 10.1

Medicaid ................................ 19,110 12,364 64.7 21,379 13,971 65.4

Not covered by health insurance ............. 31,898 10,123 31.7 32,161 10,241 31.8

Receipt of Public Assistance

Received public assistance2 ................. 28,461 16,805 59.0 30,859 18,463 59.8

Did not receive public assistance............. 218,713 15,013 6.9 218,916 15,403 7.0

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

14
Table 2. Persons Poor 2 or More Months, by Selected Characteristics: 1990 and 1991

[Numbers in thousands]

Characteristic

1990 panel 1990 1991

Total

Persons ever poor

over the panel

Total

Persons ever poor

during the year

Total

Persons ever poor

during the year

Number Percent Number Percent Number Percent

All persons.......................... 235,811 62,414 26.5 241,534 45,638 18.9 244,658 48,477 19.8

Race and Hispanic Origin

White................................... 198,579 45,854 23.1 203,507 32,042 15.7 205,468 34,359 16.7

Not of Hispanic origin1 ................ 182,646 38,160 20.9 186,770 25,780 13.8 187,679 27,175 14.5

Black ................................... 28,982 13,983 48.2 29,672 11,621 39.2 30,342 11,947 39.4

Hispanic origin .......................... 18,565 9,088 49.0 19,565 7,345 37.5 20,756 8,431 40.6

Not of Hispanic origin .................... 217,246 53,325 24.5 221,969 38,293 17.3 223,901 40,046 17.9

Age

Under 18 years .......................... 63,995 23,471 36.7 63,902 17,672 27.7 64,765 18,874 29.1

18 to 64 years........................... 146,555 34,904 23.8 149,553 24,454 16.4 151,137 26,014 17.2

65 years and over ....................... 25,261 4,038 16.0 28,078 3,512 12.5 28,755 3,589 12.5

Sex

Male ................................... 113,681 27,848 24.5 117,064 19,714 16.8 118,795 21,514 18.1

Female ................................. 122,131 34,566 28.3 124,470 25,924 20.8 125,862 26,963 21.4

Educational Attainment (persons 18 years

and over)

Less than 4 years of high school .......... 35,816 13,400 37.4 38,443 11,229 29.2 39,065 11,454 29.3

High school graduate, no college .......... 66,284 14,704 22.2 67,986 9,927 14.6 67,285 10,773 16.0

1 or more years of college ................ 69,716 10,838 15.5 71,203 6,809 9.6 73,542 7,376 10.0

Disability Status (persons 15 to 69 years)

With a work disability..................... 25,567 8,698 34.0 27,688 7,149 25.8 26,471 7,094 26.8

With no work disability.................... 140,149 30,392 21.7 141,611 20,378 14.4 144,425 22,302 15.4

Residence

Metropolitan............................. 179,368 43,837 24.4 184,601 32,036 17.4 186,601 33,943 18.2

Central city............................ 68,170 21,815 32.0 71,093 17,194 24.2 74,670 18,902 25.3

Non-central city........................ 111,198 22,022 19.8 113,508 14,841 13.1 111,931 15,041 13.4

Nonmetropolitan ......................... 56,444 18,577 32.9 56,933 13,602 23.9 58,057 14,534 25.0

Region

Northeast ............................... 47,959 10,328 21.5 48,416 6,980 14.4 49,466 8,131 16.4

Midwest ................................ 62,050 15,253 24.6 62,106 10,472 16.9 63,105 11,611 18.4

South .................................. 79,006 25,459 32.2 82,439 19,606 23.8 82,151 19,484 23.7

West ................................... 46,795 11,373 24.3 48,573 8,579 17.7 49,937 9,250 18.5

Family Status

In families............................... 204,127 51,522 25.2 208,505 36,507 17.5 210,751 39,343 18.7

In families with related children under

18 years ............................. 134,944 42,933 31.8 135,441 31,453 23.2 136,496 33,619 24.6

In married-couple families............... 167,119 33,665 20.1 169,821 21,509 12.7 170,924 22,682 13.3

In married-couple families with

related children under 18 years....... 107,945 27,328 25.3 107,680 17,775 16.5 107,809 18,684 17.3

In families with a female householder,

no spouse present .................... 31,436 16,285 51.8 32,546 14,044 43.1 33,926 15,410 45.4

In families with a female householder,

no spouse present, with related

children under 18 years ............. 24,026 14,530 60.5 24,486 12,981 53.0 25,591 14,113 55.1

Unrelated individuals ..................... 31,684 10,892 34.4 33,029 9,131 27.6 33,906 9,134 26.9

In non-family households ............... 29,691 9,793 33.0 30,699 8,099 26.4 31,490 8,033 25.5

See footnotes at end of table.

15
Table 2. Persons Poor 2 or More Months, by Selected Characteristics: 1990 and 1991—Continued

[Numbers in thousands]

Characteristic

1990 panel 1990 1991

Total

Persons ever poor

over the panel

Total

Persons ever poor

during the year

Total

Persons ever poor

during the year

Number Percent Number Percent Number Percent

Employment and Labor Force Status

(persons 18 years and over)

Employed full-time ....................... 94,159 15,197 16.1 95,043 8,712 9.2 94,596 8,831 9.3

Employed part-time ...................... 20,055 5,500 27.4 20,967 4,098 19.5 22,743 4,430 19.5

Unemployed ............................ 4,874 2,925 60.0 5,314 2,494 46.9 5,385 2,737 50.8

Not in labor force ........................ 52,727 15,319 29.1 56,309 12,662 22.5 57,168 13,605 23.8

Marital Status (persons 18 years

and over)

Married ................................. 105,375 17,954 17.0 107,732 11,563 10.7 108,031 11,993 11.1

Separated, divorced, or widowed .......... 29,999 9,640 32.1 31,865 8,067 25.3 32,242 8,476 26.3

Never married ........................... 36,441 11,348 31.1 38,035 8,336 21.9 39,620 9,134 23.1

Family Size

1 person (unrelated individual) ............ 31,684 10,892 34.4 33,024 9,125 27.6 33,906 9,134 26.9

2 persons ............................... 53,640 9,575 17.9 56,119 6,986 12.4 56,179 7,080 12.6

3 persons ............................... 44,879 10,427 23.2 46,104 7,260 15.7 47,197 8,144 17.3

4 persons ............................... 56,052 12,689 22.6 56,055 8,622 15.4 56,500 9,244 16.4

5 persons ............................... 29,634 9,506 32.1 29,747 6,293 21.2 30,284 6,877 22.7

6 or more persons ....................... 19,922 9,325 46.8 20,487 7,352 35.9 20,590 7,999 38.8

Access to Health Insurance

Covered by health insurance .............. 206,997 44,530 21.5 210,838 31,333 14.9 214,314 34,042 15.9

Private insurance ...................... 186,507 30,293 16.2 188,731 17,671 9.4 190,018 18,274 9.6

Medicare ............................. 27,696 4,686 16.9 30,278 4,081 13.5 31,247 4,193 13.4

Medicaid.............................. 16,456 13,425 81.6 17,252 12,948 75.0 19,794 15,026 75.9

Not covered by health insurance........... 28,815 17,884 62.1 30,696 14,305 46.6 30,344 14,435 47.6

Receipt of Public Assistance

Received public assistance2

............... 25,933 20,308 78.3 27,149 19,015 70.0 28,889 20,826 72.1

Did not receive public assistance .......... 209,878 42,106 20.1 214,386 26,623 12.4 215,769 27,651 12.8

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

16
Table 3. Persons Poor Each Month of 1990 and 1991, by Selected Characteristics

[Numbers in thousands]

Characteristic

Total

Persons poor entire 24 months

Number Percent

All persons.................................................... 237,417 10,619 4.5

Race and Hispanic Origin

White........................................................... 199,844 5,969 3.0

Not of Hispanic origin1 ........................................ 183,702 4,343 2.4

Black ........................................................... 29,147 4,060 13.9

Hispanic origin .................................................. 18,791 1,949 10.4

Not of Hispanic origin ............................................ 218,625 8,671 4.0

Age

Under 18 years .................................................. 63,838 4,820 7.5

18 to 64 years................................................... 147,355 4,401 3.0

65 years and over ............................................... 26,224 1,399 5.3

Sex

Male ........................................................... 114,607 3,771 3.3

Female ......................................................... 122,809 6,848 5.6

Educational Attainment (persons 18 years and over)

Less than 4 years of high school .................................. 36,792 3,366 9.1

High school graduate, no college .................................. 66,802 1,776 2.7

1 or more years of college ........................................ 69,985 658 0.9

Disability Status (persons 15 to 69 years)

With a work disability............................................. 25,940 1,899 7.3

With no work disability............................................ 140,774 3,239 2.3

Residence

Metropolitan..................................................... 180,493 7,593 4.2

Central city.................................................... 68,676 4,947 7.2

Non-central city................................................ 111,818 2,645 2.4

Nonmetropolitan ................................................. 56,923 3,027 5.3

Region

Northeast ....................................................... 48,202 2,007 4.2

Midwest ........................................................ 62,423 2,689 4.3

South .......................................................... 79,624 4,570 5.7

West ........................................................... 47,167 1,354 2.9

Family Status

In families....................................................... 205,379 8,031 3.9

In families with related children under 18 years.................... 135,060 7,450 5.5

In married-couple families....................................... 168,147 2,299 1.4

In married-couple families with related children under 18 years.... 108,115 1,905 1.8

In families with a female householder, no spouse present .......... 31,589 5,571 17.6

In families with a female householder, no spouse present,

with related children under 18 years .......................... 23,972 5,427 22.6

Unrelated individuals ............................................. 32,037 2,589 8.1

In non-family households ....................................... 30,033 2,341 7.8

Employment and Labor Force Status (persons 18 years and over)

Employed full-time ............................................... 94,597 392 0.4

Employed part-time .............................................. 20,725 465 2.2

Unemployed .................................................... 4,920 502 10.2

Not in labor force ................................................ 53,337 4,441 8.3

See footnotes at end of table.

17
Table 3. Persons Poor Each Month of 1990 and 1991, by Selected Characteristics—Continued

[Numbers in thousands]

Characteristic

Total

Persons poor entire 24 months

Number Percent

Marital Status (person 18 years and over)

Married ......................................................... 106,079 1,290 1.2

Separated, divorced, or widowed .................................. 30,428 2,675 8.8

Never married ................................................... 37,072 1,835 4.9

Family Size

1 person (unrelated individual) .................................... 32,037 2,589 8.1

2 persons ....................................................... 54,131 1,542 2.8

3 persons ....................................................... 45,131 1,625 3.6

4 persons ....................................................... 56,209 1,799 3.2

5 persons ....................................................... 29,882 1,411 4.7

6 or more persons ............................................... 20,026 1,654 8.3

Access to Health Insurance

Covered by health insurance ...................................... 208,669 8,248 4.0

Private insurance .............................................. 187,583 1,267 0.7

Medicare ..................................................... 28,467 1,626 5.7

Medicaid...................................................... 16,789 6,622 39.4

Not covered by health insurance................................... 28,747 2,372 8.2

Receipt of Public Assistance

Received public assistance2

....................................... 26,539 8,380 31.6

Did not receive public assistance .................................. 210,878 2,239 1.1

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

18
Table 4. Spells of Poverty for Persons Who Became Poor During the 1990 SIPP Panel, by Selected

Characteristics

[Numbers in thousands]

Characteristic

Total

spells

Percentage

of spells

rightcensored

Survival rates of poverty spells after--

Median

spell

duration

1

month

4

months

8

months

12

months

16

months

20

months

24

months

28

months

All persons .................... 62,574 26.9 1.0000 0.5023 0.3091 0.2263 0.1828 0.1543 0.1299 0.1208 4.0

Race and Hispanic Origin

White ........................... 48,763 25.3 1.0000 0.4885 0.2851 0.2054 0.1623 0.1387 0.1201 (B) 3.9

Not of Hispanic origin1 .......... 40,440 24.7 1.0000 0.4737 0.2680 0.1908 0.1509 0.1281 0.1113 (B) 3.9

Black ........................... 11,715 33.3 1.0000 0.5532 0.3975 0.2990 0.2594 0.2043 0.1756 (B) 5.8

Hispanic origin ................... 9,557 28.2 1.0000 0.5662 0.3596 0.2658 0.2120 0.1836 (B) (B) 4.9

Not of Hispanic origin ............. 53,017 26.7 1.0000 0.4904 0.2995 0.2188 0.1773 0.1489 0.1243 0.1144 4.0

Age

Under 18 years .................. 21,148 27.5 1.0000 0.5223 0.3217 0.2448 0.2075 0.1746 0.1456 (B) 4.4

18 to 64 years ................... 38,134 25.9 1.0000 0.4844 0.2948 0.2104 0.1636 0.1365 0.1137 (B) 3.9

65 years and over ................ 3,292 34.9 1.0000 0.5790 0.3913 0.2852 0.2367 0.2224 (B) (B) 6.2

Sex

Male ............................ 29,655 25.5 1.0000 0.4864 0.2907 0.2112 0.1677 0.1409 0.1200 (B) 3.9

Female.......................... 32,919 28.2 1.0000 0.5167 0.3257 0.2399 0.1965 0.1664 0.1389 (B) 4.3

Educational Attainment (persons

18 years and over)

Less than 4 years of high school . . . 12,816 32.2 1.0000 0.5625 0.3768 0.2904 0.2318 0.1968 0.1729 (B) 5.3

High school graduate, no college. . . 16,089 26.0 1.0000 0.4797 0.2891 0.2120 0.1649 0.1332 0.1199 (B) 3.9

1 or more years of college......... 12,522 21.7 1.0000 0.4347 0.2420 0.1447 0.1103 0.1012 (B) (B) 3.7

Disability Status (persons 15 to

69 years)

With a work disability ............. 8,162 30.4 1.0000 0.5382 0.3734 0.2893 0.2327 0.1905 0.1632 (B) 4.9

With no work disability ............ 34,110 25.0 1.0000 0.4779 0.2822 0.1955 0.1495 0.1246 0.1025 (B) 3.9

Residence

Metropolitan ..................... 43,135 26.5 1.0000 0.4868 0.3034 0.2197 0.1751 0.1499 0.1226 (B) 3.9

Central city .................... 21,825 29.4 1.0000 0.5029 0.3335 0.2514 0.2022 0.1716 0.1585 (B) 4.1

Non-central city ................ 21,310 23.6 1.0000 0.4706 0.2731 0.1875 0.1472 0.1281 0.0805 (B) 3.8

Nonmetropolitan.................. 19,439 27.8 1.0000 0.5365 0.3218 0.2406 0.1997 0.1639 0.1460 (B) 4.7

Region

Northeast........................ 9,738 25.7 1.0000 0.4552 0.2612 0.2119 0.1759 0.1534 (B) (B) 3.8

Midwest ......................... 15,376 27.0 1.0000 0.4886 0.3064 0.2184 0.1771 0.1390 0.1192 (B) 3.9

South ........................... 24,963 28.3 1.0000 0.5233 0.3321 0.2365 0.1916 0.1565 0.1284 (B) 4.4

West............................ 12,496 25.0 1.0000 0.5136 0.3047 0.2268 0.1772 0.1674 0.1304 (B) 4.2

Family Status

In families ....................... 50,714 26.5 1.0000 0.5011 0.3039 0.2237 0.1813 0.1518 0.1264 0.1209 4.0

In families with related children

under 18 years................ 42,231 27.1 1.0000 0.5090 0.3111 0.2353 0.1943 0.1612 0.1331 0.1283 4.2

In married-couple families ....... 35,600 22.8 1.0000 0.4605 0.2592 0.1859 0.1433 0.1140 0.0876 (B) 3.8

In married-couple families

with related children under

18 years ................... 29,247 23.3 1.0000 0.4658 0.2616 0.1954 0.1549 0.1210 0.0918 (B) 3.8

In families with a female householder, no spouse present...... 13,627 36.3 1.0000 0.6042 0.4219 0.3265 0.2858 0.2533 0.2318 (B) 6.5

In families with a female

householder, no spouse

present, with related children

under 18 years.............. 11,892 36.8 1.0000 0.6145 0.4371 0.3379 0.2977 0.2630 0.2388 (B) 6.8

Unrelated individuals.............. 11,860 28.8 1.0000 0.5073 0.3316 0.2377 0.1886 0.1657 (B) (B) 4.1

In non-family households ........ 10,737 29.0 1.0000 0.5088 0.3364 0.2396 0.1869 0.1696 (B) (B) 4.2

See footnotes at end of table.

19
Table 4. Spells of Poverty for Persons Who Became Poor During the 1990 SIPP Panel, by Selected

Characteristics—Continued

[Numbers in thousands]

Characteristic

Total

spells

Percentage

of spells

rightcensored

Survival rates of poverty spells after--

Median

spell

duration

1

month

4

months

8

months

12

months

16

months

20

months

24

months

28

months

Employment and Labor Force

Status (persons 18 years and

over)

Employed full-time................ 14,022 23.8 1.0000 0.4194 0.2518 0.1822 0.1452 0.1207 0.0930 (B) 3.6

Employed part-time............... 6,829 22.4 1.0000 0.5016 0.2728 0.1759 0.1262 0.1027 (B) (B) 4.0

Unemployed ..................... 5,548 26.9 1.0000 0.5209 0.3114 0.2115 0.1727 0.1379 (B) (B) 4.3

Not in labor force................. 15,027 31.1 1.0000 0.5447 0.3597 0.2686 0.2107 0.1849 0.1692 (B) 5.0

Marital Status (persons 18 years

and over)

Married ......................... 20,096 22.9 1.0000 0.4490 0.2533 0.1783 0.1326 0.1055 0.0814 (B) 3.8

Separated, divorced, or widowed. . . 9,597 33.6 1.0000 0.5439 0.3750 0.2831 0.2346 0.2101 0.1897 (B) 4.9

Never married ................... 11,734 27.3 1.0000 0.5231 0.3278 0.2276 0.1795 0.1539 0.1374 (B) 4.4

Family Size

1 person (unrelated individual) ..... 11,860 28.8 1.0000 0.5073 0.3316 0.2377 0.1886 0.1657 (B) (B) 4.1

2 persons ....................... 9,389 27.7 1.0000 0.5035 0.3160 0.2238 0.1785 0.1577 0.1441 (B) 4.1

3 persons ....................... 9,698 25.6 1.0000 0.5032 0.2998 0.2111 0.1622 0.1319 (B) (B) 4.1

4 persons ....................... 13,035 23.9 1.0000 0.4569 0.2679 0.1979 0.1548 0.1250 0.1085 (B) 3.7

5 persons ....................... 9,522 27.6 1.0000 0.4938 0.3109 0.2518 0.1856 0.1561 (B) (B) 4.0

6 or more persons................ 9,070 28.8 1.0000 0.5680 0.3413 0.2465 0.2377 0.2020 0.1572 (B) 4.9

Access to Health Insurance

Covered by health insurance ...... 40,201 26.4 1.0000 0.4868 0.2957 0.2155 0.1818 0.1548 0.1340 (B) 3.9

Private insurance............... 30,544 20.6 1.0000 0.4228 0.2284 0.1514 0.1175 0.0918 0.0713 (B) 3.6

Medicare ...................... 3,811 37.3 1.0000 0.5868 0.4223 0.3168 0.2688 0.2541 (B) (B) 6.9

Medicaid ...................... 9,307 46.0 1.0000 0.6960 0.5220 0.4337 0.4003 0.3635 0.3463 (B) 8.7

Not covered by health insurance . . . 22,373 27.8 1.0000 0.5302 0.3331 0.2459 0.1838 0.1524 0.1221 (B) 4.6

Receipt of Public Assistance

Received public assistance2 ....... 15,674 40.2 1.0000 0.6536 0.4646 0.3781 0.3332 0.2924 0.2734 (B) 7.1

Did not receive public assistance. . . 46,900 22.5 1.0000 0.4513 0.2560 0.1742 0.1317 0.1076 0.0835 (B) 3.8

B Base less than 200,000.

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

20
Table 5. Transitions Into and Out of Poverty, by Selected Characteristics: 1990 to 1991

[Numbers in thousands]

Poverty status in 1990

Total

Poverty status in 1991

Poor Nonpoor

All persons

Total ......................................................... 235,811 24,998 210,814

Poor ......................................................... 23,849 18,797 5,052

Nonpoor ...................................................... 211,962 6,201 205,761

Race and Hispanic Origin

White

Total ......................................................... 198,579 15,996 182,583

Poor ......................................................... 14,826 11,368 3,458

Nonpoor ...................................................... 183,754 4,628 179,125

Black

Total ......................................................... 28,982 7,854 21,128

Poor ......................................................... 7,829 6,471 1,359

Nonpoor ...................................................... 21,152 1,383 19,769

Hispanic origin1

Total ......................................................... 18,565 4,584 13,980

Poor ......................................................... 3,938 3,374 564

Nonpoor ...................................................... 14,627 1,210 13,417

Age

Under 18 ....................................................... 67,032 10,446 50,286

Total ......................................................... 10,183 8,248 1,936

Poor ......................................................... 50,549 2,198 48,350

Nonpoor .....................................................

18 to 64

Total ......................................................... 147,668 12,225 135,444

Poor ......................................................... 11,440 8,641 2,800

Nonpoor ...................................................... 136,229 3,585 132,644

65 and over

Total ......................................................... 27,411 2,326 25,084

Poor ......................................................... 2,226 1,909 316

Nonpoor ...................................................... 25,185 417 24,768

Sex

Male

Total ......................................................... 113,681 10,079 103,602

Poor ......................................................... 9,286 7,191 2,095

Nonpoor ...................................................... 104,395 2,888 101,507

Female

Total ......................................................... 122,131 14,919 107,212

Poor ......................................................... 14,564 11,606 2,957

Nonpoor ...................................................... 107,567 3,313 104,254

Educational Attainment (persons 18 years and over)

Less than 4 years of high school

Total ......................................................... 36,701 7,111 29,590

Poor ......................................................... 6,717 5,575 1,141

Nonpoor ...................................................... 29,984 1,535 28,449

High school graduate, no college

Total ......................................................... 66,051 5,008 61,043

Poor ......................................................... 4,596 3,489 1,107

Nonpoor ...................................................... 61,455 1,519 59,936

1 or more years of college

Total ......................................................... 72,328 2,433 69,895

Poor ......................................................... 2,354 1,485 868

Nonpoor ...................................................... 69,974 948 69,026

See footnotes at end of table.

21
Table 5. Transitions Into and Out of Poverty, by Selected Characteristics: 1990 to 1991—Continued

[Numbers in thousands]

Poverty status in 1990

Total

Poverty status in 1991

Poor Nonpoor

Region

Northeast

Total ......................................................... 47,722 3,881 43,841

Poor ......................................................... 3,768 2,936 832

Nonpoor ...................................................... 43,954 946 43,008

Midwest

Total ......................................................... 62,034 6,168 55,866

Poor ......................................................... 5,664 4,692 972

Nonpoor ...................................................... 56,371 1,476 54,894

South

Total ......................................................... 79,138 10,897 68,242

Poor ......................................................... 10,809 8,426 2,383

Nonpoor ...................................................... 68,329 2,470 65,859

West

Total ......................................................... 46,916 4,052 42,865

Poor ......................................................... 3,608 2,744 865

Nonpoor ...................................................... 43,308 1,308 42,000

Family Status

In married-couple families both years

Total ......................................................... 162,539 8,700 153,840

Poor ......................................................... 8,007 5,715 2,292

Nonpoor ...................................................... 154,532 2,985 151,547

In other family types both years

Total ......................................................... 33,108 10,043 23,065

Poor ......................................................... 9,886 8,679 1,207

Nonpoor ...................................................... 23,222 1,364 21,858

Unrelated individual both years

Total ......................................................... 28,132 4,480 23,652

Poor ......................................................... 4,390 3,593 797

Nonpoor ...................................................... 23,742 887 22,855

Work Experience (persons 18 years and over)

Worked year-round, full-time both years ............................ 68,330 824 67,506

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813 473 340

Poor ......................................................... 67,517 351 67,167

Nonpoor .....................................................

Worked, not year-round, full-time both years ........................ 32,448 3,521 28,928

Total ......................................................... 3,141 2,202 939

Poor ......................................................... 29,307 1,318 27,989

Nonpoor .....................................................

Did not work either year

Total ......................................................... 43,563 7,137 36,426

Poor ......................................................... 7,125 6,125 1,000

Nonpoor ...................................................... 36,438 1,013 35,425

Receipt of Public Assistance

Received public assistance both years2

Total ......................................................... 36,867 17,310 19,558

Poor ......................................................... 16,883 14,497 2,386

Nonpoor ...................................................... 19,985 2,813 17,172

Did not receive public assistance either year

Total ......................................................... 181,680 5,460 176,220

Poor ......................................................... 5,096 3,147 1,949

Nonpoor ...................................................... 176,584 2,313 174,272

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

22
Appendix A. Overview of the SIPP Program

BACKGROUND

The Survey of Income and Program Participation

(SIPP) provides a major expansion in the kind and

amount of information available to analyze the economic

situation of households and persons in the United

States. The information supplied by this survey is expected

to provide a better understanding of changes in the

well-being of the population and the relationship to the

demographic and social characteristics of individuals.

The data collected in SIPP will be especially useful in

studying Federal transfer programs, estimating program

cost and effectiveness, and assessing the effect of

proposed changes in program regulations and benefit

levels. Analysis of other important national issues such

as tax reform, Social Security program costs, and national

health insurance can be expanded and refined, based

on the information from this new survey.

The first interviews in the SIPP took place in October

1983, nearly 8 years after the research and developmental phase, the Income Survey Development Program (ISDP), was initiated by the Department of Health,

Education, and Welfare, in 1975. Between 1975 and

1980 extensive research was undertaken to design and

test new procedures for collecting income and related

socioeconomic data on a subannual basis and in a

longitudinal framework. Much of the work centered

around four experimental field tests that were conducted

in collaboration with the Bureau of the Census to

examine different concepts, procedures, questionnaires,

and recall periods. Two of the tests were restricted to a

small number of geographic sites; the other two were

nationwide. In the first nationwide test, the 1978 Research

Panel, approximately 2,000 households were interviewed.

Because of the relatively small number of interviews,

controlled experimental comparisons of alternatives were

not possible; however, the panel did demonstrate that

many new ideas and methods were feasible. It also laid

a foundation for the largest and most complex test: the

1979 Research Panel. This panel consisted of a nationally representative sample of 8,200 households and

provided a vehicle for feasibility tests and controlled

experiments of alternative design features.

In the fall of 1981, virtually all funding for ISDP

research and planning of the continuing SIPP program

was deleted from the budget of the Social Security

Administration. The loss of funding for fiscal year 1982

brought all work on the new survey to a halt. In fiscal

year 1983, however, money for initiation of the new

survey was allotted in the budget of the Bureau of the

Census. Work began almost immediately in preparation

for the survey start in October 1983. The design of the

questionnaire for the first interview was similar in structure to that used in the 1979 ISDP panel study with two

important exceptions. First, the reference period for the

questions was extended from 3 months to 4 months in

order to reduce the number of interviews and, therefore,

lower costs. Second, the questions covering labor force

activity were expanded in order to provide estimates that

were closer, on a conceptual basis, to those derived

from the Current Population Survey (CPS). The design

also incorporated a number of other modifications resulting from experience with the 1979 pilot study.

SURVEY CONTENT

There are three basic elements contained in the

overall design of the survey content. The first is a control

card used to record basic social and demographic

characteristics for each person in the household at the

time of the initial interview. Because households are

interviewed a total of eight or nine times, the card is also

used to record changes in characteristics and to record

the dates when persons enter or leave the household.

Finally, during each interview, information on each source

of income reviewed and the name of each job or

business is transcribed to the card so that this information can be used in the updating process in subsequent

interviews.

The second major element of the survey content is

the core portion of the questionnaire. The core questions

are repeated at each interview and cover labor force

activity, the types and amounts of income received

during the 4-month period, and participation status in

various programs. Some of the important elements of

labor force activity are recorded separately for each

week of the period. Income recipiency and amounts are

recorded on a monthly basis with the exception of

amounts of property income (interest, dividends, rent,

etc.). Data for these types are recorded as totals for the

4-month period. The core also contains questions covering attendance in postsecondary schools, private health

insurance coverage, public or subsidized rental housing,

low-income energy assistance, and school breakfast

and lunch participation.

A-1
The third major element is the various supplements or

topical modules that will be included during selected

household visits. The topical modules cover areas that

need not be examined every 4 months. Certain of these

topical modules are considered to be so important that

they are viewed as an integral part of the overall survey.

Other topical modules have more specific and more

limited purposes. Topical modules which were covered

in the various waves of the 1990 SIPP panel are shown

in table A-1. (For a definition of the term ‘‘wave,’’ see

table A-2 and the following section.)

SAMPLE DESIGN

The sample design for the first SIPP panel in 1984

consisted of about 20,000 households selected to represent the noninstitutionalized population of the United

States. The subsequent 1990 panel used in this report

had a sample size of approximately 21,900 households.

Table A-2 shows the sample design for the 1990 panel

of SIPP. Each household in the sample was scheduled

to be interviewed at 4-month intervals over a period of

2-1/2 years beginning in February 1990. The reference

period for the questions is the 4-month period preceding

the interview. For example, households interviewed in

February 1990 were asked questions for the months

October, November, and December 1989 and January

1990. This household was interviewed again in June

1990 for the February through May period. The sample

households within a given panel are divided into four

subsamples of nearly equal size. These subsamples are

called rotation groups and one rotation group is interviewed each month. In general, one cycle of four

interviews covering the entire sample, using the same

questionnaire, is called a wave. This design was chosen

because it provides a smooth and steady work load for

data collection and processing.

SIPP panels have been introduced in February of

each succeeding year. This overlapping design provides

a larger sample size from which cross-sectional estimates can be made. The overlap also enhances the

survey’s ability to measure change by lowering the

standard errors on differences between estimates for

two points in time.

Table A-1. Topical Modules for the 1990 SIPP

Panel

Wave Modules

1 None

2 Recipiency history

Employment history

Work disability history

Education and training history

Marital history

Migration history

Fertility history

Household relationships

3 Work schedule

Childcare arrangements and child support agreements

Support for nonhousehold members

Functional limitations and disability

Utilization of health care services

4 Assets and liabilities

Retirement expectations and pension plan coverage

Real estate property and vehicles

5 Annual income and retirement Accounts

Taxes

School enrollment and financing

6 Childcare arrangements and child support agreements

Support for nonhousehold members

Functional limitations and disability

Utilization of health care services

Spells outside of the work force

7 Selected financial assets

Medical expenses and work disability

Real estate, shelter costs, dependent care, and

vehicles

8 Annual income and retirement accounts

Taxes

School enrollment and financing

Table A-2. Design of the 1990 SIPP Panel

Rotation Wave

Interview

month Reference months

2 1 Feb. 90 Oct., Nov., Dec. (89), Jan.(90)

3 1 March 90 Nov., Dec. (89), Jan.,Feb.(90)

4 1 April 90 Dec.,(89), Jan., Feb., Mar.(90)

1 1 May 90 Jan., Feb., Mar., Apr.(90)

2 2 June 90 Feb., Mar., Apr., May (90)

3 2 July 90 Mar., Apr. May, Jun.(90)

4 2 Aug. 90 Apr., May Jun., Jul.(90)

1 2 Sept. 90 May, Jun., Jul., Aug. (90)

2 3 Oct. 90 Jun., Jul., Aug., Sept. (90)

3 3 Nov. 90 Jul., Aug., Sept., Oct. (90)

4 3 Dec. 90 Aug., Sept., Oct., Nov. (90)

1 3 Jan. 91 Sept., Oct., Nov., Dec. (90)

2 4 Feb. 91 Oct., Nov., Dec. (90), Jan (91)

3 4 March 91 Nov., Dec. (90), Jan., Feb. (91)

4 4 April 91 Dec. (90), Jan., Feb., Mar. (91)

1 4 May 91 Jan., Feb., Mar., Apr. (91)

2 5 June 91 Feb., Mar., Apr., May (91)

3 5 July 91 Mar., Apr., May, Jun. (91)

4 5 Aug. 91 Apr., May, Jun., Jul. (91)

1 5 Sept. 91 May, Jun., Jul., Aug. (91)

2 6 Oct. 91 Jun., Jul., Aug., Sept. (91)

3 6 Nov. 91 Jul., Aug., Sept., Oct. (91)

4 6 Dec. 91 Aug., Sept., Oct., Nov. (91)

1 6 Jan. 92 Sept., Oct., Nov., Dec. (91)

2 7 Feb. 92 Oct., Nov., Dec. (88), Jan. (92)

3 7 March 92 Nov., Dec. (91), Jan., Feb. (92)

4 7 April 92 Dec. (91), Jan., Feb., Mar. (92)

1 7 May 92 Jan., Feb., March, April (92)

2 8 June 92 Feb., Mar., Apr., May (92)

3 8 July 92 Mar., Apr., May, Jun. (92)

4 8 Aug. 92 Apr., May, Jun., Jul. (92)

1 8 Sept. 92 May, Jun., Jul., Aug. (92)

A-2
SURVEY OPERATIONS

Data collection operations are managed through the

Census Bureau’s 12 permanent regional offices. A staff

of interviewers assigned to SIPP conduct interviews by

personal visit each month with most interviewing completed during the first 2 weeks of that month. Completed

questionnaires are transmitted to the regional offices

where they undergo an extensive clerical edit before

being entered into the Bureau’s SIPP data processing

system. Upon entering this processing system the data

are subjected to a detailed computer edit. Errors identified in this phase are corrected and computer processing continues.

Two of the major steps of computer processing are

the assignment of weights to each sample person and

imputation for missing survey responses. The weighting

procedures assure that SIPP estimates of the number of

persons agree with independent estimates of the population within specified age, race, and sex categories.

The procedures also assure close correspondence with

monthly CPS estimates of households. In almost all

cases, a survey nonresponse is assigned a value in the

imputation phase of processing. The imputation for

missing responses is based on procedures generally

referred to as the ‘‘hot deck’’ approach. This approach

assigns values for nonresponses from sample persons

who did provide responses and who have characteristics similar to those of the nonrespondents.

The longitudinal design of SIPP dictates that all

persons 15 years old and over present as household

members at the time of the first interview be part of the

survey throughout the entire 2 1/2 year period. To meet

this goal, the survey collects information useful in locating persons who move. In addition, field procedures

were established that allow for the transfer of sample

cases between regional offices. Persons moving within a

100-mile radius of an original sampling area (a county or

group of counties) are followed and continue with the

normal personal interviews at 4-month intervals. Those

moving to a new residence that falls outside the 100-

mile radius of any SIPP sampling area are interviewed

by telephone. The geographic areas defined by these

rules contain more than 95 percent of the U.S. population.

Because most types of analysis using SIPP data will

be dependent not on data for individuals but on groups

of individuals (households, families, etc.), provisions

were made to interview all ‘‘new’’ persons living with

original sample persons (those interviewed in the first

wave). These new sample persons entering the survey

through contact with original sample persons are considered as part of the sample only while residing with the

original sample person.

A-3
Appendix B. Definitions and Explanations

Population coverage. The estimates in this report are

restricted to the civilian noninstitutional resident population of the United States and members of the Armed

Forces living off post or with their families on post.

Weights. Five sets of weights were used in this report.

Monthly weights for calendar years 1990 and 1991 were

used in deriving average monthly poverty figures for

each year. Estimates of the number of persons who ever

were poor during the panel, who were poor all of 1990

and 1991, and who experienced a change in poverty

status from 1990 to 1991 were based on the 1990 panel

weight. Calendar year weights for 1990 and 1991 were

used to obtain estimates of the number of persons who

were ever participated during a given year.

Race and Hispanic origin. The population is divided

into two groups on the basis of race: White and Black.

Persons of Hispanic origin were determined on the basis

of a question that asked for self-identification of the

person’s origin (or the origin of some other household

member) from a ‘‘flashcard’’ listing ethnic origins. Hispanics were those who indicated that their origin was

Mexican, Puerto Rican, Cuban, Central or South American, or some other Hispanic origin. Persons of Hispanic

origin may be of any race.

Householder. The instructions call for listing first the

person (or one of the persons) in whose name the home

is owned or rented. If the house is owned jointly by a

married couple, either the husband or the wife may be

listed first, thereby becoming the reference person, or

householder, to whom the relationship of the other

household members is recorded. One person in each

household is designated as the ‘‘householder.’’ The

number of householders, therefore, is equal to the

number of households.

Family. The term ‘‘family’’ refers to a group of two or

more persons related by birth, marriage, or adoption

who reside together; all such persons are considered as

members of one family. For example, if the son of the

person who maintains the household and the son’s wife

are members of the household, they are treated as

members of the parent’s family. Every family must

include a householder; two or more people living in the

same household who are related to one another, but are

not related to the householder, form an ‘‘unrelated

subfamily.’’

Subfamily. A subfamily is a married couple with or

without children, or one parent with one or more own

single children under 18 years old living in a household

but not including among its members the person or

couple maintaining the household. Because a subfamily

does not include a householder, it is by definition

excluded from the count of families. There are two kinds

of subfamilies, related and unrelated.

Related subfamily. A related subfamily is a subfamily

whose members are related to the person or couple

maintaining the household. The most common example

of a related subfamily is a young married couple sharing

the home of the husband’s or wife’s parents. Members

of a related subfamily are also members of the householder’s family.

Unrelated subfamily. An unrelated subfamily is a

subfamily whose members are not related to the person

or couple maintaining the household. Persons in unrelated subfamilies are not part of the householder’s

family, but are classified by family status as if they were

separate families. They are included in the overall count

of family members.

Married-couple family. A married couple, as defined

for census purposes, is a husband and wife enumerated

as members of the same household. The married couple

may or may not have children living with them. The

expression ‘‘husband-wife’’ or ‘‘married-couple’’ before

the term ‘‘household,’’ or ‘‘family’’ indicates that the

household, or family, is maintained by a husband and

wife.

Unrelated individuals. The term ‘‘unrelated individuals’’ refers to persons 15 years old and over (other than

inmates of institutions) who are not living with any

relatives. An unrelated individual may (1) constitute a

one-person household, (2) be part of a household

including one or more other families or unrelated individuals, or (3) reside in group quarters such as a

rooming house. Thus, a widow living by herself or with

one or more other persons not related to her, a lodger

not related to the householder or to anyone else in the

household, and a servant living in an employer’s household with no relatives are examples of unrelated individuals. The poverty status of unrelated individuals is

determined independently of other household members’

incomes.

B-1
Educational attainment. The definitions of educational

attainment relate to persons 18 years old and older.

Data on years of school completed were derived from

the combination of answers to questions concerning the

highest grade of school attended by the person and

whether or not that grade was finished. The questions of

educational attainment apply only to progress in ‘‘regular’’ schools. Such schools included public, private, and

parochial elementary and high schools (both junior and

senior), colleges, universities, and professional schools

(whether day schools or night schools). Thus, regular

schooling is that which may advance a person toward an

elementary school certificate, a high school diploma, or

a college, university, or professional school degree.

Metropolitan areas. The population residing in metropolitan statistical areas (MSAs) as defined in June 1984

constitutes the metropolitan population. MSAs are defined

by the Office of Management and Budget for use in the

presentation of statistics by agencies of the Federal

Government. An MSA is a geographic area consisting of

a large population nucleus, together with adjacent communities which have a high degree of economic and

social integration with that nucleus. The definitions

specify a boundary around each large city so as to

include most or all its suburbs. Entire counties form the

MSA building blocks, except in New England where

cities and towns are used. The former term SMSA was

changed to MSA in 1983.

An area qualifies for recognition as an MSA if (1) it

includes a city of at least 50,000 population, or (2) it

includes a Census Bureau-defined urbanized area of at

least 50,000 with a total metropolitan population of at

least 100,000 (75,000 in New England). In addition to

the county containing the main city or urbanized area, an

MSA may include other counties having strong commuting ties to the central county. If specified conditions are

met, certain large MSAs are designated as consolidated

MSAs (CMSAs) and divided into component primary

MSAs (PMSAs).

Non-metropolitan areas. The territory outside metropolitan statistical areas is referred to here as nonmetropolitan.

Central cities. The largest city in each MSA is always

designated a central city. There may be additional

central cities if specified requirements, designed to

identify places of central character within the MSA, are

met. Although the largest central cities are generally

included in the title of the MSA, there may be central

cities that are not part of the title. The balance of the

MSA outside the central city or cities often is regarded

as equivalent to ‘‘suburban areas.’’

Non-central cities. The territory outside central cities

of metropolitan statistical areas but within MSAs is

referred to here as outside central cities or ‘‘suburban

areas.’’

Labor force and employment status. The definitions

of labor force and employment status relate to persons

18 years old and older.

Full-time employed. A person was employed full-time

in a given month if he or she worked at least one week

during that month and at least 35 hours during a usual

week of employment.

Part-time employed. A person was employed parttime in a given month if he or she worked at least one

week during that month and less than 35 hours during a

usual week of employment.

Unemployed. A person was unemployed in a given

month if he or she had no job during the month and

spent one or more weeks looking for employment or on

layoff.

Not in the labor force. A person was not in the labor

force in a given month if he or she held no job during the

month and spent no time looking or on layoff.

Disability. Respondents were asked every wave whether

they have a physical, mental, or other health condition

which limits the kind or amount of work they can

perform. On the longitudinal file (which was used for this

analysis) a person is recorded as disabled if he/she

answered yes to this question at least once during the

panel.

Reference periods for the characteristics age, education, employment status, family status, marital

status, family size, residence, region, receipt of

assistance, and health insurance coverage. While

residence, region, and employment status are observed

each wave, the other characteristics are observed each

month. In order to calculate average monthly statistics,

the characteristics are used as they prevail in the

particular month. In order to determine the number of

persons who ever or always were poor during a given

time period, the characteristics are used as of the first

month (wave) of the time period in question. When

looking at spells of poverty, the characteristics of persons experiencing the spells are as of the month (wave)

during which the spell began.

Income. The cash income concept used in this report

includes the sum of all income received from any of the

sources listed in table B-1. Rebates, refunds, loans and

capital gain or loss amounts from the sale of assets, and

interhousehold transfers of cash such as allowances are

not included.

B-2
Accrued interest on Individual Retirement Accounts,

KEOGH retirement plans, and U.S. Savings bonds are

also excluded. This definition differs somewhat from that

used in the annual income reports based on the March

CPS income supplement questionnaire. The data in

those reports, published in the Current Population Reports,

Series P-60, are based only on income received in a

regular or periodic manner and, therefore, exclude lumpsum or one-time payments, such as inheritances, or

insurance settlements which are included as income in

SIPP. Educational assistance, which is included in the

March CPS income concept, is not included in the SIPP

income concept.

The income amounts represent amounts actually

received during the month, before deductions for income

and payroll taxes, union dues, Part B Medicare premiums, etc.

The SIPP income definition includes three types of

earnings: wages and salary, nonfarm self-employment,

and farm selfemployment. The definition of nonfarm

self-employment and farm self-employment is not based

on the net difference between gross receipts or sales on

the one hand and operating expenses, depreciation, etc.

on the other. Rather, the monthly amounts for these

income types are based on the salary or other income

received from the business by the owner of the business

or farm during the 4-month period.

While the income amounts from most sources are

recorded monthly for the 4-month reference period,

property income amounts such as interest, dividends,

and rental income were recorded as totals for the

4-month period. These totals were distributed equally

between months of the reference period for purposes of

calculating poverty status in this report.

Poverty definition. The poverty definitions used in this

report are based on the government’s official definition

but were calculated on a monthly basis using the family

composition at that time rather than fixing it throughout

the year as is done in the Current Population Survey.

These data differ from the official figures and are not part

of the standard data series on poverty established by

Directive 14 from the Office of Management and Budget.

Official figures are published annually from the March

Current Population Survey in the P-60 Series of Current

Population Reports.

The poverty definition is based on an index developed at the Social Security Administration in 1964 and

revised by Federal interagency committees in 1969 and

1981. The poverty concept is a statistical measure

based on the Department of Agriculture’s 1961 Economy

Food Plan. It reflects the different consumption requirements of families in relation to their size and composition, and the age of the family householder. A ratio of

food expenditures to income of one-third, based on the

Department of Agriculture’s 1955 Survey of Food Consumption, was used to derive the original poverty thresholds from the economy food plan. The poverty thresholds have been updated annually based on changes in

the Consumer Price Index.

Weighted average poverty thresholds for 1990 and

1991 are shown below in table B-2.

Table B-1. Income Sources Included in Monthly

Cash Income

Earnings from employment

Wages and salary

Nonfarm self-employment income

Farm self-employment income

Income from assets (property income)

Regular/passbook savings accounts in a bank, savings and loan

or credit union

Money market deposit accounts

Certificate of deposit

NOW, Super NOW, or other interest-earning checking accounts

Money market funds

U.S. Government securities

Municipal or corporate bonds

Other interest-earning assets

Stocks or mutual fund shares

Rental property

Mortgages

Royalties

Other financial investments

Other income sources

Social Security

U.S. Government Railroad Retirement

Federal Supplemental Security Income

State administered Supplemental Security Income

State unemployment compensation

Supplemental unemployment benefits

Black lung payments

Worker’s compensation

State temporary sickness or disability benefits

Employer or union temporary sickness policy

Payments from a sickness, accident, or disability insurance

policy purchased on your own

Aid to Families with Dependent Children (AFDC), (ADC)

General Assistance or General Relief

Indian, Cuban, or refugee assistance

Foster child care payments

Other welfare

Child support payments

Alimony payments

Pensions from a company or union

Federal civil service or other Federal civilian employee

pensions

U.S. military retirement

National Guard or Reserve Forces retirement

State government pensions

Local government pensions

Income from paid-up life insurance policies or annuities

Estates and trusts

Other payments for retirement, disability or survivors, G.I.

Bill/VEAP education benefits

Income assistance from a charitable group

Other unemployment compensation (Trade Adjustment Act

benefits, strike pay, other)

Veterans’ compensation or pensions

Money from relatives or friends

Lump sum payments

Income from roomers or boarders

National Guard or Reserve pay

Incidental or casual earnings

Other cash income not included elsewhere

B-3
For further discussion of the poverty definition, see

Current Population Reports, Series P-60, No. 188, Income,

Poverty, and Valuation of Noncash Benefits: 1993.

Income-to-poverty ratio. The income-to-poverty ratios

used in this report incorporates an adjustment in every

month for family size and composition. The poverty

threshold for each family is calculated based on the size

and composition of that family in each month. For

unrelated individuals, individual income is divided by the

appropriate one-person-family poverty threshold. Monthly

estimates of poverty are obtained by comparing monthly

family income to monthly thresholds. In order to obtain

the income-to-poverty ratio during a certain period, the

family income of a person is summed over each month

of that period and divided by the sum of the respective

monthly poverty thresholds.

Thus, a person’s annual poverty status in this report

was determined by comparing the sum of the person’s

family income each month against the sum of the

appropriate monthly poverty thresholds. If the person’s

family income (personal income if an unrelated individual) was below the sum of the monthly poverty

thresholds, the person was classified as below the

poverty level for the year shown.

Public Assistance. Persons are considered recipients

of public assistance if they receive assistance from one

or more of the following programs: Aid to Families with

Dependent Children (AFDC), General Assistance, Supplemental Security Income, food stamps, Medicaid, and

housing assistance.

AFDC. Title VII of the Social Security Act permits States

to give cash assistance to needy children who lack

financial support of one parent because a parent is

continuously absent from home, incapacitated, dead, or

unemployed.1 The Federal and State government share

in the cost of benefit payments and administrative

outlays and some States require local governments to

share costs. Able-bodied AFDC recipients are required

by federal law to register for training and employment

services. Mothers receiving AFDC payments are required

to assign their child support rights to the State and to

cooperate in establishing paternity of a child born out of

wedlock.

Persons are considered participants in AFDC if they

are identified as primary recipients or if they are covered

under other persons’ allotment.

General Assistance. General Assistance consists of a

host of state and local programs to provide cash assistance to needy persons not qualifying for AFDC or SSI.

Eligibility rules vary from State to State, and often from

county to county within a State, ranging from aid to

mostly unemployable single adults (District of Columbia), to workfare programs, where recipients work in

exchange for the assistance (New York).

Persons are considered participants in General Assistance if they are identified as primary recipients or if they

are covered under other persons’ allotment.

Federal and State rent assistance. There are several

programs designed to ‘‘remedy the unsafe and unsanitary housing conditions and the acute shortage of decent,

safe, and sanitary dwellings for families of low income.’’2

Among these, the most important are Low Rent Public

Housing and Sections 8, 236, and 101 of the U.S.

Housing Act, all of which are funded in full by the Federal

Government. Under sections 8 and 101, Federal funds

are used to subsidize private sector housing. The difference between the ‘‘fair market’’ rent and the rent charged

to the tenant is paid to the owner by the government.

Under an interest reduction program (e.g. section 236),

the amount of interest paid on the mortgage by the

owner is reduced and the subsequent savings are

passed on to low-income tenants in the form of lower

rent charges.

Participation in public housing is determined by two

factors: program eligibility and the availability of housing.

Income standards for initial and continuing occupancy

vary by local housing authority, although the limits are

constrained by Federal guidelines. Rental charges, which,

in turn, define net benefits, are set by a Federal statute

not to exceed 25 percent of net monthly money income.

1

The Family Support Act of 1988 requires all jurisdictions with

AFDC programs to extend benefits to children in two-parent families in

which the principal earner is unemployed (AFDC-UP). Jurisdictions

with such a program already in place must continue year round

support for such families. Other jurisdictions have to cover such

families for 6 out of 12 months. The law took effect October 1, 1990 for

the States and the District and two years later for the outlying areas. 2

From P.L. 75-412, ‘‘The United States Housing Act of 1937,’’

declaration of policy.

Table B-2. Weighted Average Poverty Thresholds

in 1990 and 1991

Characteristic

Thresholds

1990 1991

One person (unrelated individual) ...... $6,652 $6,932

15 to 64 years ..................... 6,800 7,086

65 years and over.................. 6,268 6,532

Two persons......................... 8,509 8,865

Householder 15 to 64 years ......... 8,794 9,165

Householder 65 years and over...... 7,905 8,241

Three persons ....................... 10,419 10,860

Four persons ........................ 13,359 13,924

Five persons......................... 15,792 16,456

Six persons.......................... 17,839 18,587

Seven persons....................... 20,241 21,093

Eight persons ........................ 22,582 23,532

Nine persons or more................. 26,848 27,978

B-4
A recipient unit can either be a family of two or more

related persons or an individual who is handicapped,

elderly, or displaced by urban renewal or natural disaster.

Federal law mandates that, as a total among all

assisted housing programs, at most 25 percent of units

being re-rented and 5 percent of units that become

available can be rented to households with incomes

between 50 and 80 percent of the area median.3 All

other units are to be reserved for families at or below 50

percent of the area median.

SIPP survey respondents were asked whether their

residence is owned by a local housing authority or

whether the Federal, State or local government is paying

part of the rent. A ‘‘yes’’ to either question identified the

respondent and others living at the same residence as

participants in a Public or subsidized rental housing

program.

Food stamps. The Food Stamp Act of 1977 defines

this Federally funded program as one intended to ‘‘permit low-income households to obtain a more nutritious

diet.’’4 Food purchasing power is increased by providing

eligible households with coupons which can be used to

purchase food. The Food and Nutrition Service of the

U.S. Department of Agriculture (USDA) administers the

Food Stamp Program through State and local welfare

offices. The Food Stamp Program is the major national

income support program which provides benefits to all

low-income and low-resource households regardless of

household characteristics (e.g., sex,age, and disability).

The questions on participation in the Food Stamp Program in SIPP were designed to identify households in

which one or more of the current members received food

stamps. Once a food stamp household was identified, a

question was asked to determine the number of current

household members covered by food stamps. Questions also were asked about the number of months food

stamps were received and the total face value of all food

stamps received during the period.

Medicaid. The Medicaid Program is designed ‘‘to furnish medical assistance on behalf of needy families with

dependent children, and of aged, blind, or permanently

and totally disabled individuals whose incomes and

resources are insufficient to meet the costs of necessary

medical services.’’5 The program is administered by

State agencies through grants from the Health Care

Financing Administration of the Department of Health

and Human Services. Funding for medical assistance

payments consists of a combination of Federal, State,

and in some cases, local resources.

Medicaid is for the most part a categorical program

with complex eligibility rules which vary from State to

State. There are two basic groups of eligible individuals:

the categorically eligible and the medically needy. The

major categorically eligible groups are all Aid to Families

with Dependent Children (AFDC) recipients and most

Supplemental Security Income (SSI) recipients. Other

categorically eligible groups are those who meet basic

State cash assistance eligibility rules (the aged, blind, or

disabled; needy single parents with children; and, in

some States, needy unemployed parents with children

who are not currently receiving money payments), and

needy persons who meet categorical eligibility standards but are institutionalized for medical reasons (e.g.,

low-income elderly persons in nursing homes). However, such institutionalized persons are not included in

the SIPP universe and, therefore, are not reflected in

these statistics.

In roughly one-half of the States, coverage is extended

to the medically needy: persons meeting categorical

age, sex, or disability criteria whose money incomes and

assets exceed eligibility levels for cash assistance but

are not sufficient to meet the cost of medical care. In

such States, qualifying income and asset levels are

usually above those set for cash assistance. Families

with large medical expenses relative to their incomes

and assets may also meet medically needy eligibility

standards in these States.

The Medicaid question in SIPP attempted to identify

all adults who were covered by Medicaid. The term

‘‘covered’’ means enrolled in the Medicaid program, e.g.

had a Medicaid medical assistance card or incurred

medical bills which were paid for by Medicaid. In order to

be counted, the person did not have to receive medical

care paid for by Medicaid. Coverage was assigned in

situations where it was not reported but should have

been, i.e. where persons were categorically eligible

through their reported participation in other cash transfer

programs.

Supplemental Security Income. Authorized as Title

XVI of the Social Security Act by the Social Security

Amendments of 1972 and implemented in 1974, the SSI

program provides cash benefits, paid monthly, to aged,

blind, and disabled persons who are financially needy

according to criteria governing both income and assets.

The program is allied with optional State Supplementation Programs (SSPs), which raise the levels of payments to amounts desired by individual states. SSI/SSP,

which covers people of all ages, replaced federal grants

3

See P.L. 100-242 of the ‘‘Housing and Community Development

Act of 1987’’. 4

From Ttitle XIII of P.L. 95-113, ‘‘The Food Stamp Act of 1977,’’

declaration of policy. 5

From Title XIX of the 1965 Amendments to P.L. 89-97, The Social

Security Act, ‘‘Grants to States for Medical Assistance Programs,’’

declaration of policy.

B-5
to the states for old-age assistance and aid to blind and

permanently and totally disabled adults. A person is

considered a participant in the SSI program during a

given month, if he/she received payments from the U.S.

Government or from a State or local welfare office during

that month.

Symbols. A dash (—) represents zero or rounds to

zero, ‘‘B’’ means that the base for the derived figure is

less than 200,000, and ‘‘X’’ means not applicable.

Rounding. Percentages are rounded to the nearest

tenth of a percent; therefore, the percentages in a

distribution do not always add to exactly 100.0 percent.

The totals, however, are always shown as 100.0. Moreover, individual figures are rounded to the nearest

thousand without being adjusted to group totals, which

are independently rounded; percentages are based on

the unrounded numbers.

B-6
Appendix C. Source and Accuracy of the Estimates

SOURCE OF DATA

The SIPP universe is the noninstitutionalized resident

population living in the United States. This population

includes persons living in group quarters, such as

dormitories, rooming houses, and religious group dwellings. Not eligible to be in the survey are crew members

of merchant vessels, Armed Forces personnel living in

military barracks, and institutionalized persons, such as

correctional facility inmates and nursing home residents.

Also not eligible are United States citizens residing

abroad. Foreign visitors who work or attend school in

this country and their families are eligible; all others are

not eligible. With the exceptions noted above, field

representatives interview eligible persons who are at

least 15 years of age at the time of the interview.

The SIPP sample for the 1987 and 1990 panels is

located in 230 Primary Sampling Units (PSUs) each

consisting of a county or a group of contiguous counties.

Within these PSUs, we systematically selected expected

clusters of two living quarters from lists of addresses

prepared for the 1980 decennial census to form the bulk

of the sample. To account for living quarters built within

each of the sample areas after the 1980 census, we

selected a sample containing clusters of four living

quarters from permits issued for construction of residential living quarters up until shortly before the beginning of

the panel.

In jurisdictions that have incomplete addresses or do

not issue building permits, we sampled small land areas,

listed expected clusters of four living quarters, and then

subsampled. In addition, we selected a sample of living

quarters from a supplemental frame that included living

quarters identified as missed in the 1980 census.

The 1990 panel differs from other panels as a result of

oversampling for low income households. The panel

contains an oversample of Black-headed households,

Hispanic-headed households, and female-headed family households with no spouse present and living with

relatives.

For the 1987 and 1990 panels, the first interviews

occurred during February, March, April, or May of 1987

and 1990, respectively. Interviews for approximately

one-fourth of the sample took place in each of these

months creating four subsamples. The four subsamples

distribute interviewing workloads and are called rotation

groups. One round of interviewing for the sample covering all four rotations is called a wave. For the remainder of the panel, interviews for each person occurred

every 4 months. At each interview, the reference period

was the 4 months preceding the interview month.

Occupants of about 93 percent of all eligible living

quarters participated in the first interview of the panel.

For later interviews, field representatives interviewed

only original sample persons (those in Wave 1 sample

households and interviewed in Wave 1) and persons

living with them. The Census Bureau automatically

designated all first-wave noninterviewed households as

noninterviews for all subsequent interviews.

For the 1987 panel, field representatives conducted

personal interviews for all waves. For the 1990 panel,

field representatives conducted personal interviews in

the first through sixth waves only. The remaining interviews for the 1990 panel were designated telephone

interviews. Even though headquarters designated an

interview as personal or telephone, the field representatives may have conducted either type of interview

depending on the circumstances of a case.

For personal interviews, we followed original sample

persons if they moved to a new address, unless the new

address was more than 100 miles from a SIPP sample

area. If the original sample persons moved farther than

100 miles from a SIPP sample area, we attempted

telephone interviews. When original sample persons

moved to remote parts of the country and were unreachable by telephone, moved without leaving a forwarding

address, or refused the interview, additional noninterviews resulted.

We classified a person as interviewed or noninterviewed for the entire panel and both calendar years

based on the following definitions. Interviewed sample

persons are—

(1) those for whom self or proxy responses were

obtained for each reference month of all seven

interviews for the 1987 panel or eight interviews

for the 1990 panel, and all three interviews for

each calendar year; or

(2) those for whom self or proxy responses were

obtained for the first reference month of the

interview period and for each later reference

month until they were known to have died or

moved to an ineligible address (foreign living

quarters, institutions, or military barracks).

C-1
Details on interview-status classification are in ‘‘Weighting of Persons for SIPP Longitudinal Tabulations’’ (paper

by Judkins, Hubble, Dorsch, McMillen, and Ernst in the

1984 Proceedings of the Survey Research Methods

Section, American Statistical Association). Details on

patterns of nonresponse are in ‘‘Weighting Adjustment

for Partial Nonresponse in the 1984 SIPP Panel’’ (paper

by Lepkowski, Kalton, and Kasprzyk in the 1989 Proceedings of the Survey Research Methods Section,

American Statistical Association).

Some estimates are based on monthly averages from

cross-sectional files. Nonresponse rates for the months

on the files vary from 7 percent to 20.5 percent for the

1987 panel and from 7 percent to 21 percent for the

1990 panel. (See ‘‘SIPP 86 and 87: Source and Accuracy Statement for 1986 and 1987 Panel Public Use files

- Revision,’’ dated January 17, 1990, and ‘‘SIPP 90:

Source and Accuracy Statement for 1990 Panel Public

Use Files - Revision 2,’’ dated May 13, 1992.)

Some respondents did not respond to some of the

questions. Therefore, the overall nonresponse rate for

some items, especially sensitive income and money

related items, is higher than the person nonresponse

rate. For more discussion of nonresponse, see the

Quality Profile for the Survey of Income and Program

Participation, May 1990, by T. Jabine, K. King, and R.

Petroni, available from Customer Services, Data Users

Services Division (301-763-4100).

ESTIMATION

We used several stages of weight adjustments in the

estimation procedure to derive the SIPP longitudinal

person weights. We gave each person a base weight

equal to the inverse of his/her probability of selection.

We applied two noninterview adjustment factors. One

adjusted the weights of interviewed persons in interviewed households to account for households that were

eligible for the sample but which field representatives

could not interview at the first interview. The second

compensated for person noninterviews occurring in subsequent interviews. The Bureau used complex techniques to adjust the weights for nonresponse, but the

success of these techniques in avoiding bias is unknown.

For more detail on noninterview adjustment for longitudinal estimates, see Nonresponse Adjustment Methods

for Demographic Surveys at the U.S. Bureau of the

Census, November 1988, Working paper 8823, by R.

Singh and R. Petroni.

We applied another factor to each interviewed person’s

weight to account for the SIPP sample areas not having

the same population distribution as the strata they are

from.

We performed an additional stage of adjustment to

longitudinal person weights to reduce the mean square

error of the survey estimates. We accomplished this by

ratio adjusting the sample estimates to agree with

monthly Current Population Survey (CPS) type estimates of the civilian (and some military) noninstitutional

population of the United States at the national level by

demographic characteristics including age, sex, and

race, as of the specified control date. For the 1987

panel, the control date is March 1, 1987. For the 1990

panel, the control date is March 1, 1990. The 1987

calendar year and 1988 calendar-year control dates are

January 1, 1987, and January 1, 1988, respectively. The

1990 calendar year and 1991 calendar-year control

dates are January 1, 1990, and January 1, 1991,

respectively. The Bureau brought CPS estimates by

age, sex, and race into agreement with adjusted estimates from the 1980 decennial census. Adjustments to

the 1980 decennial census estimates reflect births,

deaths, immigration, emigration, and changes in the

Armed Forces since 1980. Also, we controlled SIPP

estimates to independent Hispanic controls.

ACCURACY OF ESTIMATES

We base SIPP estimates on a sample. The sample

estimates may differ somewhat from the values obtained

from administering a complete census using the same

questionnaire, instructions, and enumerators. The difference occurs because a sample survey estimate is

subject to two types of errors: nonsampling and sampling. We can provide estimates of the magnitude of the

SIPP sampling error, but this is not true of nonsampling

error. The next few sections describe SIPP nonsampling

error sources, followed by a discussion of sampling

error, its estimation, and its use in data analysis.

Nonsampling Variability. We attribute nonsampling

errors to many sources; they include the following:

x Inability to obtain information about all cases in the

sample.

Table C-1. Statistics of Person 0+ for Longitudinal

Panels and Calendar Years: 1987

and 1990

Panel

Initially

eligible

Classified

as

interviewed

Person

nonresponse

rate

(percent)

87P . . . . . . . . . . . . . . . . . . . . . . . . . . 33,100 24,400 26

87CY . . . . . . . . . . . . . . . . . . . . . . . . . 33,100 26,400 20

88CY . . . . . . . . . . . . . . . . . . . . . . . . . 34,800 25,800 26

90P . . . . . . . . . . . . . . . . . . . . . . . . . . 61,700 43,700 29

90CY . . . . . . . . . . . . . . . . . . . . . . . . . 61,700 49,600 20

91CY . . . . . . . . . . . . . . . . . . . . . . . . . 67,400 47,500 30

C-2
x Definitional difficulties.

x Differences in the interpretation of questions.

x Inability or unwillingness on the part of the respondents to provide correct information.

x Inability to recall information.

x Errors made in collection (e.g. recording or coding the

data).

x Errors made in processing the data.

x Errors made in estimating values for missing data.

x Biases resulting from the differing recall periods caused

by the interviewing pattern used.

x Undercoverage.

We used quality control and edit procedures to reduce

errors made by respondents, coders, and interviewers.

More detailed discussions of the existence and control

of nonsampling errors in the SIPP are in the SIPP

Quality Profile.

Undercoverage in SIPP resulted from missed living

quarters and missed persons within sample households.

It is known that undercoverage varies with age, race,

and sex. Generally, undercoverage is larger for males

than for females and larger for Blacks than for nonBlacks. Ratio estimation to independent age-race-sex

population controls partially corrects for the bias resulting from survey undercoverage. However, biases exist

in the estimates when persons in missed households or

missed persons in interviewed households have characteristics different from those of interviewed persons in

the same age-race-sex group. Further, we did not adjust

the independent population controls for undercoverage

in the census.

A common measure of survey coverage is the coverage ratio, the estimated population before ratio adjustment divided by the independent population control.

Table C-2 shows CPS coverage ratios for age-sex-race

groups for 1992. The CPS coverage ratios can exhibit

some variability from month to month, but these are a

typical set of coverage ratios. Other Census Bureau

household surveys like the SIPP experience similar

coverage.

Comparability with Other Estimates. Exercise caution when comparing data from this report with data from

other SIPP publications or with data from other surveys. Comparability problems are from varying seasonal

patterns for many characteristics, different nonsampling

errors, and different concepts and procedures. Refer to

the SIPP Quality Profile for known differences with data

from other sources and further discussion.

Sampling Variability. Standard errors indicate the

magnitude of the sampling error. They also partially

measure the effect of some nonsampling errors in

response and enumeration, but do not measure any

systematic biases in the data. The standard errors

mostly measure the variations that occurred by chance

because we surveyed a sample rather than the entire

population.

USES AND COMPUTATION OF STANDARD

ERRORS

Confidence Intervals. The sample estimate and its

standard error enable one to construct confidence intervals, ranges that would include the average result of all

possible samples with a known probability. For example,

if we selected all possible samples and surveyed each of

these under essentially the same conditions and with the

same sample design, and if we calculated an estimate

and its standard error from each sample, then—

Approximately 90 percent of the intervals from

1.645 standard errors below the estimate to 1.645

standard errors above the estimate would include

the average result of all possible samples.

Approximately 95 percent of the intervals from

1.960 standard errors below the estimate to 1.960

standard errors above the estimate would include

the average result of all possible samples.

The average estimate derived from all possible samples

is or is not contained in any particular computed interval.

Table C-2. 1992 CPS Coverage Ratios

Age

Non-Black Black All persons

Males

Females MalesFemales MalesFemales Total

0-14 ....... 0.963 0.965 0.927 0.926 0.957 0.959 0.958

15 . . . . . . . . . 0.962 0.949 0.899 0.919 0.952 0.944 0.948

16 . . . . . . . . . 0.969 0.936 0.923 0.907 0.962 0.932 0.947

17 . . . . . . . . . 0.981 0.975 0.945 0.862 0.975 0.957 0.966

18 . . . . . . . . . 0.939 0.926 0.883 0.846 0.930 0.913 0.922

19 . . . . . . . . . 0.860 0.872 0.754 0.801 0.844 0.861 0.853

20-24 ...... 0.913 0.927 0.734 0.832 0.889 0.913 0.901

25-26 ...... 0.927 0.940 0.688 0.877 0.897 0.931 0.914

27-29 ...... 0.910 0.954 0.707 0.864 0.885 0.941 0.914

30-34 ...... 0.893 0.948 0.691 0.883 0.870 0.939 0.905

35-39 ...... 0.910 0.949 0.763 0.899 0.895 0.942 0.919

40-44 ...... 0.929 0.951 0.824 0.906 0.919 0.946 0.933

45-49 ...... 0.956 0.966 0.903 0.956 0.951 0.965 0.958

50-54 ...... 0.940 0.961 0.807 0.877 0.927 0.951 0.940

55-59 ...... 0.944 0.941 0.826 0.825 0.932 0.928 0.930

60-62 ...... 0.965 0.956 0.792 0.850 0.948 0.944 0.946

63-64 ...... 0.905 0.907 0.669 0.872 0.884 0.903 0.894

65-67 ...... 0.935 0.979 0.783 0.875 0.921 0.969 0.947

68-69 ...... 0.925 0.942 0.789 0.831 0.913 0.931 0.923

70-74 ...... 0.926 0.993 0.856 1.014 0.920 0.995 0.962

75-99 ...... 0.977 0.989 0.764 0.912 0.961 0.983 0.975

15+ . . . . . . . . 0.928 0.953 0.782 0.883 0.912 0.944 0.929

0+ . . . . . . . . . 0.936 0.955 0.827 0.895 0.923 0.947 0.935

C-3
However, for a particular sample, one can say with a

specified confidence that the confidence interval includes

the average estimate derived from all possible samples.

Hypothesis Testing. One may also use standard

errors for hypothesis testing. Hypothesis testing is a

procedure for distinguishing between population characteristics using sample estimates. The most common

type of hypothesis tested is (1) the population characteristics are identical versus (2) they are different. One

can perform tests at various levels of significance, where

a level of significance is the probability of concluding that

the characteristics are different when, in fact, they are

identical.

Unless noted otherwise, all statements of comparison

in the report passed a hypothesis test at the 0.10 level of

significance or better. This means that, for differences

cited in the report, the estimated absolute difference

between parameters is greater than 1.645 times the

standard error of the difference.

To perform the most common test, compute the

difference XA - XB, where XA and XB are sample

estimates of the characteristics of interest. A later section explains how to derive an estimate of the standard

error of the difference XA - XB. Let that standard error be

sDIFF. If XA - XB is between -1.645 times sDIFF and

+1.645 times sDIFF, no conclusion about the characteristics is justified at the 10 percent significance level. If,

on the other hand, XA - XB is smaller than -1.645 times

sDIFF or larger than +1.645 times sDIFF, the observed

difference is significant at the 10-percent level. In this

event, it is commonly accepted practice to say that the

characteristics are different. Of course, sometimes this

conclusion will be wrong. When the characteristics are,

in fact, the same, there is a 10-percent chance of

concluding that they are different.

Note that as we perform more tests, more erroneous

significant differences will occur. For example, at the

10-percent significance level, if we perform 100 independent hypothesis tests in which there are no real

differences, it is likely that about 10 erroneous differences will occur. Therefore, interpret the significance of

any single test cautiously.

Note Concerning Small Estimates and Small Differences. We show summary measures in the report only

when the base is 200,000 or greater. Because of the

large standard errors involved, there is little chance that

estimates will reveal useful information when computed

on a base smaller than 200,000. Also, nonsampling

error in one or more of the small number of cases

providing the estimate can cause large relative error in

that particular estimate. We show estimated numbers,

however, even though the relative standard errors of

these numbers are larger than those for the corresponding percentages. We provide smaller estimates primarily

to permit such combinations of the categories as serve

each user’s needs. Therefore, be careful in the interpretation of small differences since even a small amount of

nonsampling error can cause a borderline difference to

appear significant or not, thus distorting a seemingly

valid hypothesis test.

Standard Error Parameters and Tables and Their

Use. Most SIPP estimates have greater standard errors

than those obtained through a simple random sample

because we sampled clusters of living quarters for the

SIPP. To derive standard errors at a moderate cost and

applicable to a wide variety of estimates, we made a

number of approximations. We grouped estimates with

similar standard error behavior and developed two parameters (denoted ‘‘a’’ and ‘‘b’’) to approximate the standard

error behavior of each group of estimates. Because the

actual standard error behavior was not identical for all

estimates within a group, the standard errors we computed from these parameters provide an indication of the

order of magnitude of the standard error for any specific

estimate. These ‘‘a’’ and ‘‘b’’ parameters vary by characteristic and by demographic subgroup to which the

estimate applies. Use base ‘‘a’’ and ‘‘b’’ parameters

found in tables C-3 and C-4 for panel and calendar-year

estimates from the 1987 panel and the 1990 panel. Use

the parameters in tables C-5 and C-6 for annual estimates based on monthly averages from the 1987 and

1990 panels.

For users who wish further simplification, we also

provide general standard errors in tables C-7 and C-8.

Note that you need to adjust these standard errors by a

factor from tables C-3 through C-6. The standard errors

resulting from this simplified approach are less accurate.

Methods for using these parameters and tables for

computation of standard errors are given in the following

sections.

Methodology for Choosing the Correct Table for

Computation of Standard Errors. As mentioned earlier, this report uses both longitudinal and cross-sectional

estimates. It is important in calculating standard errors to

use the appropriate ‘‘a’’ and ‘‘b’’ parameters for the

estimate of interest.

The following information is for users who wish to

calculate standard errors for estimates given in the

report:

Estimate Use table(s):

Persons ever poor or persons

poor all of 2 years selected.

C-3,C-4

Average monthly poverty rate C-5,C-6

Median spell duration *

* The standard errors for these estimates have

already been calculated and are given in tables

C-9 and C-10.

C-4
Standard Errors of Estimated Numbers. There are

two ways to compute the approximate standard error, sx,

of an estimated number shown in this report. The first

uses the formula

sx 5 fs (1)

where f is a factor from tables C-3 through C-6, and s is

the standard error of the estimate obtained by interpolation from table C-7. Alternatively, approximate sx using

the formula,

sx 5 =ax2

1 bx (2)

from which we calculated the standard errors in table

C-7 . Here x is the size of the estimate and a and b are

the parameters in tables C-3 through C-6 associated

with the particular type of characteristic. Use of formula

2 will provide more accurate results than the use of

formula 1. When calculating standard errors for numbers

from crosstabulations involving different characteristics,

use the factor or set of parameters for the characteristic

that will give the largest standard error.

Illustration. Suppose the 1990 SIPP estimates that 31.8

million persons were poor in the average month of 1990.

The appropriate ‘‘a’’ and ‘‘b’’ parameters and the f factor

from table C-6, and the general standard error from table

C-7 are

a5 20.0000663 b 5 15,294 f 5 0.63 s 5 1,018,000

Using formula (1), the approximate standard error is

sx 5 0.63x 1,018,0005641,340

The 90-percent confidence interval is from 30,745,000

to 32,855,000. Using formula (2), the approximate standard error is

sx 5 =~20.0000663!~31,800,000!

2

1~15,294!~31,800,000! 5 648,000

The 90-percent confidence interval is from 30,734,000

to 32,866,000. Therefore, a conclusion that the average

estimate derived from all possible samples lies within a

range computed in this way would be correct for roughly

90 percent of all samples.

Standard Errors of Estimated Percentages. The

reliability of an estimated percentage, computed using

sample data for both numerator and denominator, depends

on the size of the percentage and its base. When the

numerator and denominator of the percentage have

different parameters, use the parameter (or appropriate

factor) from tables C-3 through C-6 indicated by the

numerator.

Calculate the approximate standard error, s(x,p), of an

estimated percentage p using the formula

s~x,p! 5 fs (3)

where p is the percentage of persons with a particular

characteristic such as the percent of persons receiving

housing assistance.

In this formula, f is the appropriate ‘‘f’’ factor from

tables C-3 through C-6, and s is the standard error of the

estimate obtained by interpolation from table C-8.

Alternatively, approximate it by the formula:

s~x,p! 5 Îb

x

~p!~1002 p! (4)

from which we calculated the standard errors in table

C-8 . Here x is the total number of persons in the base

of the percentage, p is the percentage (0 ≤ p ≤ 100), and

b is the ‘‘b’’ parameter in tables C-3 through C-6

associated with the characteristic in the numerator of the

percentage. Use of this formula will give more accurate

results than use of formula (3) above.

Illustration. Suppose the 1990 SIPP estimates that 4.5

percent of the population was poor each month of 1990

and 1991. The base for the percentage is 237,417,000.

The appropriate ‘‘b’’ parameter and ‘‘f’’ factor from table

C-4 and the appropriate general standard error from

table C-8 are

b 522,724 f 50.77 s5 0.3 percent

Using formula (3), the appropriate standard error is

sx 5 0.77 x 0.3 5 0.2 percent

Using formula (4), the approximate standard error is

sx 5 Î 22,724

237,417,000~4.5!~10024.5! 5 0.2 percent

The 90-percent confidence interval is from 4.2 to 4.8

percent. Therefore, a conclusion that the average percentage derived from all possible samples lies within a

range computed in this way would be correct for roughly

90 percent of all samples.

Standard Error of a Difference. The standard error of

a difference between two sample estimates, x and y, is

approximately equal to

s~x2y! 5 =sx

2

1sy

2

2 2rsxsy (9)

where sx and sy are the standard errors of the estimates

x and y and r is the correlation coefficient between the

characteristics estimated by x and y. The estimates can

C-5
be numbers, averages, percents, ratios, etc. Underestimates or overestimates of standard error of differences

result if the estimated correlation coefficient is overestimated or underestimated, respectively. In this report,

variances provided for differences in spell length contain

a nonzero correlation coefficient. For all other estimates,

we assume r is zero.

Illustration. Suppose the SIPP estimates that 9.1 percent of all persons who had not completed high school

were poor each month of 1990 and 1991 compared with

2.7 percent of high school graduates. The bases for

these percentages are 36,792,000 and 66,802,000,

respectively. The standard errors for these percentages

are computed using formula 4 to be 0.6 percent and 0.3

percent. Assuming that these two estimates are not

correlated, the standard error of the estimated difference

of 6.4 percentage points is

s~x2y! 5 =~0.6!

2

1~0.3!

2 5 0.7 percent

Suppose that it is desired to test at the 10-percent

significance level whether persons not completing high

school had higher poverty rates than high school graduates. To perform the test, compare the difference of 6.4

percent to the product 1.645 x 0.7=1.2 percent. Since

the difference is greater than 1.645 times the standard

error of the difference, the data show that the proportion

of high school graduates poor each month of 1990 and

1991 is less than that of persons not completing high

school.

C-6
Table C-3. SIPP Generalized Variance Parameters for Estimates from the 1987 Longitudinal Panel File

Characteristics of persons

Weights

1987 panel 1987 calendar year 1988 calendar year

ab f ab f ab f

Total or White*

18+ poverty................. - 0.0001807 30,767 0.90 - 0.0001685 28,695 0.87 - 0.0001719 29,290 0.88

All others ................... - 0.0001654 38,147 1.00 - 0.0001543 35,577 0.97 - 0.0001574 36,290 0.98

Black ........................ - 0.0005115 14,113 0.61 - 0.0004770 13,162 0.59 - 0.0004866 13,426 0.59

Table C-4. SIPP Generalized Variance Parameters for Estimates From the 1990 Longitudinal File

[Table revised since release of printed report]

Characteristics of persons

Weights

1990 panel 1990 calendar year 1991 calendar year

ab f ab f ab f

Total*

18+ poverty ................ - 0.0001077 18,329 0.69 - 0.0000965 16,418 0.66 - 0.0001002 17,051 0.67

All others .................. - 0.0000985 22,724 0.77 - 0.0000882 20,356 0.73 - 0.0000916 21,140 0.74

White........................ - 0.0001093 25,185 0.81 - 0.0000979 22,560 0.77 - 0.0001016 23,429 0.78

Black ........................ - 0.0004066 11,300 0.54 - 0.0003642 10,122 0.52 - 0.0003782 10,512 0.52

Hispanic ..................... - 0.0000778 13,256 0.58 - 0.0000697 11,874 0.56 - 0.0000724 12,332 0.57

* Use the ′′All others′′ parameter for 0+ poverty and any other type of tabulation not covered by the characteristic ′′18+ poverty.′′

Table C-5. SIPP Indirect Generalized Variance Parameters for Annual Estimates Based on Monthly

Averages from the 1987 Cross-Sectional Files

Characteristics of persons

1987 calendar year 1988 calendar year

ab fab f

Total or White

18+ poverty.............................. - 0.0001286 21,888 0.76 - 0.0001401 23,857 0.79

All others ................................ - 0.0001177 27,137 0.84 - 0.0001283 29,579 0.88

Black ..................................... - 0.0003639 10,040 0.51 - 0.0003967 10,944 0.54

Table C-6. SIPP Indirect Generalized Variance Parameters for Annual Estimates Based on Averages From

the 1990 Cross-Sectional Files

[Table revised since release of printed report]

Characteristics of persons

1990 calendar year 1991 calendar year

ab fab f

Total

18+ poverty.............................. - 0.0000725 12,336 0.57 - 0.0000790 13,446 0.59

All others................................ - 0.0000663 15,294 0.63 - 0.0000723 16,671 0.66

White ..................................... - 0.0000735 16,951 0.67 - 0.0000801 18,476 0.70

Black ..................................... - 0.0002737 7,605 0.45 - 0.0002983 8,289 0.47

Hispanic................................... - 0.0000524 8,922 0.48 - 0.0000571 9,725 0.50

C-7
Table C-7. Standard Errors of Estimated Numbers of Persons

[Numbers in thousands]

Size of estimate Standard error Size of estimate Standard error

200 . . . . . . . . . . . . . . . . . . . . . . . . . . 87 50,000 ......................... 1,222

300 . . . . . . . . . . . . . . . . . . . . . . . . . . 107 80,000 ......................... 1,412

600 . . . . . . . . . . . . . . . . . . . . . . . . . . 151 100,000 ........................ 1,470

1,000 . . . . . . . . . . . . . . . . . . . . . . . . 195 130,000 ........................ 1,471

2,000 . . . . . . . . . . . . . . . . . . . . . . . . 275 140,000 ........................ 1,449

3,000 . . . . . . . . . . . . . . . . . . . . . . . . 336 150,000 ........................ 1,414

5,000 . . . . . . . . . . . . . . . . . . . . . . . . 432 200,000 ........................ 1,007

8,000 . . . . . . . . . . . . . . . . . . . . . . . . 543 220,000 . . . . . . . . . . . . . . . . . . . . . . . . 622

11,000 . . . . . . . . . . . . . . . . . . . . . . . 632 230,000 . . . . . . . . . . . . . . . . . . . . . . . . 155

13,000 . . . . . . . . . . . . . . . . . . . . . . . 684

15,000 . . . . . . . . . . . . . . . . . . . . . . . 731

17,000 . . . . . . . . . . . . . . . . . . . . . . . 775

22,000 . . . . . . . . . . . . . . . . . . . . . . . 871

26,000 . . . . . . . . . . . . . . . . . . . . . . . 938

30,000 . . . . . . . . . . . . . . . . . . . . . . . 998

Table C-8. Standard Errors of Estimated Percentages of Persons

Base of estimated percentage (thousands) ≤ 1 or ≤ 99 2 or 98 5 or 95 10 or 90 25 or 75 50

200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 6.1 9.5 13.1 18.9 21.8

300 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 5.0 7.8 10.7 15.4 17.6

600 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 3.5 5.5 7.6 10.9 12.6

1,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9 2.7 4.3 5.9 8.5 9.8

2,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 1.9 3.0 4.1 6.0 6.9

3,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 1.6 2.5 3.4 4.9 5.6

5,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 1.2 1.9 2.6 3.8 4.4

8,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.7 1.0 1.5 2.1 3.0 3.5

11,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 0.8 1.3 1.8 2.5 2.9

13,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 0.8 1.2 1.6 2.3 2.7

15,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 0.7 1.1 1.5 2.2 2.5

17,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 0.7 1.0 1.4 2.1 2.4

22,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 0.6 0.9 1.2 1.8 2.1

26,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 0.5 0.8 1.1 1.7 1.9

30,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 0.5 0.8 1.1 1.5 1.8

50,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 0.4 0.6 0.8 1.2 1.4

80,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 0.3 0.5 0.7 0.9 1.1

100,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 0.3 0.4 0.6 0.8 1.0

130,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 0.2 0.4 0.5 0.7 0.9

140,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 0.2 0.4 0.5 0.7 0.8

150,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 0.2 0.3 0.5 0.7 0.8

200,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 0.2 0.3 0.4 0.6 0.7

220,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 0.2 0.3 0.4 0.6 0.7

230,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 0.2 0.3 0.4 0.6 0.6

235,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 0.2 0.3 0.4 0.6 0.6

240,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 0.2 0.3 0.4 0.5 0.6

C-8
Table C-9. Standard Errors of Survival Rates and Median Spell Durations for Persons Who Became Poor

During the 1990 SIPP Panel, by Selected Characteristics

Characteristic

Standard errors of survival rates for program spells after- Standard

error of

median

spell

duration

1

month

4

months

8

months

12

months

16

months

20

months

24

months

28

months

All spells ....................... 0.00000 0.01258 0.01220 0.01162 0.01142 0.01142 0.01181 0.01258 0.22459

Race and Hispanic Origin

White .......................... 0.00000 0.01511 0.01429 0.01348 0.01307 0.01307 0.01368 (B) 0.07963

Not of Hispanic origin1 ......... 0.00000 0.01637 0.01536 0.01434 0.01374 0.01374 0.01414 (B) 0.08486

Black........................... 0.00000 0.02034 0.02088 0.02061 0.02048 0.02048 0.02170 (B) 0.58446

Hispanic origin .................. 0.00000 0.02462 0.02477 0.02401 0.02370 0.02416 (B) (B) 0.32364

Not of Hispanic origin ............ 0.00000 0.01366 0.01308 0.01251 0.01212 0.01212 0.01251 0.01328 0.06735

Age

Under 18 years.................. 0.00000 0.02157 0.02099 0.02021 0.02001 0.02001 0.02079 (B) 0.34977

18 to 64 years .................. 0.00000 0.01440 0.01388 0.01318 0.01266 0.01266 0.01318 (B) 0.07458

65 years and over ............... 0.00000 0.04663 0.04812 0.04762 0.04829 0.04862 (B) (B) 1.65936

Sex

Male ........................... 0.00000 0.01825 0.01748 0.01651 0.01592 0.01592 0.01670 (B) 0.09321

Female ......................... 0.00000 0.01738 0.01700 0.01622 0.01603 0.01603 0.01680 (B) 0.30515

Educational Attainment (persons 18 years and over)

Less than 4 years of high

school......................... 0.00000 0.02487 0.02540 0.02505 0.02505 0.02540 0.02645 (B) 0.60601

High school graduate, no college . . 0.00000 0.02202 0.02099 0.02013 0.01961 0.01927 0.01961 (B) 0.10666

1 or more years of college ........ 0.00000 0.02443 0.02241 0.01972 0.01837 0.01837 (B) (B) 0.12133

Disability Status (persons 15 to

69 years)

With a work disability ............ 0.00000 0.03429 0.03467 0.03390 0.03371 0.03429 0.03602 (B) 0.76085

With no work disability ........... 0.00000 0.01695 0.01618 0.01502 0.01444 0.01425 0.01502 (B) 0.08666

Residence

Metropolitan .................... 0.00000 0.01488 0.01450 0.01373 0.01335 0.01335 0.01411 (B) 0.07630

Central city ................... 0.00000 0.02129 0.02091 0.02014 0.01976 0.01957 0.02014 (B) 0.38939

Non-central city ............... 0.00000 0.02066 0.01936 0.01806 0.01750 0.01769 0.01899 (B) 0.10239

Nonmetropolitan ................. 0.00000 0.02300 0.02260 0.02161 0.02121 0.02121 0.02181 (B) 0.41435

Region

Northeast....................... 0.00000 0.03070 0.02828 0.02717 0.02661 0.02624 (B) (B) 0.12840

Midwest ........................ 0.00000 0.02555 0.02458 0.02342 0.02284 0.02284 0.02381 (B) 0.12388

South .......................... 0.00000 0.01994 0.01974 0.01897 0.01839 0.01839 0.01916 (B) 0.36002

West ........................... 0.00000 0.02827 0.02709 0.02572 0.02532 0.02532 0.02709 (B) 0.42991

Family Status

In families ...................... 0.00000 0.01391 0.01353 0.01275 0.01256 0.01237 0.01295 0.01333 0.24348

In families with related

children under 18 years ...... 0.00000 0.01532 0.01493 0.01416 0.01396 0.01396 0.01435 0.01493 0.25405

In married-couple families ...... 0.00000 0.01664 0.01528 0.01432 0.01374 0.01354 0.01335 (B) 0.08319

In married-couple families

with related children under 18

years....................... 0.00000 0.01843 0.01707 0.01610 0.01571 0.01533 0.01513 (B) 0.09700

In families with a female

householder, no spouse

present.................... 0.00000 0.02534 0.02665 0.02646 0.02646 0.02702 0.02926 (B) 0.68953

In families with a female

householder, no spouse

present, with relatedchildren under 18 years ..... 0.00000 0.02704 0.02853 0.02835 0.02853 0.02909 0.03170 (B) 0.85595

Unrelated individuals ............. 0.00000 0.02784 0.02746 0.02634 0.02616 0.02653 (B) (B) 0.53060

In non-family households ....... 0.00000 0.02924 0.02887 0.02775 0.02738 0.02775 (B) (B) 0.57367

See footnotes at end of table.

C-9
Table C-9. Standard Errors of Survival Rates and Median Spell Durations for Persons Who Became Poor

During the 1990 SIPP Panel, by Selected Characteristics—Continued

Characteristic

Standard errors of survival rates for program spells after- Standard

error of

median

spell

duration

1

month

4

months

8

months

12

months

16

months

20

months

24

months

28

months

Employment and Labor Force

Status (persons 18 years and

over)

Employed full-time ............... 0.00000 0.02215 0.02069 0.01955 0.01906 0.01873 0.01938 (B) 0.10914

Employed part-time .............. 0.00000 0.03066 0.02879 0.02597 0.02441 0.02409 (B) (B) 0.50219

Unemployed .................... 0.00000 0.03233 0.03174 0.02938 0.02819 0.02819 (B) (B) 0.51222

Not in labor force ................ 0.00000 0.02123 0.02139 0.02091 0.02075 0.02075 0.02171 (B) 0.45032

Marital Status (persons 18 years

and over)

Married......................... 0.00000 0.01975 0.01819 0.01698 0.01628 0.01594 0.01611 (B) 0.09355

Separated, divorced, or widowed . . 0.00000 0.02830 0.02864 0.02830 0.02813 0.02847 0.03000 (B) 0.56432

Never married................... 0.00000 0.02554 0.02520 0.02367 0.02316 0.02316 0.02435 (B) 0.47506

Family Size

1 person (unrelated individual) .... 0.00000 0.02784 0.02746 0.02634 0.02616 0.02653 (B) (B) 0.53060

2 persons....................... 0.00000 0.03049 0.02940 0.02796 0.02706 0.02724 0.02796 (B) 0.71074

3 persons....................... 0.00000 0.02969 0.02861 0.02699 0.02573 0.02519 (B) (B) 0.46604

4 persons....................... 0.00000 0.02664 0.02495 0.02327 0.02252 0.02195 0.02289 (B) 0.15948

5 persons....................... 0.00000 0.03068 0.02958 0.02903 0.02866 0.02848 (B) (B) 0.14146

6 or more persons ............... 0.00000 0.03263 0.03244 0.03089 0.03089 0.03108 0.03128 (B) 0.40545

Access to Health Insurance

Covered by health insurance...... 0.00000 0.01489 0.01434 0.01342 0.01324 0.01324 0.01379 (B) 0.07355

Private insurance .............. 0.00000 0.01664 0.01484 0.01339 0.01266 0.01230 0.01230 (B) 0.07418

Medicare ..................... 0.00000 0.04766 0.04986 0.04986 0.05060 0.05133 (B) (B) 2.14489

Medicaid ..................... 0.00000 0.02795 0.03139 0.03248 0.03339 0.03484 0.03629 (B) 0.90005

Not covered by health insurance . . 0.00000 0.02026 0.02007 0.01932 0.01894 0.01894 0.01969 (B) 0.36759

Receipt of Public Assistance

Received public assistance2 ...... 0.00000 0.02268 0.02471 0.02489 0.02563 0.02655 0.02766 (B) 0.61954

Did not receive public assistance . . 0.00000 0.01413 0.01300 0.01206 0.01131 0.01112 0.01131 (B) 0.06596

B Base less than 200,000.

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

C-10
Table C-10. Standard Errors of Survival Rates and Median Spell Durations for Persons Who Became Poor

During the 1987 SIPP Panel, by Selected Characteristics

Characteristic

Standard errors of survival rates for program spells after- Standard

error of

median

spell

duration

1

month

4

months

8

months

12

months

16

months

20

months

24

months

All spells ................................ 0.00000 0.01757 0.01732 0.01635 0.01586 0.01635 0.01854 0.09027

Race and Hispanic Origin

White .................................... 0.00000 0.02001 0.01929 0.01808 0.01712 0.01712 (B) 0.10127

Not of Hispanic origin1 ................... 0.00000 0.02142 0.02046 0.01902 0.01805 0.01805 (B) 0.11313

Black .................................... 0.00000 0.02490 0.02552 0.02521 0.02536 0.02583 (B) 0.39679

Hispanic origin ............................ 0.00000 0.05143 0.05167 0.04997 0.04803 (B) (X) 0.83206

Not of Hispanic origin ...................... 0.00000 0.01880 0.01831 0.01709 0.01684 0.01709 0.01929 0.10009

Age

Under 18 years ........................... 0.00000 0.03107 0.03107 0.03008 0.02959 0.03107 (B) 0.63375

18 to 64 years ............................ 0.00000 0.02004 0.01916 0.01764 0.01699 0.01720 (B) 0.10236

65 years and over ......................... 0.00000 0.06047 0.06335 0.06438 0.06561 0.06561 (B) 2.67385

Sex

Male ..................................... 0.00000 0.02580 0.02457 0.02309 0.02236 0.02309 (B) 0.12775

Female................................... 0.00000 0.02401 0.02401 0.02304 0.02255 0.02304 (B) 0.46074

Educational Attainment (persons 18 years

and over)

Less than 4 years of high school ............ 0.00000 0.03359 0.03446 0.03381 0.03359 0.03467 (B) 0.56778

High school graduate, no college............ 0.00000 0.03047 0.02918 0.02637 0.02486 0.02486 (B) 0.14481

1 or more years of college.................. 0.00000 0.03472 0.03043 0.02764 0.02679 (B) (B) 0.16715

Disability Status (persons 15 to 69 years)

With a work disability ...................... 0.00000 0.04901 0.04926 0.04780 0.04756 0.04926 (B) 1.31030

With no work disability ..................... 0.00000 0.02358 0.02212 0.02042 0.01944 0.01969 (B) 0.12153

Residence

Metropolitan .............................. 0.00000 0.02070 0.01974 0.01854 0.01805 0.01854 (B) 0.10110

Central city ............................. 0.00000 0.02910 0.02766 0.02646 0.02622 0.02694 (B) 0.13230

Non-central city ......................... 0.00000 0.02921 0.02801 0.02538 0.02394 0.02490 (B) 0.15324

Nonmetropolitan........................... 0.00000 0.03283 0.03357 0.03259 0.03209 0.03234 (B) 0.72577

Region

Northeast................................. 0.00000 0.04385 0.04337 0.04217 0.04144 0.04193 (B) 0.19758

Midwest .................................. 0.00000 0.03612 0.03512 0.03362 0.03263 0.03338 (B) 0.18929

South .................................... 0.00000 0.02837 0.02884 0.02717 0.02670 0.02694 (B) 0.48627

West..................................... 0.00000 0.03694 0.03327 0.03107 0.02960 0.03131 (B) 0.16880

Family Status

In families ................................ 0.00000 0.01957 0.01908 0.01786 0.01737 0.01786 (B) 0.10031

In families with related

children under 18 years ................ 0.00000 0.02164 0.02140 0.02017 0.01968 0.02041 (B) 0.11560

In married-couple families ................ 0.00000 0.02322 0.02175 0.01980 0.01906 0.01906 (B) 0.10999

In married-couple families with

related children under 18 years ....... 0.00000 0.02640 0.02467 0.02221 0.02147 0.02147 (B) 0.12830

In families with a female householder,

no spouse present..................... 0.00000 0.03433 0.03786 0.03810 0.03880 0.03998 (B) 0.71487

In families with a female householder,

no spouse present, with related

children under 18 years .............. 0.00000 0.03671 0.04092 0.04185 0.04255 0.04466 (B) 0.84874

Unrelated individuals....................... 0.00000 0.04072 0.04025 0.03885 0.03814 0.03838 (B) 0.63887

In non-family households ................. 0.00000 0.04190 0.04167 0.04026 0.03980 0.04050 (B) 0.70228

See footnotes at end of table.

C-11
Table C-10. Standard Errors of Survival Rates and Median Spell Durations for Persons Who Became Poor

During the 1987 SIPP Panel, by Selected Characteristics—Continued

Characteristic

Standard errors of survival rates for program spells after- Standard

error of

median

spell

duration

1

month

4

months

8

months

12

months

16

months

20

months

24

months

Employment and Labor Force Status

(persons 18 years and over)

Employed full-time......................... 0.00000 0.03175 0.02903 0.02527 0.02402 (B) (B) 0.16919

Employed part-time........................ 0.00000 0.04479 0.04316 0.03970 0.03746 (B) (B) 0.19950

Unemployed .............................. 0.00000 0.04917 0.04878 0.04545 0.04074 0.04055 (B) 0.90892

Not in labor force.......................... 0.00000 0.02883 0.02863 0.02802 0.02802 0.02904 (B) 0.66054

Marital Status (persons 18 years and over)

Married .................................. 0.00000 0.02706 0.02488 0.02248 0.02160 0.02138 (B) 0.13311

Separated, divorced, or widowed............ 0.00000 0.03712 0.03859 0.03775 0.03712 0.03754 (B) 0.76541

Never married ............................ 0.00000 0.03749 0.03620 0.03469 0.03404 0.03447 (B) 0.18961

Family Size

1 person (unrelated individual) .............. 0.00000 0.04072 0.04025 0.03885 0.03814 0.03838 (B) 0.63887

2 persons ................................ 0.00000 0.03993 0.04039 0.03788 0.03674 0.03697 (B) 0.63435

3 persons ................................ 0.00000 0.04057 0.04011 0.03596 0.03411 0.03411 (X) 0.82747

4 persons ................................ 0.00000 0.03680 0.03395 0.03181 0.03158 (B) (X) 0.18281

5 persons ................................ 0.00000 0.04541 0.04278 0.04039 0.03991 0.04087 (B) 0.20554

6 or more persons......................... 0.00000 0.04857 0.04955 0.04955 0.04906 (B) (X) 0.77758

Access to Health Insurance

Covered by health insurance ............... 0.00000 0.02153 0.02084 0.01991 0.01968 0.02060 (B) 0.10418

Private insurance........................ 0.00000 0.02407 0.02175 0.01967 0.01898 0.01921 (B) 0.10877

Medicare ............................... 0.00000 0.06317 0.06547 0.06570 0.06684 0.06776 (B) 1.74347

Medicaid ............................... 0.00000 0.03987 0.04685 0.05023 0.05383 0.06352 (B) 4.32466

Not covered by health insurance ............ 0.00000 0.02724 0.02700 0.02487 0.02416 0.02345 (B) 0.37661

Receipt of Public Assistance

Received public assistance2 ................ 0.00000 0.03231 0.03623 0.03785 0.03900 0.04246 (B) 1.22085

Did not receive public assistance............ 0.00000 0.01973 0.01804 0.01588 0.01515 0.01515 (B) 0.09382

B Base less than 200,000. X Not applicable.

1

Persons of Hispanic origin may be of any race

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

C-12
Appendix D. Description of SIPP 1990 Panel File and Data

Quality

DESCRIPTION OF SIPP 1990 PANEL FILE

The estimates presented in this report are based on

the SIPP 1990 panel file. This file contains monthly data

for persons over a 32-month period. The staggered

SIPP design (described in appendix A) means that the

actual reference periods are October 1989 to May 1992,

November 1989 to June 1992, December 1989 to July

1992, and January 1990 to August 1992. The period

covered by the 1990 longitudinal panel file consists of 32

interview months (eight interviews) for rotations 1, 2, 3,

and 4. Data from all four rotation groups are available

only for the reference period January 1990 through May

1992.

ATTRITION BIAS

Each person in the panel file has been assigned three

weights: a weight for calendar year 1990, a weight for

calendar year 1991, and a weight for the 32-month

reference period.1 In order to receive a non-zero weight,

a person must have an observation for each month of

the relevant reference period or have a complete set of

observations up until the time he or she died, became

institutionalized, or moved to Armed Forces barracks or

out of the country. The data shown in this report are

affected if characteristics of persons with an incomplete

set of observations differed from those with a complete

set.

Table D-1 shows three categories of sample persons

by sex, age, and program participation status. The

numbers in the table are unit counts; they are not

weighted. The category ‘‘complete set of interviews

obtained’’ includes 43,799 persons. The next category,

‘‘Interviewed in first wave, left sample for reasons other

than death, institutionalization, or a move to Armed

Forces barracks or out of the country’’ includes 14,489

persons. The final category includes 10,827 persons

who were not members of a SIPP household during the

first wave of interviews, but who subsequently became

members of a sample household.

A comparison of the first two columns shows that the

characteristics of those who completed the full set of

interviews are reasonably close to the characteristics of

those who dropped out of the sample. The major

differences in the age distribution are for young adults

and for the elderly. Young adults are underrepresented

and the elderly are overrepresented in the group of

persons who completed the full set of interviews. The

data in table D-1 are, as noted, unweighted, and any

potential problem caused by unrepresentative age distributions are minimized when the file is weighted to

independent controls.

TIME-IN-SAMPLE BIAS

The use of the panel file to obtain estimates for 1990

and 1991 raises the issue of time-in-sample bias. There

is ample evidence that certain measures vary according

to the number of times the respondent has been visited.

In the CPS, for example, the measured unemployment

rate is always higher for the group of households being

interviewed for the first time than for the groups being

interviewed for the second or later times.

Time-in-sample bias arises when a person’s response

to a survey question (or the interviewer’s method of

asking a question) is influenced by what occurred in a

previous visit. The overlapping SIPP sample design

provides the data that allows for an examination of the

presence of time-in-sample bias in SIPP estimates. That

is, it is possible in SIPP to obtain estimates for a given

time period from two or more separate panels and the

amount of time respondents will have spent in the SIPP

panel will differ for each of the panels. For example,

estimates for each of the four quarters of 1991 can be

obtained from both the 1990 and 1991 panels (respondents in the 1990 panel will have had more visits).

Quarterly estimates for the years 1984 to 1992 are

shown in table D-2. Estimates from each panel file are

shown separately for comparison. The estimates shown

are the number of poor nonfarm households as well as

the number of households receiving various government

benefits.

The figures in table D-2 provide very little evidence

regarding the existence of time-in-sample bias for several reasons. First, most of the observed differences are

smaller than the differences that could be explained by

sampling error. Second, a single observation is not

sufficient to identify a pattern of bias. Third, differences

may be attributable to attrition bias rather than time-insample bias. In spite of these qualifications, however,

1

The panel file does not contain month weights. Month weights

necessary for cross-sectional estimates were extracted from the wave

files.

D-1
the observed relationships offer some reason to be

cautious in interpreting the differences between the

1990 and 1991 estimates that have been presented

earlier in this report.

OTHER ISSUES OF DATA QUALITY

Two major determinants of the quality of income data

collected in household surveys are the magnitude of

missing responses and the accuracy of the responses

that are provided. This appendix has been included to

supply information concerning nonresponse rates for

selected income questions, the average amounts of

income reported in the survey or assigned in the imputation of missing responses, and the extent to which the

survey figures underestimate numbers of income recipients and amounts of income received.

Nonresponse in this discussion refers to missing

responses to specific questions or ‘‘items’’ on the questionnaire. Noninterviews or complete failure to obtain

cooperation from any household member have not been

considered in this examination of nonresponse rates.

Adjustments to account for noninterviews are made by

proportionally increasing the survey weights of interviewed households. Missing responses to specific questions are assigned a value in the imputation phase of the

data processing operation.

Nonresponse is a very important factor in assessing

the quality of survey data. Nonresponses to income

questions cannot be considered random since experience has shown that persons with the highest nonresponse rates have reported characteristics such as

education levels and occupations that, in general, differ

from population averages. The most frequent causes of

nonresponse are the inability of the respondent to

answer the question because of either a 1) lack of

knowledge or 2) refusal to answer. The first reason is

especially important in situations of proxy response

when one household member answers questions for

another household member not present at the time of

the interview. The practice of accepting proxy interviews

from household members deemed ‘‘qualified’’ to answer

is a standard procedure in the CPS and most other

surveys conducted by the Bureau. During the eight

interviews of the 1990 panel, an average of 36 percent

of the interviews were taken from proxy respondents.

Nonresponses are assigned values prior to producing

estimates from the survey data. The procedure used to

assign or impute responses for missing data for SIPP

are of a type commonly referred to as a ‘‘hot deck’’

imputation method. This process assigns values reported

in the survey by respondents to nonrespondents. The

respondent from whom the value is taken is termed the

‘‘donor.’’ Values from donors are stored in a matrix

defined by demographic and economic data available

for both donors and nonrespondents. Each cell of the

matrix defines a unique combination of demographic

and economic characteristics. For example, the imputation of an amount for monthly wage and salary income is

based on eight different variables. These were 1)occupation, 2)sex, 3)age, 4)race, 5)educational attainment,

6)weeks worked, 7)usual hours worked per week, and

8)place of residence.

The second important determinant of data quality and

probably the one examined most closely by users of the

income data collected in household surveys is the

accuracy of reported (and imputed) amounts. In general,

household surveys have a tendency to underestimate

the number of persons receiving income and the average amount received. These problems result for a

variety of reasons including random response error,

misreporting of sources of income, failure to report the

receipt of income from a specified source, and failure to

report the full amount received. The net effect of these

kinds of problems is, for most income types, underestimation or underreporting of income amounts. The extent

of underreporting is measured by comparing survey

estimates with independently derived estimates, usually

based on administrative data that are, generally, more

reliable than the estimates derived from the survey. It

should be noted that the independent estimates are

subject to errors themselves. In addition, independent

estimates do not reflect income attributable to the ‘‘underground’’ economy, some of which may be reported in the

survey.2 AFDC and food stamp participation for January

1992 were 25.3 and 23.4 percent lower in the 1990 SIPP

panel than the numbers from administrative records of

the Departments of Health and Human Services and

Agriculture.

COMPUTATION OF POVERTY STATUS IN

SIPP AND COMPARISON WITH CPS

ESTIMATES

Official poverty data in the CPS are based on questions on income received in the preceding calendar year

which are asked in the March supplement. Family

composition is fixed as of the survey date and assumed

to be constant over the previous year (in the case of

1990 poverty status, the data were collected in March

1991). In this report using the 1990 SIPP panel, income

information was collected for each month. Family composition data was updated on a monthly basis also. A

2

For a general discussion of these problems, see Thomas B.

Jabine, Karen F. King, and Rita J. Petroni, SIPP Quality Profile,

Bureau of the Census, May 1990, pp.145-146. For a more specific

discussion of the quality of the income data from the SIPP, see Denton

R. Vaughn, ‘‘Reflections on the Income Estimates from the Initial

Panel of the Survey of Income and Program Participation,’’ in Individuals and Families in Transition: Understanding Change Through Longitudinal Data, U.S. Department of Commerce, Bureau of the Census,

March 1988, pp. 333-413. The Census Bureau is currently updating

this evaluation with an analysis of the income data from the SIPP 1990

panel.

D-2
person’s annual poverty status was determined by comparing the sum of the person’s monthly income (family

income or unrelated individual income as appropriate)

against the sum of the appropriate monthly poverty

thresholds. If the sum of the monthly incomes was below

the sum of the monthly poverty thresholds, the person

was classified as below the poverty level for the year.

Poverty estimates vary considerably between the

CPS and SIPP. In 1990, the CPS based poverty rate

was 13.5 percent, compared to 10.3 percent based on

SIPP. When household composition was fixed as of

March of 1991, in order to make the SIPP estimate more

comparable to the CPS estimate, the poverty rate rose

to 10.8 percent, still significantly less than the CPS rate.

Other than treatment of changes in household composition, there are several other differences between

CPS and SIPP that should be noted in comparing results

from the two surveys. First, the shorter recall period in

SIPP results in more accurate data on the receipt of

transfer income. This difference would tend to result in

SIPP poverty estimates that are lower than CPS poverty

estimates. A second difference concerns the way in

which self-employment income is recorded. It is possible

to record negative amounts in CPS, but not in SIPP. This

difference would also tend to result in SIPP estimates of

poverty that are lower than CPS estimates. It is also

possible because of its more frequent interviews that

SIPP has better reporting of intermittent income than

does the CPS. If such income tends to cluster at the

lower end of the earnings distribution, this would tend to

lower the number of poor.

Paradoxically, wage and salary income estimates

tend to be lower in SIPP than in the CPS. It is possible

that persons tend to report net rather than gross wage

and salary income in the SIPP. This would tend to result

in SIPP estimates of poverty that are higher than the

CPS estimates for those persons/families with wage and

salary income.

Tables D-3 and D-4 compare selected poverty rates

and year-to-year changes in these rates from the March

1991 and 1992 CPS (in which 1990 and 1991 poverty

statistics were collected) with the 1990 SIPP panel file

figures. In general, SIPP estimates are considerably

lower, with the CPS poverty rate for 1990 being over

three percentage points greater than the comparable

SIPP estimate.

The total weighted number of persons in 1990 will fall

short of the independent estimates of the total population because some persons with positive weights are

excluded from the analysis, namely, those who died,

were institutionalized, or moved to Armed Forces barracks or out of the country. The total estimate for 1991

will fall short of independent estimates for the same

reasons and because of natural increase and net migration between 1990 and 1991.

D-3
Table D-1. Percent Distribution: Three Categories of Sample Persons: 1990 SIPP Panel

Characteristic

Complete set of interviews obtained1

Interviewed in first

wave, left sample for

reasons other than

death, institutionalization, or move to

Armed Forces barracks or out of the

country

Not a member of

sample household during first wave, interview obtained in second or later waves

Total ........................................................... 43,799 14,489 10,827

(100.0) (100.0) (100.0)

Sex

Male ......................................................... 47.0 50.4 51.0

Female ....................................................... 53.0 49.6 49.0

Age at First Interview

Under 18 years ................................................ 28.6 27.4 38.0

Under 6 years ............................................... 10.7 9.4 25.1

18 to 24 years. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.6 15.6 20.8

25 to 44 years................................................. 31.5 33.3 27.5

45 to 64 years................................................. 18.6 16.5 10.4

65 years and over ............................................. 12.7 7.3 3.2

75 years and over . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 2.6 1.1

Program participation, first month in sample:

Persons 18 years and over ..................................... 31,267 10,523 6,711

(100.0) (100.0) (100.0)

Participated in major assistance program . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 10.5 11.4

AFDC or general assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 2.9 2.7

Food stamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 5.1 5.8

Medicaid. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 5.9 7.1

Public/subsidized housing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9 4.8 2.8

SSI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 1.8 2.2

Did not participate ............................................. 90.9 89.5 88.6

Covered by private health insurance ............................. 79.7 70.2 67.9

Provided through employer ................................... 44.2 39.2 39.5

Not covered by private health insurance .......................... 20.4 29.8 32.1

1

Includes 10,832 persons who died, were institutionalized, or moved to Armed Forces barracks or out of the country during the 32-month period.

D-4
Table D-2. Average Monthly Nonfarm Poverty and Household Participation in Means-Tested and

Nonmeans-Tested Government Programs—SIPP Panels: First Quarter 1984

to Fourth Quarter 1993

[In thousands]

Panel, year, and quarter

All

households

Nonfarm

poor

households

Received

Government

benefits

Received

meanstested

benefits

Received

AFDC

or other

nonSSI

public

assistance

Received

SSI

Received

food

stamps

Covered by

Medicaid

Lived in

public

or subsidized

housing

Received

nonmeanstested

benefits

Received

Social

Security or

RR

Received

unemployment

compensation

1984 Panel

1984: 1st quarter....... 83,643 11,722 39,050 16,052 3,870 2,880 6,462 7,593 3,615 30,578 23,479 2,659

2nd quarter ...... 84,002 11,124 37,712 14,460 3,832 2,975 6,303 7,559 3,669 29,973 23,525 2,047

3rd quarter ...... 84,609 11,050 36,674 13,188 3,565 3,002 5,989 7,242 3,670 29,747 23,475 1,784

4th quarter....... 84,945 11,160 38,347 15,276 3,585 3,008 6,107 7,211 3,584 30,308 23,559 2,240

1985: 1st quarter....... 84,948 10,922 39,158 15,403 3,763 3,020 6,230 7,458 3,546 31,238 23,821 2,944

2nd quarter ...... 85,614 10,783 37,725 13,921 3,651 3,085 5,955 7,264 3,486 30,485 23,955 2,062

3rd quarter ...... 86,249 10,872 37,143 13,013 3,598 3,036 5,886 7,370 3,502 30,339 23,938 1,757

4th quarter....... 86,585 10,688 38,547 15,274 3,622 3,064 5,839 7,461 3,583 30,379 23,864 1,824

1985 Panel

1985: 1st quarter....... 85,228 11,585 (NA) (NA) 3,536 2,990 5,999 7,277 3,751 (NA) 23,559 2,872

2nd quarter ...... 85,875 10,929 (NA) (NA) 3,554 3,116 5,808 7,460 3,778 (NA) 23,781 2,232

3rd quarter ...... 86,561 11,088 (NA) (NA) 3,526 3,211 5,624 7,501 3,844 (NA) 23,838 1,883

4th quarter....... 86,832 10,978 (NA) (NA) 3,499 3,200 5,676 7,517 3,889 (NA) 23,929 2,075

1986: 1st quarter....... 86,911 10,890 (NA) (NA) 3,591 3,114 5,800 7,589 3,868 (NA) 24,145 2,617

2nd quarter ...... 86,940 10,463 (NA) (NA) 3,502 3,168 5,617 7,456 3,847 (NA) 24,130 2,112

3rd quarter ...... 87,180 10,873 (NA) (NA) 3,462 3,201 5,573 7,499 3,813 (NA) 24,150 2,037

4th quarter....... 87,607 10,872 (NA) (NA) 3,516 3,181 5,641 7,575 3,710 (NA) 24,264 2,206

1986 Panel

1986: 1st quarter....... 87,134 11,711 40,711 16,422 3,753 3,107 6,588 7,593 4,172 31,702 24,013 2,443

2nd quarter ...... 87,192 11,185 40,125 16,034 3,858 3,270 6,524 7,901 4,347 31,272 24,102 2,001

3rd quarter ...... 87,313 11,144 39,427 14,999 3,680 3,290 6,180 7,879 4,239 31,448 24,310 2,062

4th quarter....... 87,721 11,081 40,620 16,418 3,780 3,270 6,212 8,041 4,199 31,697 24,523 1,985

1987: 1st quarter....... 88,118 11,471 41,243 16,654 3,885 3,347 6,340 8,265 4,172 32,268 24,567 2,356

2nd quarter ...... 88,367 11,022 39,781 15,123 3,848 3,395 6,218 8,278 4,179 31,619 24,612 1,720

3rd quarter ...... 88,645 10,839 39,358 14,975 3,794 3,482 5,900 8,288 4,204 31,067 24,572 1,442

4th quarter....... 89,058 10,634 40,846 16,431 3,718 3,399 5,789 8,189 4,160 31,532 24,747 1,579

1987 Panel

1987: 1st quarter....... 88,131 11,291 40,543 15,793 3,717 3,075 6,230 7,707 3,883 32,216 24,529 2,616

2nd quarter ...... 88,237 10,691 39,345 14,857 3,597 3,222 6,142 7,795 3,979 31,470 24,702 1,869

3rd quarter ...... 88,601 10,648 38,681 13,605 3,485 3,208 5,881 7,759 3,861 31,670 25,198 1,624

4th quarter....... 89,067 10,558 40,395 15,748 3,425 3,194 5,833 7,818 3,941 32,073 25,150 2,179

1988: 1st quarter....... 89,719 10,630 40,853 15,921 3,607 3,172 5,916 7,919 4,053 32,282 25,410 1,996

2nd quarter ...... 89,963 10,212 39,418 14,527 3,534 3,159 5,824 7,986 4,006 31,615 25,403 1,448

3rd quarter ...... 90,401 10,354 38,201 13,285 3,382 3,150 5,706 7,909 4,001 31,279 24,947 1,296

4th quarter....... 90,481 10,461 40,102 15,314 3,329 3,186 5,813 7,876 4,012 31,952 25,228 1,495

1988 Panel

1988: 1st quarter....... 89,858 11,547 41,438 16,741 3,318 3,496 5,996 7,882 4,488 32,334 25,399 2,164

2nd quarter ...... 90,066 11,020 40,078 15,160 3,356 3,747 5,948 8,265 4,557 32,012 25,456 1,655

3rd quarter ...... 90,488 11,154 39,634 14,320 3,375 3,793 5,851 8,530 4,515 32,262 25,641 1,593

4th quarter....... 90,517 10,855 41,316 16,860 3,417 3,790 6,038 8,556 4,563 32,297 25,573 1,540

1989: 1st quarter....... 91,144 10,677 41,775 16,829 3,477 3,682 6,133 8,405 4,746 32,796 25,762 2,087

2nd quarter ...... 91,614 10,548 40,740 15,272 3,362 3,624 5,892 8,274 4,716 32,753 25,959 1,565

3rd quarter ...... 91,841 10,858 39,866 14,142 3,275 3,645 5,856 8,455 4,556 32,549 25,975 1,380

4th quarter....... 92,103 11,144 42,048 16,380 3,265 3,721 6,108 8,730 4,252 32,579 26,369 1,382

1989 Panel

1989: 1st quarter....... 91,394 10,949 41,101 16,408 3,744 3,388 5,787 8,104 4,575 32,470 25,621 1,907

2nd quarter ...... 91,819 10,256 40,160 15,078 3,604 3,522 5,725 8,190 4,563 32,510 25,890 1,631

3rd quarter ...... 92,083 10,538 39,496 13,878 3,597 3,620 5,640 8,299 4,441 32,505 26,154 1,473

See footnote at end of table.

D-5
Table D-2. Average Monthly Nonfarm Poverty and Household Participation in Means-Tested and

Nonmeans-Tested Government Programs—SIPP Panels: First Quarter 1984

to Fourth Quarter 1993—Continued

[In thousands]

Panel, year, and quarter

All

households

Nonfarm

poor

households

Received

Government

benefits

Received

meanstested

benefits

Received

AFDC

or other

nonSSI

public

assistance

Received

SSI

Received

food

stamps

Covered by

Medicaid

Lived in

public

or subsidized

housing

Received

nonmeanstested

benefits

Received

Social

Security or

RR

Received

unemployment

compensation

1990 Panel

1990: 1st quarter....... 91,776 10,864 42,687 16,690 3,523 3,239 5,939 8,348 4,576 33,472 26,257 2,407

2nd quarter ...... 92,308 10,462 41,827 15,303 3,696 3,315 6,184 8,607 4,470 33,397 26,412 2,011

3rd quarter ...... 92,722 11,055 41,419 14,397 3,711 3,354 6,254 8,871 4,452 33,686 26,745 1,921

4th quarter....... 92,421 11,381 43,554 17,130 3,722 3,369 6,334 9,014 4,431 33,939 26,529 2,288

1991: 1st quarter....... 93,058 11,548 44,708 17,776 3,879 3,482 6,631 9,326 4,502 34,922 26,702 3,354

2nd quarter ...... 93,278 11,367 43,316 16,230 4,004 3,418 6,664 9,462 4,490 34,434 26,732 2,818

3rd quarter ...... 93,443 11,555 42,568 15,212 4,150 3,475 6,750 9,853 4,513 34,364 26,705 2,681

4th quarter....... 93,289 11,545 44,975 17,921 4,045 3,516 6,857 10,015 4,452 34,944 26,642 3,183

1992: 1st quarter....... 93,879 11,679 46,292 18,448 4,089 3,744 7,152 10,339 4,504 36,286 26,943 4,244

1991 Panel

1991: 1st quarter....... 93,313 12,453 44,115 18,203 4,051 3,593 6,814 9,652 4,836 34,047 26,189 3,120

2nd quarter ...... 93,545 11,876 43,439 17,131 4,152 3,799 6,945 9,996 4,845 34,103 26,299 2,861

3rd quarter ...... 93,774 12,162 42,903 16,149 4,003 3,936 6,975 10,313 4,830 34,214 26,369 2,714

4th quarter....... 93,649 12,294 45,301 18,677 3,927 3,902 7,055 10,281 4,706 34,846 26,456 3,236

1992: 1st quarter....... 94,157 12,422 46,455 18,962 4,057 3,957 7,358 10,533 4,871 36,180 26,685 4,502

2nd quarter ...... 94,588 12,240 44,958 17,557 4,062 4,173 7,248 10,678 4,772 35,509 26,591 4,076

3rd quarter ...... 94,095 12,291 43,665 16,556 3,987 4,152 7,199 10,813 4,621 34,902 26,533 3,550

4th quarter....... 94,546 12,339 45,629 19,175 4,099 4,128 7,251 10,981 4,558 34,864 26,339 3,378

1992 Panel

1991: 4th quarter ...... 92,932 11,917 44,691 18,746 3,958 3,597 7,060 9,818 4,294 33,884 26,099 3,164

1992: 1st quarter....... 93,473 11,939 45,925 19,063 4,171 3,723 7,573 10,224 4,446 35,291 26,195 4,630

2nd quarter ...... 94,432 11,876 45,012 18,030 4,298 3,961 7,693 10,865 4,560 35,231 26,265 4,289

3rd quarter ...... 94,260 11,964 43,952 16,721 4,117 3,978 7,634 11,048 4,493 35,001 26,362 3,696

4th quarter....... 94,410 12,266 46,047 19,499 4,137 4,124 7,634 11,232 4,397 35,089 26,481 3,535

1993: 1st quarter....... 94,805 12,713 46,661 19,790 4,339 4,083 7,895 11,387 4,409 35,760 26,583 4,075

2nd quarter ...... 94,905 12,553 45,093 18,370 4,442 4,154 7,876 11,639 4,426 35,056 26,623 3,416

3rd quarter ...... 95,796 12,296 44,776 17,422 4,372 4,322 7,808 11,939 4,364 35,332 26,619 3,396

4th quarter....... 96,109 12,288 46,689 19,920 4,250 4,276 7,592 11,787 4,466 35,260 26,636 3,158

1993 Panel

1992: 4th quarter ...... 94,633 12,594 46,234 19,858 4,512 3,625 7,848 11,219 4,827 34,495 26,232 3,166

1993: 1st quarter....... 94,924 13,011 47,265 20,215 4,831 3,861 8,594 11,636 5,137 35,299 26,657 3,712

2nd quarter ...... 94,981 13,009 46,261 18,833 4,904 4,113 8,645 11,839 5,098 35,220 26,826 3,461

3rd quarter ...... 95,982 13,213 45,540 17,737 4,870 4,198 8,727 12,127 5,025 35,334 27,027 3,178

4th quarter....... 96,327 12,954 47,670 20,357 4,865 4,254 8,623 12,123 5,075 35,494 27,042 3,228

NA Not available.

D-6
Table D-3. Comparison of CPS and SIPP Poverty Rates, by Selected Characteristics: 1990 and 1991

[Estimates from SIPP based on 1990 panel file]

Characteristic

Percent below the poverty level Percentage

point

difference

CPS CPS-SIPP CPS/SIPP 1 SIPP

1990

Age

Total .............................................. 13.5 10.1 3.4 1.34

Under 18 years......................................... 20.6 16.8 3.8 1.23

18 to 64 years ......................................... 10.7 7.7 3.0 1.39

65 years and over ...................................... 12.2 8.1 4.1 1.51

Sex

Male .................................................. 11.7 8.2 3.5 1.43

Female ................................................ 15.2 11.9 3.3 1.28

Race and Hispanic Origin

White ................................................. 10.7 7.5 3.2 1.43

Black.................................................. 31.9 27.0 4.9 1.18

Hispanic origin2 ........................................ 28.1 21.2 6.9 1.33

1991

Age

Total .............................................. 14.2 10.6 3.6 1.34

Under 18 years......................................... 21.8 17.2 4.6 1.27

18 to 64 years ......................................... 11.4 8.3 3.1 1.37

65 years and over ...................................... 12.4 8.5 3.9 1.46

Sex

Male .................................................. 12.3 8.9 3.4 1.38

Female ................................................ 16.0 12.2 3.8 1.31

Race and Hispanic Origin

White ................................................. 11.3 8.1 3.2 1.40

Black.................................................. 32.7 27.1 5.6 1.21

Hispanic origin2 ........................................ 28.7 24.7 4.0 1.16

1

Standard errors for the 1990 and 1991 Current Population Survey poverty rates can be derived from appendices B of Current Population

Reports, Series P-60; Number 175 (181), ′′Poverty in the United States: 1990 (1991).′′ 2

Persons of Hispanic origin may be of any race.

D-7
Table D-4. Comparison of 1990 to 1991 Year-to-Year Percentage Point Changes in Poverty Rates Between

CPS and SIPP

Characteristic CPS SIPP

Age

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.7 0.5

Under 18 years. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 0.4

18 to 64 years. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.7 0.6

65 years and over . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 0.4

Sex

Male . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 0.7

Female . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.8 0.3

Race and Hispanic Origin

White . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 0.6

Black. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.8 0.1

Hispanic origin1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 3.5

1

Persons of Hispanic origin may be of any race.

D-8
Appendix E. Supplementary Tables: 1987 and 1988

Table E-1. Average Monthly Poverty, by Selected Characteristics: 1987 and 1988

[Numbers in thousands]

Characteristic

1987 1988

Total

Poor

Total

Poor

Number Percent Number Percent

All persons .............................. 239,784 31,980 13.3 242,187 30,524 12.6

Race and Hispanic Origin

White ..................................... 202,888 21,327 10.5 204,970 20,478 10.0

Not of Hispanic origin1 .................... 186,249 16,806 9.0 187,798 16,119 8.6

Black ..................................... 29,009 9,226 31.8 29,263 8,818 30.1

Hispanic origin ............................. 19,025 5,066 26.6 19,629 4,910 25.0

Not of Hispanic origin ....................... 220,759 26,914 12.2 222,559 25,614 11.5

Age

Under 18 years ............................ 63,505 12,954 20.4 63,711 12,493 19.6

18 to 64 years ............................. 148,099 16,239 11.0 149,906 15,293 10.2

65 years and over .......................... 28,181 2,787 9.9 28,571 2,738 9.6

Sex

Male ...................................... 116,569 14,076 12.1 117,840 13,429 11.4

Female.................................... 123,215 17,904 14.5 124,347 17,095 13.7

Educational Attainment (persons 18 years

and over)

Less than 4 years of high school ............. 42,884 9,223 21.5 42,771 8,697 20.3

High school graduate, no college............. 67,043 6,207 9.3 67,358 5,858 8.7

1 or more years of college................... 66,353 3,595 5.4 68,348 3,476 5.1

Disability Status (persons 15 to 69 years)

With a work disability ....................... 27,096 5,268 19.4 26,262 4,704 17.9

With no work disability ...................... 142,007 13,631 9.6 144,200 13,115 9.1

Residence

Metropolitan ............................... 184,173 22,088 12.0 185,663 21,071 11.3

Central city .............................. 76,125 13,829 18.2 78,991 12,981 16.4

Non-central city .......................... 108,048 8,259 7.6 106,672 8,090 7.6

Nonmetropolitan............................ 55,611 9,892 17.8 56,524 9,453 16.7

Region

Northeast.................................. 48,261 5,568 11.5 48,215 5,482 11.4

Midwest ................................... 60,010 7,252 12.1 61,407 6,943 11.3

South ..................................... 81,186 12,579 15.5 81,314 12,056 14.8

West...................................... 50,327 6,580 13.1 51,252 6,043 11.8

See footnotes at end of table.

E-1
Table E-1. Average Monthly Poverty, by Selected Characteristics: 1987 and 1988—Continued

[Numbers in thousands]

Characteristic

1987 1988

Total

Poor

Total

Poor

Number Percent Number Percent

Family Status

In families ................................. 207,433 25,350 12.2 209,208 24,004 11.5

In families with related children under

18 years ............................... 135,105 21,940 16.2 135,546 20,999 15.5

In married-couple families ................. 167,944 13,211 7.9 169,147 11,708 6.9

In married-couple families with related

children under 18 years ................ 107,111 10,803 10.1 107,502 9,654 9.0

In families with a female householder,

no spouse present ...................... 32,805 11,495 35.0 33,562 11,607 34.6

In families with a female householder,

no spouse present, with related

children under 18 years ................ 24,624 10,670 43.3 24,731 10,829 43.8

Unrelated individuals........................ 32,352 6,630 20.5 32,979 6,520 19.8

In non-family households .................. 30,209 5,821 19.3 31,000 5,825 18.8

Employment and Labor Force Status

(persons 18 years and over)

Employed full-time.......................... 92,066 3,390 3.7 94,612 3,189 3.4

Employed part-time......................... 20,196 2,228 11.0 20,687 2,284 11.0

Unemployed ............................... 5,750 2,538 44.1 4,850 2,008 41.4

Not in labor force........................... 58,267 10,870 18.7 58,327 10,550 18.1

Marital Status (persons 18 years

and over)

Married ................................... 105,957 7,171 6.8 106,404 6,317 5.9

Separated, divorced, or widowed............. 32,376 6,508 20.1 32,779 6,287 19.2

Never married ............................. 37,947 5,347 14.1 39,294 5,427 13.8

Family Size

1 person (unrelated individual) ............... 32,350 6,629 20.5 32,979 6,520 19.8

2 persons ................................. 53,399 4,796 9.0 52,980 4,367 8.2

3 persons ................................. 47,005 5,205 11.1 48,712 4,866 10.0

4 persons ................................. 56,808 5,783 10.2 56,379 5,401 9.6

5 persons ................................. 30,142 4,087 13.6 30,186 3,755 12.4

6 or more persons.......................... 20,080 5,480 27.3 20,950 5,614 26.8

Access to Health Insurance

Covered by health insurance ................ 207,409 21,256 10.2 211,496 20,594 9.7

Private insurance......................... 182,892 8,468 4.6 188,116 8,168 4.3

Medicare ................................ 30,207 3,198 10.6 30,711 3,201 10.4

Medicaid ................................ 17,474 12,071 69.1 17,502 11,875 67.8

Not covered by health insurance ............. 32,375 10,724 33.1 30,691 9,930 32.4

Receipt of Public Assistance

Received public assistance2 ................. 27,412 17,354 63.3 27,027 16,979 62.8

Did not receive public assistance............. 212,372 14,625 6.9 215,161 13,545 6.3

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

E-2
Table E-2. Persons Poor 2 or More Months, by Selected Characteristics: 1987 and 1988

[Numbers in thousands]

Characteristic

1987 panel 1987 1988

Total

Persons ever poor

over the panel

Total

Persons ever poor

during the year

Total

Persons ever poor

during the year

Number Percent Number Percent Number Percent

All persons ....................... 230,989 56,868 24.6 234,841 44,811 19.1 237,817 42,936 18.1

Race and Hispanic Origin

White .............................. 195,633 41,079 21.0 198,719 31,298 15.8 200,936 29,553 14.7

Not of Hispanic origin1 ............. 180,177 34,425 19.1 182,985 25,543 14.0 184,260 23,860 12.9

Black .............................. 27,807 13,361 48.0 28,413 11,479 40.4 28,952 11,485 39.7

Hispanic origin ...................... 17,443 7,434 42.6 17,871 6,442 36.0 18,842 6,354 33.7

Not of Hispanic origin ................ 213,546 49,434 23.1 216,970 38,370 17.7 218,975 36,582 16.7

Age

Under 18 years ..................... 63,349 21,518 34.0 63,097 17,427 27.6 63,318 16,755 26.5

18 to 64 years ...................... 142,966 31,308 21.9 145,063 23,952 16.5 147,192 22,646 15.4

65 years and over ................... 24,675 4,041 16.4 26,682 3,432 12.9 27,307 3,536 12.9

Sex

Male ............................... 111,506 25,721 23.1 113,523 19,992 17.6 115,536 19,164 16.6

Female............................. 119,484 31,147 26.1 121,318 24,820 20.5 122,281 23,772 19.4

Educational Attainment

(persons 18 years and over)

Less than 4 years of high school ...... 38,834 13,582 35.0 40,936 11,938 29.2 41,047 11,067 27.0

High school graduate, no college...... 64,861 13,115 20.2 66,243 9,580 14.5 66,083 9,101 13.8

1 or more years of college............ 63,945 8,653 13.5 64,566 5,866 9.1 67,369 6,014 8.9

Disability Status (persons 15 to

69 years)

With a work disability ................ 24,149 7,915 32.8 25,419 7,047 27.7 24,501 6,253 25.5

With no work disability ............... 139,091 28,201 20.3 140,522 20,775 14.8 143,480 20,101 14.0

Residence

Metropolitan ........................ 175,188 39,078 22.3 179,100 30,409 17.0 181,276 29,938 16.5

Central city ....................... 68,772 20,360 29.6 71,459 17,385 24.3 75,238 17,316 23.0

Non-central city ................... 106,416 18,718 17.6 107,640 13,024 12.1 106,039 12,622 11.9

Nonmetropolitan..................... 55,801 17,790 31.9 55,742 14,402 25.8 56,540 12,998 23.0

Region

Northeast........................... 45,181 9,248 20.5 46,833 7,562 16.1 46,501 7,424 16.0

Midwest ............................ 60,717 13,464 22.2 60,365 10,498 17.4 61,444 9,913 16.1

South .............................. 77,407 22,061 28.5 79,147 17,402 22.0 80,010 16,860 21.1

West............................... 47,684 12,095 25.4 48,497 9,349 19.3 49,862 8,740 17.5

Family Status

In families .......................... 202,704 47,703 23.5 205,281 36,831 17.9 206,852 35,006 16.9

In families with related children

under 18 years................... 135,081 39,377 29.2 135,189 30,877 22.8 135,619 29,692 21.9

In married-couple families .......... 166,004 30,241 18.2 167,281 21,666 13.0 168,633 20,089 11.9

In married-couple families with

related children under 18 years . . 108,689 24,002 22.1 107,988 17,226 16.0 108,639 16,379 15.1

In families with a female householder, no spouse present....... 31,224 15,934 51.0 32,303 14,014 43.4 32,555 13,986 43.0

In families with a female

householder, no spouse

present, with related children

under 18 years ................ 23,635 14,270 60.4 24,396 12,789 52.4 24,036 12,559 52.3

Unrelated individuals................. 28,285 9,164 32.4 29,560 7,980 27.0 30,965 7,930 25.6

In non-family households ........... 26,760 8,445 31.6 27,851 7,278 26.1 29,249 7,242 24.8

See footnotes at end of table.

E-3
Table E-2. Persons Poor 2 or More Months, by Selected Characteristics: 1987 and 1988—Continued

[Numbers in thousands]

Characteristic

1987 panel 1987 1988

Total

Persons ever poor

over the panel

Total

Persons ever poor

during the year

Total

Persons ever poor

during the year

Number Percent Number Percent Number Percent

Employment and Labor Force

Status (persons 18 years and over)

Employed full-time................... 88,470 11,926 13.5 88,671 7,488 8.4 91,937 7,176 7.8

Employed part-time.................. 19,896 4,952 24.9 20,465 3,687 18.0 20,901 3,559 17.0

Unemployed ........................ 6,732 3,953 58.7 7,107 3,633 51.1 5,321 2,556 48.0

Not in labor force.................... 52,543 14,519 27.6 55,501 12,577 22.7 56,340 12,890 22.9

Marital Status (persons 18 years

and over)

Married ............................ 104,695 16,664 15.9 105,935 12,003 11.3 106,054 10,674 10.1

Separated, divorced, or widowed...... 28,890 9,819 34.0 30,441 8,523 28.0 30,933 8,004 25.9

Never married ...................... 34,056 8,866 26.0 35,369 6,858 19.4 37,511 7,504 20.0

Family Size

1 person (unrelated individual) ........ 28,285 9,164 32.4 29,560 7,980 27.0 30,965 7,930 25.6

2 persons .......................... 51,329 9,209 17.9 52,640 7,100 13.5 52,324 6,686 12.8

3 persons .......................... 46,445 10,551 22.7 46,967 8,193 17.4 48,443 7,086 14.6

4 persons .......................... 55,646 11,284 20.3 56,199 8,140 14.5 55,850 7,911 14.2

5 persons .......................... 29,320 7,620 26.0 29,602 6,063 20.5 30,407 6,068 20.0

6 or more persons................... 19,964 9,038 45.3 19,873 7,335 36.9 19,827 7,254 36.6

Access to Health Insurance

Covered by health insurance ......... 201,175 40,154 20.0 204,064 30,977 15.2 208,391 29,110 14.0

Private insurance.................. 177,841 25,147 14.1 179,801 16,424 9.1 185,503 15,515 8.4

Medicare ......................... 26,269 4,478 17.0 28,298 3,855 13.6 29,313 4,015 13.7

Medicaid ......................... 16,644 13,597 81.7 17,297 13,469 77.9 17,126 13,003 75.9

Not covered by health insurance ...... 29,814 16,714 56.1 30,778 13,834 44.9 29,426 13,826 47.0

Receipt of Public Assistance

Received public assistance2 .......... 27,140 21,130 77.9 27,803 20,365 73.2 26,565 19,333 72.8

Did not receive public assistance...... 203,850 35,738 17.5 207,038 24,446 11.8 211,252 23,603 11.2

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

E-4
Table E-3. Persons Poor Each Month of 1987 and 1988, by Selected Characteristics

[Numbers in thousands]

Characteristic

Total

Persons poor entire 24 months

Number Percent

All persons.................................................... 231,363 10,162 4.4

Race and Hispanic Origin

White........................................................... 195,936 5,544 2.8

Not of Hispanic origin1

.......................................... 180,480 3,848 2.1

Black ........................................................... 27,862 4,175 15.0

Hispanic origin .................................................. 17,443 1,854 10.6

Not of Hispanic origin ............................................ 213,920 8,308 3.9

Age

Under 18 years .................................................. 62,899 4,799 7.6

18 to 64 years................................................... 143,377 3,989 2.8

65 years and over ............................................... 25,086 1,374 5.5

Sex

Male ........................................................... 111,742 4,076 3.6

Female ......................................................... 119,621 6,087 5.1

Educational Attainment (persons 18 years and over)

Less than 4 years of high school .................................. 39,309 3,504 8.9

High school graduate, no college .................................. 65,101 1,399 2.1

1 or more years of college ........................................ 64,055 460 0.7

Disability Status (persons 15 to 69 years)

With a work disability............................................. 24,294 1,768 7.3

With no work disability............................................ 139,510 3,159 2.3

Residence

Metropolitan..................................................... 175,508 6,936 4.0

Central city.................................................... 68,923 4,767 6.9

Non-central city................................................ 106,585 2,169 2.0

Nonmetropolitan ................................................. 55,855 3,226 5.8

Region

Northeast ....................................................... 45,242 1,792 4.0

Midwest ........................................................ 60,793 2,205 3.6

South .......................................................... 77,573 4,668 6.0

West ........................................................... 47,756 1,496 3.1

Family Status

In families....................................................... 202,930 7,975 3.9

In families with related children under 18 years.................... 134,746 7,403 5.5

In married-couple families....................................... 166,214 2,976 1.8

In married-couple families with related children under 18 years.... 108,360 2,472 2.3

In families with a female householder, no spouse present .......... 31,240 4,872 15.6

In families with a female householder, no spouse present,

with related children under 18 years .......................... 23,629 4,837 20.5

Unrelated individuals ............................................. 28,433 2,187 7.7

In non-family households ....................................... 26,908 1,985 7.4

Employment and Labor Force Status (persons 18 years and over)

Employed full-time ............................................... 88,175 302 0.3

Employed part-time .............................................. 20,231 380 1.9

Unemployed .................................................... 6,944 666 9.6

Not in labor force ................................................ 53,114 4,015 7.6

See footnotes at end of table.

E-5
Table E-3. Persons Poor Each Month of 1987 and 1988, by Selected Characteristics—Continued

[Numbers in thousands]

Characteristic

Total

Persons poor entire 24 months

Number Percent

Marital Status (person 18 years and over)

Married ......................................................... 104,910 1,598 1.5

Separated, divorced, or widowed .................................. 28,982 2,311 8.0

Never married ................................................... 34,571 1,455 4.2

Family Size

1 person (unrelated individual) .................................... 28,433 2,187 7.7

2 persons ....................................................... 51,464 1,414 2.7

3 persons ....................................................... 46,495 1,423 3.1

4 persons ....................................................... 55,666 1,152 2.1

5 persons ....................................................... 29,331 1,354 4.6

6 or more persons ............................................... 19,974 2,631 13.2

Access to Health Insurance

Covered by health insurance ...................................... 201,737 8,083 4.0

Private insurance .............................................. 178,355 1,319 0.7

Medicare ..................................................... 26,514 1,524 5.7

Medicaid...................................................... 16,739 6,382 38.1

Not covered by health insurance................................... 29,626 2,079 7.0

Receipt of Public Assistance

Received public assistance2

....................................... 27,344 8,225 30.1

Did not receive public assistance .................................. 204,019 1,938 0.9

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

E-6
Table E-4. Spells of Poverty for Persons Who Became Poor During the 1987 SIPP Panel, by

Selected Characteristics

[Numbers in thousands]

Characteristic

Total

spells

Percentage

of spells

rightcensored

Survival rates of poverty spells afterMedian

spell

duration

1

month

4

months

8

months

12

months

16

months

20

months

24

months

All persons ....................... 51,071 27.8 1.0000 0.4969 0.2980 0.2080 0.1658 0.1368 0.0920 4.0

Race and Hispanic Origin

White .............................. 38,836 26.4 1.0000 0.4844 0.2798 0.1913 0.1454 0.1112 (B) 3.9

Not of Hispanic origin1 ............. 33,747 26.0 1.0000 0.4692 0.2711 0.1806 0.1382 0.1097 (B) 3.8

Black .............................. 10,209 33.4 1.0000 0.5522 0.3774 0.2706 0.2413 0.2352 (B) 5.3

Hispanic origin ...................... 5,831 29.4 1.0000 0.5527 0.3370 0.2696 0.2104 (B) (X) 5.4

Not of Hispanic origin ................ 45,239 27.6 1.0000 0.4897 0.2929 0.1995 0.1599 0.1358 0.0923 3.9

Age

Under 18 years ..................... 16,728 29.7 1.0000 0.5279 0.3304 0.2388 0.1907 0.1482 (B) 4.6

18 to 64 years ...................... 31,336 25.6 1.0000 0.4725 0.2688 0.1802 0.1408 0.1155 (B) 3.9

65 years and over ................... 3,007 39.6 1.0000 0.5780 0.4155 0.3209 0.2854 0.2854 (B) 6.6

Sex

Male ............................... 24,222 26.1 1.0000 0.4672 0.2708 0.1912 0.1559 0.1264 (B) 3.8

Female............................. 26,848 29.3 1.0000 0.5236 0.3223 0.2230 0.1746 0.1460 (B) 4.5

Educational Attainment (persons 18

years and over)

Less than 4 years of high school ...... 10,919 32.3 1.0000 0.5533 0.3747 0.2817 0.2380 0.2023 (B) 5.4

High school graduate, no college...... 13,558 26.1 1.0000 0.4683 0.2657 0.1629 0.1117 0.0984 (B) 3.8

1 or more years of college............ 9,865 21.9 1.0000 0.4206 0.1988 0.1311 0.1104 (B) (B) 3.6

Disability Status (persons 15 to

69 years)

With a work disability ................ 6,464 31.7 1.0000 0.5354 0.3488 0.2498 0.2221 0.1853 (B) 5.0

With no work disability ............... 28,598 25.1 1.0000 0.4652 0.2564 0.1728 0.1315 0.1112 (B) 3.8

Residence

Metropolitan ........................ 35,898 25.9 1.0000 0.4803 0.2770 0.1871 0.1490 0.1257 (B) 3.9

Central city ....................... 18,048 27.2 1.0000 0.4745 0.2797 0.2058 0.1757 0.1563 (B) 3.9

Non-central city ................... 17,851 24.6 1.0000 0.4864 0.2743 0.1678 0.1213 0.0933 (B) 3.9

Nonmetropolitan..................... 15,172 32.3 1.0000 0.5371 0.3492 0.2587 0.2067 0.1643 (B) 4.9

Region

Northeast........................... 8,051 28.7 1.0000 0.4826 0.3381 0.2324 0.1764 0.1534 (B) 3.9

Midwest ............................ 12,863 28.1 1.0000 0.4684 0.2960 0.2128 0.1667 0.1305 (B) 3.8

South .............................. 18,501 29.9 1.0000 0.5542 0.3205 0.2179 0.1839 0.1611 (B) 5.1

West............................... 11,656 23.4 1.0000 0.4471 0.2366 0.1697 0.1282 0.0910 (B) 3.7

Family Status

In families .......................... 42,215 27.2 1.0000 0.4920 0.2962 0.2040 0.1622 0.1313 (B) 4.0

In families with related children

under 18 years................... 34,157 27.8 1.0000 0.4998 0.3027 0.2116 0.1716 0.1376 (B) 4.0

In married-couple families .......... 29,125 23.1 1.0000 0.4347 0.2509 0.1654 0.1330 0.0987 (B) 3.7

In married-couple families with

related children under 18 years . . 23,265 23.2 1.0000 0.4354 0.2472 0.1627 0.1330 0.0969 (B) 3.7

In families with a female householder, no spouse present......... 11,370 38.3 1.0000 0.6504 0.4257 0.3163 0.2437 0.2246 (B) 6.6

In families with a female householder, no spouse present, with

related children under 18 years . . 9,594 39.6 1.0000 0.6627 0.4486 0.3401 0.2696 0.2456 (B) 6.9

Unrelated individuals ............... 8,856 30.5 1.0000 0.5204 0.3065 0.2275 0.1833 0.1622 (B) 4.3

In non-family households ........... 8,315 31.4 1.0000 0.5272 0.3104 0.2278 0.1931 0.1701 (B) 4.5

See footnotes at end of table.

E-7
Table E-4. Spells of Poverty for Persons Who Became Poor During the 1987 SIPP Panel, by

Selected Characteristics—Continued

[Numbers in thousands]

Characteristic

Total

spells

Percentage

of spells

rightcensored

Survival rates of poverty spells afterMedian

spell

duration

1

month

4

months

8

months

12

months

16

months

20

months

24

months

Employment and Labor Force

Status (persons 18 years and over)

Employed full-time................... 11,348 22.2 1.0000 0.4254 0.2195 0.1280 0.1004 (B) (B) 3.6

Employed part-time.................. 5,513 25.9 1.0000 0.4743 0.2736 0.1715 0.1149 (B) (B) 3.9

Unemployed ........................ 4,144 25.5 1.0000 0.5423 0.3139 0.2209 0.1496 0.1452 (B) 4.8

Not in labor force.................... 13,337 31.6 1.0000 0.5137 0.3267 0.2450 0.2155 0.1916 (B) 4.3

Marital Status (persons 18 years

and over)

Married ............................ 17,203 22.8 1.0000 0.4316 0.2416 0.1570 0.1269 0.0967 (B) 3.7

Separated, divorced, or widowed...... 8,251 33.1 1.0000 0.5798 0.3711 0.2635 0.2009 0.1839 (B) 5.3

Never married ...................... 8,889 28.8 1.0000 0.4872 0.2770 0.1965 0.1613 0.1497 (B) 3.9

Family Size

1 person (unrelated individual) ........ 8,856 30.5 1.0000 0.5204 0.3065 0.2275 0.1833 0.1622 (B) 4.3

2 persons .......................... 8,539 29.1 1.0000 0.5454 0.3350 0.2206 0.1680 0.1445 (B) 5.1

3 persons .......................... 8,430 25.5 1.0000 0.5210 0.3229 0.1767 0.1373 0.1303 (X) 4.4

4 persons .......................... 11,024 25.8 1.0000 0.4296 0.2367 0.1684 0.1435 (B) (X) 3.6

5 persons .......................... 7,379 26.3 1.0000 0.4549 0.2566 0.1976 0.1858 0.1258 (B) 3.8

6 or more persons................... 6,842 30.3 1.0000 0.5281 0.3509 0.2863 0.1901 (B) (X) 5.3

Access to Health Insurance

Covered by health insurance 30,968 27.9 1.0000 0.4722 0.2949 0.2189 0.1757 0.1527 (B) 3.9

Private insurance.................. 23,993 22.6 1.0000 0.4016 0.2147 0.1402 0.1140 0.1021 (B) 3.5

Medicare ......................... 3,449 38.0 1.0000 0.5743 0.3993 0.3077 0.2715 0.2606 (B) 6.1

Medicaid ......................... 6,247 50.7 1.0000 0.7499 0.5978 0.5246 0.4214 0.3458 (B) 13.5

Not covered by health insurance ...... 20,103 27.5 1.0000 0.5355 0.3027 0.1910 0.1507 0.1141 (B) 4.5

Receipt of Public Assistance

Received public assistance2 .......... 11,406 43.1 1.0000 0.6923 0.5273 0.4363 0.3613 0.3038 (B) 9.0

Did not receive public assistance...... 39,664 23.4 1.0000 0.4397 0.2273 0.1365 0.1044 0.0850 (B) 3.7

B Base less than 200,000. X Not applicable.

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

E-8
Table E-5. Transitions Into and Out of Poverty, by Selected Characteristics: 1987 to 1988

[Numbers in thousands]

Poverty status in 1987

Total

Poverty status in 1988

Poor Nonpoor

All persons

Total ......................................................... 230,989 23,144 207,846

Poor ......................................................... 24,922 18,520 6,402

Nonpoor ...................................................... 206,068 4,624 201,444

Race and Hispanic Origin

White

Total ......................................................... 195,633 14,194 181,439

Poor ......................................................... 15,363 10,747 4,616

Nonpoor ...................................................... 180,270 3,447 176,823

Black

Total ......................................................... 27,807 8,009 19,798

Poor ......................................................... 8,402 6,973 1,429

Nonpoor ...................................................... 19,405 1,036 18,369

Hispanic origin1

Total ......................................................... 17,443 3,812 13,632

Poor ......................................................... 3,982 3,260 722

Nonpoor ...................................................... 13,461 551 12,910

Age

Under 18

Total ......................................................... 59,571 9,763 49,808

Poor ......................................................... 10,544 8,133 2,411

Nonpoor ...................................................... 49,028 1,630 47,398

18 to 64

Total ......................................................... 144,791 11,073 133,717

Poor ......................................................... 12,007 8,398 3,608

Nonpoor ...................................................... 132,784 2,675 130,109

65 and over

Total ......................................................... 26,627 2,307 24,320

Poor ......................................................... 2,371 1,988 383

Nonpoor ...................................................... 24,256 319 23,937

Sex

Male

Total ......................................................... 111,506 9,779 101,726

Poor ......................................................... 10,645 7,791 2,855

Nonpoor ...................................................... 100,860 1,989 98,872

Female

Total ......................................................... 119,484 13,364 106,119

Poor ......................................................... 14,276 10,729 3,547

Nonpoor ...................................................... 105,207 2,635 102,572

Educational Attainment (persons 18 years and over)

Less than 4 years of high school

Total ......................................................... 39,542 7,332 32,210

Poor ......................................................... 7,740 6,262 1,477

Nonpoor ...................................................... 31,803 1,070 30,733

High school graduate, no college

Total ......................................................... 58,008 3,762 54,246

Poor ......................................................... 3,914 2,609 1,305

Nonpoor ...................................................... 54,095 1,153 52,942

1 or more years of college

Total ......................................................... 73,868 2,287 71,581

Poor ......................................................... 2,725 1,515 1,210

Nonpoor ...................................................... 71,143 771 70,372

See footnotes at end of table.

E-9
Table E-5. Transitions Into and Out of Poverty, by Selected Characteristics: 1987 to 1988—Continued

[Numbers in thousands]

Poverty status in 1987

Total

Poverty status in 1988

Poor Nonpoor

Region

Northeast

Total ......................................................... 45,181 4,051 41,130

Poor ......................................................... 3,825 3,134 690

Nonpoor ...................................................... 41,356 917 40,439

Midwest

Total ......................................................... 60,717 5,160 55,557

Poor ......................................................... 5,765 4,004 1,761

Nonpoor ...................................................... 54,953 1,156 53,796

South

Total ......................................................... 77,407 9,828 67,579

Poor ......................................................... 10,562 8,177 2,384

Nonpoor ...................................................... 66,845 1,650 65,195

West

Total ......................................................... 47,684 4,105 43,580

Poor ......................................................... 4,770 3,204 1,566

Nonpoor ...................................................... 42,914 901 42,013

Family Status

In married-couple families both years

Total ......................................................... 161,148 8,605 152,543

Poor ......................................................... 9,586 6,613 2,973

Nonpoor ...................................................... 151,562 1,992 149,570

In other family types both years

Total ......................................................... 32,377 8,985 23,392

Poor ......................................................... 9,391 7,642 1,749

Nonpoor ...................................................... 22,986 1,343 21,643

Unrelated individual both years

Total ......................................................... 25,738 4,148 21,590

Poor ......................................................... 4,392 3,496 896

Nonpoor ...................................................... 21,346 652 20,694

Work Experience (persons 18 years and over)

Worked year-round, full-time both years

Total ......................................................... 66,178 753 65,425

Poor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 881 459 422

Nonpoor ...................................................... 65,298 294 65,004

Worked, not year-round, full-time both years

Total ......................................................... 32,940 3,122 29,818

Poor ......................................................... 3,208 2,028 1,179

Nonpoor ...................................................... 29,733 1,093 28,639

Did not work either year

Total ......................................................... 42,409 6,967 35,443

Poor ......................................................... 7,227 6,096 1,131

Nonpoor ...................................................... 35,182 870 34,311

Receipt of Public Assistance

Received public assistance both years2

Total ......................................................... 24,897 15,513 9,383

Poor ......................................................... 16,387 14,040 2,347

Nonpoor ...................................................... 8,509 1,473 7,037

Did not receive public assistance either year

Total ......................................................... 194,934 5,620 189,314

Poor ......................................................... 6,209 3,321 2,888

Nonpoor ...................................................... 188,725 2,299 186,426

1

Persons of Hispanic origin may be of any race.

2

Public assistance programs include AFDC, General Assistance, Supplemental Security Income, food stamps, Medicaid, and housing

assistance.

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