1

CPS OVERLAP ANALYSIS TEAM TECHNICAL REPORT 1

COMPARISONS OF LABOR FORCE ESTIMATES FROM

THE PARALLEL SURVEY AND THE CPS DURING 1993:

MAJOR LABOR FORCE ESTIMATES

Prepared by

Anne E. Polivka

for the

Labor Force Analysis Work Group

Anne E. Polivka, Chair

Sharon R. Cohany

Harvey R. Hamel

Steven E. Haugen

Francis W. Horvath

Thomas J. Nardone

Edwin L. Robison

Paul M. Ryscavage

March 18, 1994
ACKNOWLEDGMENTS

We would like to acknowledge the assistance of Athar Malik in the processing of the data

for this report. We would also like to acknowledge the contributions of the members of

the CPS Questionnaire Design Subcommittee without whose guidance our work could not

have been accomplished. Members of the committee throughout the years included, John

E. Bregger, Shail Butani, Cathryn S. Dippo, Harvey R. Hamel. Anne E. Polivka, Norris C.

Tucker and Alan Tupek from the Bureau of Labor Statistics; Chester E. Bowie, Lawrence

S. Cahoon, Kathleen P. Creighton, Donna L. Kostanich, Elizabeth A. Martin, Michael

McMahon, Jennifer M. Rothgeb, Thomas S. Scopp and Ronald R. Tucker from the

Bureau of the Census.
2

TABLE OF CONTENTS

INTRODUCTION ...................................................................................................... 3

SURVEY DESIGN HIGHLIGHTS

 I. Sample Design .................................................................................................... 5

 II. Data Collection Design ....................................................................................... 5

 III. Estimation and Analysis ...................................................................................... 6

MAJOR LABOR FORCE ESTIMATES

 I. Highlights ............................................................................................................ 8

 II. Unemployment Rates ........................................................................................... 11

 A. Comparisons of the Total Unemployment Rates ............................................. 11

 B. Comparisons for Specific Demographic Groups ............................................. 14

 1. Unemployment Rates for Men and Women ................................................ 14

 2. Unemployment Rates for Race and Ethnic Groups ..................................... 18

 3. Unemployment Rates for Specific Age Groups .......................................... 20

 C. Discussion of Possible Causes of Differences in the

 Unemployment Rates....................................................................................... 24

 1. Components of Unemployment .................................................................. 24

 2. Questionnaire Changes and Automation Effects ........................................ 25

 III. Employment-to-Population Ratios ..................................................................... 29

 A. Comparisons of the Total Employment-to-Population Ratios ........................ 29

 B. Comparisons for Specific Demographic Groups ............................................ 30

 1. Employment-to-Population Ratios for Men and Women ............................ 30

 2. Employment-to-Population Ratios for Race and Ethnic Groups ................. 35

 3. Employment-to-Population Ratios for Specific Age Groups ....................... 36

 C. Discussion of Possible Causes of Differences in the

 Employment-to-Population Ratios ................................................................ 38

 1. Components of Employment ..................................................................... 38

 2. Questionnaire Changes and Automation Effects ...................................... 39

 3. Unemployment to Employment Transitions ............................................... 41

 IV. Labor Force Participation Rates ......................................................................... 44

 A. Comparisons of the Total Labor Force Participation Rates ............................ 44

 B. Comparisons for Specific Demographic Groups ............................................ 45

 1. Labor Force Participation Rates for Men and Women ............................... 46

 2. Labor Force Participation Rates for Specific Age Groups ......................... 49

APPENDICES ............................................................................................................. 50

REFERENCES ............................................................................................................ 58
3

INTRODUCTION

The Current Population Survey (CPS), a national survey of 60,000 households, provides a

monthly picture of the Nation's labor force including measurements of total employment,

unemployment, and characteristics of those not in the labor force. Conceived in the

1940's, the CPS has remained virtually unchanged since 1967. However, since then, there

have been many societal changes, including growth in service sector employment; an

increase in the role of women in the labor force, particularly mothers; and shifts in the

nature of employment, such as more part-time work and less permanent attachment of

employees to their employers. In addition, there have been many advances in survey

design techniques and data collection procedures which facilitate the development of more

accurate measures. To reflect these changes, in 1986, the Bureau of Labor Statistics

(BLS) and the Bureau of the Census began a collaborative effort to redesign the CPS.

The primary goal of the redesign was to improve the quality of the data derived from the

survey by modifying the questionnaire to elicit more accurate data from respondents and

converting all data collection to computer-assisted interviewing in order to reduce the

potential for interviewer error.

To assess the effects of the redesign, a parallel survey of 12,000 households was

conducted using the new collection procedures and questionnaire for the period July 1992

through December 1993. In this report, we compare labor force estimates obtained from

the Parallel Survey with estimates obtained from the CPS1. These comparisons provide

our best estimate of the effects of changing from the questionnaire and data collection

procedures used prior to January 1994 to those used from January 1994 forward.2

This document contains two sections. The first section highlights survey design features

relevant to interpreting the estimates presented in this report. The second summarizes

differences in the estimated unemployment rates, employment-to-population ratios, and

labor force participation rates from the two surveys (the major labor force estimates.)

Salient findings are highlighted at the start of each section that contains estimates. Brief

discussions of the reasons for differences between the surveys are provided in each

section. More detailed discussions of the effects of questionnaire changes and computerassisted interviewing can be found in the reports of the Questionnaire Evaluation Work

 

1 The estimates presented for the CPS may not agree precisely with published estimates due to differences

in weighting, compositing, and other estimation procedures.

2 The effect of other design differences such as switching to 1990 Census-based population controls, the

number of post stratification cells and the percentage of interviews conducted using centralized

interviewing are documented in Effects of Design Differences Between the Parallel Survey and the

Redesigned Current Population Survey, CPS Bridge Team Technical Report 3, by Lawrence Cahoon and

Donna Kostanich.
4

Group and the Mode Effects Work Group3 The questions used in both surveys to classify

an individual's labor force status appear side-by-side in appendix A. The questions are

presented by series. A second technical report will discuss estimates of the characteristics

of the unemployed, employed, and those not in the labor force (e.g., the duration of

unemployment, the estimated percentage of the employed who are part time for economic

reasons, and the estimated percentage of those who are not in the labor force who are

discouraged workers.)

Throughout this report, the estimates generated from the data collected with the "old"

questionnaire and the State-based 60,000 household sample will be referred to as the CPS

estimates or the CPS. Estimates generated from the data collected with the "new" revised

questionnaire using the 12,000 household national parallel survey will be referred to as the

Parallel Survey estimates or the Parallel Survey.

This report is preliminary. More detailed discussion and analysis of the data will be

presented in a final version of this report. In addition, the final version will include an

examination of data related to the consistency of the estimates, such as gross flow and

month-in-sample estimates.

 

3 Revisions to the CPS Questionnaire: Effects on Data Quality, by Jennifer Rothgeb and Mode Effects

Analysis of Major Labor Force Estimates by Jenny Thompson.
5

SECTION 1

SURVEY DESIGN HIGHLIGHTS

I. Sample Design

The CPS includes 60,000 households monthly that are selected to represent the population

in the Nation and each State. The probability sample of housing units is drawn using a

multistage stratification procedure. The sampled households are located in 729 selected

geographic areas4. The largest metropolitan areas within each state are always included;

the remaining areas of a State are sampled on a probability basis, with the probability of

selection proportionate to the population of the area. The sample is designed to meet

specific reliability criteria for the Nation and each State. For the Nation as a whole, the

sample is designed to provide a 1.7-percent monthly coefficient of variation5 on the

estimated unemployment rate, assuming a 6-percent rate. This means that a change of 0.2

percentage point in the estimated unemployment rate is significant at a 90-percent

confidence level.

The sample design for the Parallel Survey is that used by the National Crime Victimization

Survey (NCVS), which is conducted by the Bureau of the Census for the Bureau of

Justice Statistics. The Parallel Survey sample is a stratified multistage sample with 12,000

housing units surveyed monthly; it has 283 geographic areas that are only selected to be

nationally representative. Thus, the Parallel Survey was not a State-based sample design,

and, therefore, the sample within a geographic State was not necessarily representative of

that State's population. This design was chosen because the major purpose of the Parallel

Survey was to measure effects at the national level. Cost constraints mitigated against

designing a parallel survey that would measure effects at the State level. The monthly

coefficient of variation for the estimated national unemployment rate from the Parallel

Survey is 3.5 percent, assuming a 6-percent rate.

II. Data Collection Design

In an effort to balance respondent burden with improved estimates of change, households

are interviewed for 4 consecutive months, not interviewed for the next 8 consecutive

months, and then interviewed for another 4 consecutive months. Each month, a new

household panel of approximately one-eighth the total monthly sample size (60,000/8 ≅

7,500 households for the CPS and 12,000/8 ≅ 1,500 for the Parallel Survey) is initiated,

and the panel which received its eighth interview the previous month is dropped. Given

 

4 Following each decennial census, a new sample of areas is selected with probability proportionate to

population size. The current sample is based on the 1980 decennial census.

5 The coefficient of variation of an estimate is defined as the standard error of the estimate divided by the

estimate.
6

this rotating panel structure, in any month one eighth of the households will be receiving

the first interview, one eighth will be receiving their second interview, one eighth will be

receiving their third interview, etc. This rotating panel structure also means that threequarters of the sample in a given month is retained in the sample the next month,

improving the estimates of month-to-month change. However, since the Parallel Survey

was initiated in 1992, and it takes 16 months to phase in this type of rotation scheme,

September 1993 was the first month in which the rotation scheme was completely in place.

In both the CPS and the Parallel Survey, first and fifth month-in-sample households are

interviewed through personal visits. For subsequent months, the majority of interviews

are conducted by telephone.

Most of the CPS data are collected with a paper survey instrument and translated into

computer readable form using FOSDIC6 technology. Approximately 9 percent of the data

are collected by interviewers working in two centralized facilities using computer-assisted

telephone interviewing.

All the data for the Parallel Survey were collected using computer-assisted interviewing.

Eighty percent of the data were collected by field representatives using laptop computers,

either during personal visits to respondents' homes or by telephone from their own homes.

The remaining 20 percent of the data were collected using computer-assisted telephone

interviewing by a separate staff of interviewers working in the same two centralized

facilities used for the CPS.

A Spanish version of the new, computerized questionnaire was also developed and loaded

onto the computers of all Spanish-speaking interviewers, both in the field and the

centralized telephone facilities. While interviews conducted from the centralized

telephone facilities with Spanish-speaking respondents were conducted in Spanish to the

extent possible, the extent of usage by field representatives is unknown. A Spanish

version of the old questionnaire does not exist, leaving each interviewer to formulate their

own translation. To the extent the lack of standardization in question wording results in

increased response variance, estimates for small subpopulations, such as Hispanics, will be

even more highly variable than one would expect, given their small sample sizes.

III. Estimation and Analysis

The primary basis of the comparisons presented in this report are annual average estimates

for 1993 (January to December). However, some quarterly and 3-month moving average

estimates are also presented. Although the Parallel Survey was fully operational in July

1992, only data from September 1992 to December 1993 are available for analytical use,

due to factors related to the initialization of the new procedures and implementation of the

revised questionnaire.

 

6 Film Optical Sensing Device for Input to Computers.
7

Estimates have been generated using edited data and final weights for both the CPS and

the Parallel Survey. The final weights used in this report are based on the 1980 Census

population controls. None of the estimates presented is composited or seasonally

adjusted.

All standard errors and test statistics for weighted data are based on generalized variance

functions. Throughout this report, asterisks are used to denote differences that are

statistically significant at a 10-percent level. For the most part, the null hypothesis being

tested is that there is no difference in the corresponding estimates from the CPS and

Parallel Survey. In many cases, the actual p-value for testing this hypothesis is displayed.

The p-value gives an indication of the probability of making an error if one were to reject

the null hypothesis, assuming it is true. A p-value of less than .10 indicates there is

sufficient evidence to reject the null hypothesis, that is, taking into account sampling error,

there is evidence that the estimates from the two surveys are different. However, failing

to reject the null hypothesis does not necessarily imply that the hypothesis is in fact true.
8

SECTION 2

MAJOR LABOR FORCE ESTIMATES

In this section, we compare the estimated unemployment rates, employment-to-population

ratios, and labor force participation rates from the Parallel Survey and CPS.

I. Highlights are:

Unemployment Rate

• The overall estimated annual unemployment rate as measured in the Parallel Survey

was 0.5 percentage point higher than the overall estimated annual unemployment

rate as measured by the CPS. This difference between surveys was significant at

the 1 percent level.

• The estimated unemployment rate was higher in the Parallel Survey than in the CPS

for every quarter of 1993. The differences were significant in three of the four

quarters.

• Although the estimated unemployment rate was higher in the Parallel Survey than in

the CPS, the general trend in the unemployment rate over calendar year 1993 was

the same for both surveys. The unemployment rate in the fourth quarter of 1993

was significantly lower than the unemployment rate in the first quarter of 1993 in

both surveys.

• The estimated annual unemployment rate was higher in the Parallel Survey than in

the CPS for almost every demographic group examined. However, only women

(adult women, white women, black women, other race women and Hispanic

women), teenagers, and those 65 and older had significantly higher rates.

• The difference between surveys in the annual unemployment rates was relatively

larger for women than for men. In other words, the percentage increase in women's

unemployment rate (10.2 percent) was significantly different at a 10 percent level

from the percentage increase in men's unemployment rate (4.0 percent). This

suggests that the effect of the redesign was relatively greater for women than for

men. Those 65 and older also had a larger percentage increase in their

unemployment rate (52.3 percent) compared to the rest of the population (6.8

percent).

• Statistical tests of the relative difference in the estimated unemployment rates

suggest that, while the revised questionnaire and collection procedures affected men

and women's unemployment rates differently, the effect of these revisions were

essentially the same for all women regardless of their race.
9

• Examination of the relative ratio of the unemployment rate in the Parallel Survey to

the CPS over time tentatively suggests that, compared to the CPS, the Parallel

Survey more completely identified individuals seeking seasonal employment.

• Graphing of the relative ratios of the unemployment rates in the Parallel Survey and

the CPS for several major demographic groups tentatively indicates that the larger

difference between surveys in the summer is at least partially due to adult women

and teenagers.

• The higher level of unemployment as measured by the Parallel Survey, and thus the

larger unemployment rate, was primarily accounted for by the larger estimated

number of individuals looking for work (as opposed to a larger number of

individuals being on layoff and expecting recall).

Employment-to-Population Ratio

• The proportion of the population working -- the employment-to-population ratio --

were not statistically different between surveys for the year 1993. However, the

overall estimate masked differences by gender. The estimated ratio for men was

significantly lower in the Parallel Survey (69.3 percent) than in the CPS (69.9

percent), while the estimated ratio for women was significantly higher (Parallel

Survey, 54.9 percent ,versus CPS, 54.2 percent).

• Statistical testing of the relative differences between surveys established that the

effect of the redesign on men and women's estimated employment-to-population

ratios did not differ by race or ethnicity.

• The smaller employment-to-population ratio for men measured in the Parallel

Survey was primarily attributable to the smaller estimated number of men who were

temporarily absent from a job. The Parallel Survey measured 15.9 percent fewer

men who were temporarily absent from a job than did the CPS.

• As for men, the Parallel Survey measured fewer women who were temporarily

absent from a job than did the CPS. However, the Parallel Survey also measured

more women who were at work during the reference week. The increase in the

estimated number of women at work was larger than the decrease in the estimated

number of women who were temporarily absent from a job; therefore, the

employment-to-population ratio was significantly higher for women in the Parallel

Survey than in the CPS.
10

Labor Force Participation Rate

• The 1993 annual labor force participation rate -- the percentage of the population

that is either employed or unemployed -- was significantly higher in the Parallel

Survey (66.6 percent) than in the CPS (66.2 percent). Again, however, the overall

higher rate masks differences by gender. The estimated labor force participation

rate for men was significantly lower in the Parallel Survey (74.8 percent ) than in

the CPS (75.2 percent), and the estimated labor force participation rate for women

was significantly higher (Parallel Survey, 59.1 percent, versus CPS, 57.9 percent).

• Teenagers and older workers both had significantly higher estimated labor force

participation rates in the Parallel Survey, compared with those from the CPS.
11

II. Unemployment Rates

A. Comparison of the Total Unemployment Rates

As mentioned in the highlights, the 1993 annual unemployment rate as measured by the

Parallel Survey (7.26 percent) was almost a half a percentage point higher than the annual

unemployment rate as measured by the CPS (6.80 percent). Table 2.1 presents annual,

quarterly, and 3-month moving average estimated unemployment rates for the entire labor

force. Graph 2.1 plots the 3-month moving average unemployment rates for both surveys

over time.7

 

7 Monthly estimates are not being presented or discussed due to the high degree of variance in the

monthly estimates from the Parallel Survey. For monthly estimates that are comparable to those obtained

from the redesigned CPS starting in January 1994, see "What Would the Unemployment Rate Have Been

Had the Redesign Current Population Survey Been in Place from September 1992 to December 1993?: A

Measurement Error Analysis," CPS Bridge Team Technical Report 1, by Stephen Miller.
12

Table 2.1

TOTAL UNEMPLOYMENT RATE

(UNEMPLOYED AS A PERCENTAGE OF THE LABOR FORCE AGE 16 AND OLDER)

Parallel Survey CPS Difference P-Value

1993 Annual Average

Jan. - Dec. 7.26 6.80 0.45* 0.00

1993 Quarterly

Averages

Jan. - Mar. 7.95 7.68 0.27 0.19

Apr. - Jun. 7.32 6.88 0.45* 0.02

Jul. - Sept. 7.15 6.57 0.58* 0.00

Oct. - Dec. 6.62 6.10 0.52* 0.01

1993 3-Month

Moving Averages

Jan. - Mar. 7.95 7.68 0.27 0.19

Feb. - Apr. 7.55 7.31 0.23 0.25

Mar. - May 7.37 6.95 0.41* 0.04

Apr. - June 7.32 6.88 0.45* 0.02

May - July 7.47 6.89 0.59* 0.00

June - Aug. 7.42 6.82 0.60* 0.00

July - Sept. 7.15 6.57 0.58* 0.00

Aug. - Oct. 6.83 6.36 0.47* 0.01

Sept. - Nov. 6.66 6.20 0.46* 0.01

Oct. - Dec. 6.62 6.10 0.52* 0.01

1992 4-Month Average

Sept.- Dec. 7.60 6.99 0.61* 0.00
13

 GRAPH 2.1

3- Month Moving Average Unemployment Rates, 1993

Rate

5.5

6

6.5

7

7.5

8

8.5

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Parallel Survey

CPS

As can be seen by examining the data in table 2.1, every quarterly and 3-month moving

average estimate of the unemployment rate was higher in the Parallel Survey than in the

CPS. However, as can be seen in graph 2.1, despite the higher unemployment rate in the

Parallel Survey, both surveys reflected the same general trend in the labor market. Both

the 3-month moving average and the quarterly data indicate that there was a steady

decline in the unemployment rate throughout 1993. The estimated unemployment rate

was significantly lower for the fourth quarter than it was for the first quarter in both

surveys, although the percentage decrease was smaller in the Parallel Survey than in the

CPS8.

Graph 2.2 plots, over time, the relative ratio between surveys, that is, the estimate from

the Parallel Survey divided by the estimate from the CPS, of the 3-month moving average

unemployment rates. Examination of the 3-month moving average data and graph 2.2

reveal that the difference between the estimated unemployment rates from the two surveys

increased throughout the spring of 1993, reached a peak in the summer, and declined

during the early fall. There also was a slight increase in the difference between the rates in

the 3-month moving average which included the months of November and December.

During the summer and late winter months, individuals are more likely to seek seasonal

employment. Consequently, the pattern observed in the relative difference in the 3-month

moving averages suggests that the Parallel Survey, compared to the CPS, may have more

 

8 The 3-month moving average rates and the quarterly data were not seasonally adjusted. However,

aggregating over several months should smooth the data and mitigate the effect of not seasonally adjusting

the monthly estimates. Furthermore, the underlying seasonal variation in the economy should be the same

for both surveys. Therefore, comparisons between the two surveys at a given point in time or across the

same time period, should not be confounded by seasonal variation in the economy.
14

completely identified individuals who were seeking seasonal employment. It is also

interesting to note that in the early part of the year there were no significant differences

between the Parallel Survey and the CPS.

 GRAPH 2.2

Relative Ratios of 3-Month Moving Average Unemployment

Rates in the Parallel Survey compared with the CPS, 1993

Ratio

(PS/CPS)

1.03

1.04

1.05

1.06

1.07

1.08

1.09

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

B. Comparisons for Specific Demographic Groups

In this section, we examine differences in the estimated unemployment rates for specific

demographic groups. Differences by gender are examined first, followed by differences

for race/ethnicity groups and differences by age. The relevant data are included in each

subsection. A single comprehensive table of the estimated unemployment rates by

demographic groups is provided in appendix B. The annual average estimated numbers of

unemployed individuals in each demographic category are also provided in a separate table

in Appendix B.

Unemployment Rates for Men and Women

Table 2.2 contains estimated annual average, quarterly, and 3-month moving average

unemployment rates for men and women. These data indicate that the estimated

unemployment rates for women were higher from the Parallel Survey than from CPS on an

annual average basis, in every quarter of 1993, and for 9 out of 10 of the moving

averages. In contrast, for men, the estimated unemployment rates on an annual average

basis and for the first two quarters of 1993 were not significantly different between the

surveys. The estimated unemployment rates for men, however, were higher in the Parallel

Survey for the third and fourth quarters of 1993. These estimates suggest that the

redesign may be differentially effecting men and women.
15

TABLE 2.2

UNEMPLOYMENT RATES FOR MEN AND WOMEN

(UNEMPLOYED AS A PERCENTAGE OF THE LABOR FORCE AGE 16 AND OLDER)

Men Women

Parallel CPS Difference Parallel CPS Difference

1993 Annual

Average

Jan.-Dec. 7.36 7.08 0.28 7.14 6.48 0.66*

1993 Quarterly

Averages

Jan.-Mar 8.26 8.46 -0.21 7.60 6.75 0.85*

Apr. - Jun. 7.48 7.19 0.29 7.14 6.50 0.64*

July - Sept. 6.94 6.48 0.47* 7.38 6.68 0.70*

Oct. - Dec. 6.77 6.19 0.58* 6.44 5.99 0.45*

1993 3-Month

Moving Averages

Jan. - Mar 8.26 8.46 -0.21 7.60 6.75 0.85*

Feb. - Apr. 7.85 8.08 -0.23 7.20 6.40 0.80*

Mar - May 7.57 7.55 0.02 7.13 6.24 0.89*

Apr. - June 7.48 7.19 0.29 7.14 6.50 0.64*

May - July 7.46 7.01 0.45* 7.49 6.75 0.75*

June - Aug. 7.25 6.81 0.44* 7.62 6.84 0.79*

July - Sept. 6.94 6.48 0.47* 7.38 6.68 0.70*

Aug. - Oct. 6.72 6.24 0.48* 6.96 6.50 0.46*

Sept. - Nov. 6.73 6.14 0.59* 6.59 6.28 0.31

Oct. - Dec. 6.77 6.19 0.58* 6.44 5.99 0.45*

One statistical means of assessing whether the redesign affected various demographic

groups differently is to examine the difference in the relative change of unemployment

rates between surveys. If there is no significant difference in the relative increase, the

conclusion would be that the changes in the CPS affect the demographic groups being
16

compared in the same way. The formula used to test for statistical differences among

demographic groups, along with the value of the test statistics and their p-values can be

found in Appendix C. Comparisons of the relative differences of men's and women's

unemployment rates between surveys (with the CPS rate being used as the base) indicate

that the difference in the annual unemployment rates was relatively larger for women than

for men. Specifically, the 10.1 percent difference in women's unemployment rates

between surveys was significantly larger than the 4.0 percent difference in men's

unemployment rate. This finding suggests that the redesign did affect women relatively

more than men.

The effect of the redesign on men and women can also be examined by plotting the

relative differences in the 3-month moving averages. In addition to providing insight into

the effect of the redesign on men and women, examination of the relative differences can

also shed light on the overall differences seen between the surveys. Graph 2.3 plots the

relative difference in the 3-month moving averages over time for men and women.

 GRAPH 2.3

Relative Ratios Between Surveys 

 for Men's and Women's 3- Month Moving Average

Unemployment Rates, 1993

Ratio

(PS/CPS)

0.95

1

1.05

1.1

1.15

JanMarFebAprMarMayAprJunMayJulJunAugJulSepAugOctSepNovOctDec

Men

Women

The graph of the relative ratio between surveys indicates that, with the exception of the

end of the year, the relative increase in women's unemployment rate was larger than the

relative increase for men's. The graph also indicates that men's and women's

unemployment rates followed a very different pattern in 1993. Women's 3-month moving

average unemployment rates partially followed the seasonal pattern seen for the labor

force as a whole, whereas men's 3-month moving average unemployment rate did not.

Specifically, for women, the plot of the differences between surveys had a "hump" during

the summer months (increasing after the April/June 3-month moving average and

decreasing after the July/September 3-month moving average), and rose slightly again at

the end of the year. In contrast, for men, the difference between surveys increased

steadily. The existence of a seasonal pattern in the difference between surveys of women's

3-month moving averages and the apparent lack of a seasonal pattern in men's averages
17

suggests, that compared to the CPS, the Parallel Survey may have captured more women

searching for seasonal employment. However, the steady increase in the difference

between surveys in men's 3-month moving averages, combined with the large differences

in women's 3-month moving averages early in 1993, suggest that the parabolic shape of

the difference in 3-month moving average unemployment rates seen for the entire labor

force in graph 2.2 may also be partially attributable to the mathematical averaging of men's

and women's 3-month moving average rates.

Another relationship for men's and women's unemployment rates that is interesting to

explore is the magnitude of the difference in the unemployment rates between surveys and

the level of the CPS unemployment rate. The quarterly data suggest that for women, the

higher the unemployment rate in the CPS, the larger the difference is between surveys.

The quarterly data suggest the reverse for men; the higher the unemployment rate in the

CPS, the smaller the difference is between surveys. Graphs 2.4 and 2.5 plot for men and

women, respectively, the difference in the unemployment rates between surveys against

the CPS unemployment rate. The graphs lend credence to the hypothesized relationship

between the level of the unemployment rate and the magnitude of the difference between

surveys for men and women. In the future, statistical testing will be done to further

explore these possible relationships. In addition, attempts will be made to disentangle

seasonal effects from the effect of different levels of unemployment.

 GRAPH 2.4

 MEN'S DIFFERENCE IN UNEMPLOYMENT RATES BETWEEN SURVEYS 

COMPARED TO THE CPS UNEMPLOYMENT RATE

CPS UNEMPLOYMENT RATE

D

I

F

F

I

N

U

N

R

A

T

E

S

-0.4

-0.2

0

0.2

0.4

0.6

0.8

5.5 6 6.5 7 7.5 8 8.5 9
18

 GRAPH 2.5

WOMEN'S DIFFERENCE IN UNEMPLOYMENT RATES BETWEEN SURVEYS 

COMPARED TO THE CPS UNEMPLOYMENT RATE

CPS UNEMPLOYMENT RATE

D

I

F

F

I

N

U

N

R

A

T

E

S

-0.5

0

0.5

1

5.5 5.7 5.9 6.1 6.3 6.5 6.7 6.9 7.1 7.3 7.5

In summary, statistical testing and graphical techniques establish that the redesigned

questionnaire and automated collection procedures resulted in the estimated

unemployment rate for women being increased relatively more than for men.

Furthermore, examination of the quarterly data and graphical analysis of the 3-month

moving averages suggests that, as the unemployment rate increases, the difference

between the CPS and the Parallel Survey unemployment rates for women also increases.

These findings suggest, therefore, that, all other things remaining equal, areas and time

periods with higher female unemployment rates would be relatively more effected by the

redesign than would areas and time periods with lower female unemployment rates.

Unemployment Rates for Race and Ethnic Groups

Table 2.3 contains unemployment rates for various race and ethnic groups. The data are

further subdivided by gender. The data for Hispanics, and Other Races should be viewed

very cautiously due to small sample sizes. Comparison of Hispanic data between surveys

is further confounded by differences in the use of Spanish questionnaires and translation

techniques in primarily Spanish speaking households.9

 

9 Parallel Survey interviews from the centralized phone facility in Tucson, Arizona were conducted with

a Spanish questionnaire when needed. Field observations of the Parallel Survey also established that the

Spanish questionnaire was sporadically used during personal visits. In the CPS interviews, the

interviewers translated the labor force questions into Spanish themselves or relied on another member of

the household to translate for them (McKay, 1993).
19

TABLE 2.3

1993 AVERAGE UNEMPLOYMENT RATES BY RACE AND ETHNIC GROUPS

(UNEMPLOYED AS A PERCENTAGE OF THE LABOR FORCE AGE 16 AND OLDER)

Parallel

Survey

CPS Difference P-value

Whites 6.30 5.96 0.34* 0.00

 Men 6.45 6.23 0.22 0.19

 Women 6.12 5.62 0.50* 0.00

Blacks 14.28 12.96 1.31* 0.01

 Men 14.86 13.89 0.97 0.22

 Women 13.71 12.05 1.66* 0.03

Other Races 8.90 8.19 0.71 0.28

 Men 8.69 8.61 0.08 0.93

 Women 9.14 7.68 1.46* 0.04

Hispanic 11.76 10.59 1.17* 0.03

 Men 10.35 10.44 -0.10 0.88

 Women 13.83 10.81 3.02* 0.00

Examination of the data by race indicates that whites and blacks both had significantly

higher unemployment rates in the Parallel Survey than in the CPS. Statistical testing

indicates, however, that the relative differences in the unemployment rates for blacks,

whites, and other races were not statistically different from each other. Therefore, it can

be concluded that the redesign did not differentially affect the unemployment rate of any

one particular race group.

When unemployment rates were examined by gender within race categories, it is seen that

women, regardless of their race, had significantly higher unemployment rates in the

Parallel Survey than in the CPS. However, comparisons among women of various races

indicate that their relative increases were not statistically different from each other. This

finding, in combination with the difference found by gender when the data were not

disaggregated by race, suggests that the revised questionnaire and collection procedures
20

affect men's and women's unemployment rates differently, but the effect of these revisions

were essentially the same for all women, regardless of their race.10

Unemployment Rates for Age Groups

Table 2.4 contains unemployment rates for adults, adult men, adult women and teenagers.

It also contains unemployment rates for adults further subdivided by age. Again some of

this data should be viewed very cautiously due to small sample sizes.

TABLE 2.4

1993 AVERAGE UNEMPLOYMENT RATES FOR SPECIFIC AGE GROUPS

Parallel

Survey

CPS Difference P-value

Adults 6.47 6.11 0.36* 0.01

 Adult Men 6.58 6.35 0.23 0.18

 Adult Women 6.34 5.83 0.50* 0.00

Teenagers 20.61 19.03 1.58* 0.05

Age (in years)

 20-24 10.74 10.46 0.29 0.54

 25-34 7.25 6.83 0.43* 0.09

 35-44 5.66 5.45 0.21 0.36

 45-54 5.04 4.72 0.32 0.22

 55-64 4.95 4.63 0.32 0.38

 65 and older 4.72 3.10 1.62 0.01

Examination of the data in table 2.4 indicates that differences in the unemployment rates

between surveys for all adults, adult men, and adult women displayed the same pattern as

was observed in the entire labor force. For adults, the unemployment rate was estimated

 

10 The relative increase in the unemployment rate for Hispanic women was statistically larger than the

relative increase in the unemployment rate for white women. However, the estimates for Hispanic women

were extremely variable and subject to the non sampling error discussed in footnote 8. It also should be

noted that, for the purposes of the CPS, Hispanics are an ethnic group. Hispanics can be of any race.
21

to be statistically higher in the Parallel Survey than in the CPS. This difference averaged

.36 percentage point throughout 1993. Statistical testing revealed that the measured

effect was relatively larger for adult women than for adult men. Plots of the relative ratios

of the 3-month moving average unemployment rates from the two surveys indicate that

the ratios for adult men and adult women followed the same pattern seen for all males and

females in the labor force. Specifically, for adult women the difference between surveys

increased during the summer, fell in the early fall, and increased slightly again in the late

fall. The relative ratio for adult men increased fairly steadily throughout 1993. The plot

of adult men's relative ratio did not have a peak in the summer months. (See Graph 2.6)

 GRAPH 2.6

Relative Ratios Between Surveys 

 in Adult Men's and Adult Women's 3- Month Moving

Average Unemployment Rates, 1993

Ratio

(PS/CPS)

0.95

1

1.05

1.1

1.15

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Adult Men

Adult Women

Two other age groups that had noteworthy differences between the surveys in their

estimated unemployment rates were individuals 65 years and older (older workers) and

teenagers. Both of these groups had significantly higher unemployment rates in the

Parallel Survey than in the CPS. However, only older workers had a percentage increase

in their unemployment rate that was significantly different than the percentage increase

observed for the population as a whole. Those 65 and older had a 52.3 percent higher

unemployment rate in the Parallel Survey, compared with a 6.8 percent higher

unemployment rate for the population as a whole. Quarterly data for teenagers and those

65 and older are presented in Table 2.5. The relative difference between surveys in the 3-

month moving average unemployment rates for teenagers and those 65 and older are

presented in graph 2.7 and graph 2.8 respectively.11

 

11 Since those 65 and older had a larger percentage increase in their unemployment between surveys than

any other major demographic group, the plot of the relative ratio between surveys for older workers is

plotted on a different scale than the graphs of the relative differences for the other demographic groups.

.
22

TABLE 2.5

QUARTERLY UNEMPLOYMENT RATES FOR

TEENAGERS AND OLDER WORKERS

Teenagers Older Workers

Parallel CPS Difference Parallel CPS Difference

1993 Quarterly

Averages

Jan.-Mar 21.68 21.02 0.66 5.85 3.68 2.17*

Apr - Jun. 22.60 21.16 1.45 4.60 2.76 1.84*

Jul. - Sept. 18.40 16.82 1.57 5.13 3.12 2.02*

Oct. - Dec. 20.01 17.49 2.52* 3.33 2.87 0.46

 GRAPH 2.7

Relative Ratios Between Surveys 

 in Teenagers' 3- Month Moving Average Unemployment

Rates, 1993

Ratio

(PS/CPS)

0.95

1

1.05

1.1

1.15

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.
23

 GRAPH 2.8

Relative Ratios Between Surveys 

 in Older Workers' 3- Month Moving Average

Unemployment Rates, 1993

Ratio

(PS/CPS)

1.14

1.24

1.34

1.44

1.54

1.64

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

It should be noted that the relatively large percentage difference in unemployment rates for

those 65 and older is at least partially attributable to the fact the unemployment rate for

older workers is relatively low in both surveys. However, in comparison to other

demographic groups, older workers do have the largest percentage difference in the

unemployment rates between surveys. Furthermore, the unemployment rate for those 65

and older was significantly higher in the Parallel Survey than in the CPS in three of the

four quarters of 1993. In contrast, for teenagers, the difference between the surveys was

only significant in one of the quarters.

Examination of the relative ratio graphics indicate that for teenagers the difference

between surveys was largest for the June to August and October to December 3-month

moving averages. The relative ratios were 1.11 for each of these 3-month moving

averages12. In contrast, the relative ratios for individuals who were 65 and older actually

dipped slightly during the summer months and declined precipitously during the fall.

Overall, examination of the relative ratios of the 3-month moving average unemployment

rates for the major demographic groups that had significant differences between the

surveys suggest that the increases seen for the entire labor force during the summer and

late fall were primarily due to differences for adult women and teenagers.13

 

12 The June to August 3-month moving average is split between the second and third quarter which is

why the 3-month moving average could be statistically different between surveys while the two quarters

were not. The p-value for the difference between surveys in the June to August 3-month moving average

for teenagers was .07.

13 Statistical comparisons of the June-August 3-month moving average unemployment rates (the 3-month

moving average with the largest relative difference for teenagers) indicate that the relative difference
24

C. DISCUSSION OF POSSIBLE CAUSES OF DIFFERENCES IN THE

UNEMPLOYMENT RATES

COMPONENTS OF UNEMPLOYMENT

The unemployed are made up of two groups; those who are looking for work and those

who are on layoff. To gain insight into how the Parallel Survey obtained a higher

unemployment rate than the CPS, it is useful to examine what proportion of the difference

in unemployment each of these two components constituted. Table 2.6 displays the

number individuals looking for work and the number of individuals on layoff for both

surveys. Table 2.6 also contains the difference between the two surveys in the number of

individuals looking or on layoff, what percentage of the total difference in unemployment

these two differences constituted (that is, the difference in the number of individuals on

layoff {or looking for work}, divided by the difference between surveys in the total

number of unemployed), and for each component of unemployment, the ratio of the

number of individuals in the Parallel Survey to the number of individuals in the CPS.

From these later ratios, the percentage change in the estimated number of individuals in

each survey can easily be seen. 14

The data in table 2.6 indicate that the higher levels of unemployment in the Parallel Survey

among women, teenagers, and older workers, along with what difference there was in

men's unemployment rate, were primarily attributable to the larger estimated number of

individuals "looking for work" in the Parallel Survey. Specifically, the larger number of

jobseekers in the Parallel Survey accounted for 82.8 percent of the higher level total

employment, 72.8 percent of the higher level for women, 75.3 percent of the higher level

for teenagers, and 63.8 percent of the higher level for older workers. For men, the higher

unemployment rate in the Parallel Survey is entirely attributable to the greater number of

men classified as "looking for work". The number of men classified as being

"unemployed on layoff" was actually 2.5 percent lower in the Parallel Survey than in the

CPS. The larger number of individuals classified as jobseekers in the Parallel Survey is

primarily attributable to a combination of automation of the collection process and

changes in the questionnaire.15

 

between surveys for adult men, adult women, and teenagers were not statistically different from each

other. However, sample sizes for the 3-month moving averages are relatively small, which increases the

variance of the estimates, and thus, the tests may not be powerful or robust enough to detect statistical

differences in the estimates. The p-value for the difference between adult men and adult women was .25.

14 To obtain the percentage change in the estimated number of individuals, subtract the ratio from 1 and

multiply the absolute value by 100.

15 Differences in the percentage of the two surveys conducted from centralized CATI facilities could also

affect the estimated number of individuals looking for work.
25

TABLE 2.6

1993 ANNUAL AVERAGE OF THE NUMBER OF INDIVIDUALS IN THE

SUBCATEGORIES OF THE UNEMPLOYED

(numbers in thousands)

Parallel Survey

(PS)

CPS Difference

(PS-CPS)

Ratio

(PS/CPS)

Number Percent Number Percent Number Percent

Total unemployed 9,359 100.0 8,714 100.0 645 100.0 1.07

 Looking for work 8,157 87.2 7,623 87.5 534 82.8 1.07

 On Layoff 1,202 12.8 1,091 12.5 111 17.2 1.10

Men--unemployed 5099 100.0 4928 100.0 171 100.0 1.03

 Looking for work 4,382 85.9 4,193 85.1 189 110.5 1.05

 On Layoff 717 14.1 735 14.9 -18 -10.5 0.98

Women--unemployed 4259 100.0 3785 100.0 474 100.0 1.13

 Looking for work 3774 88.6 3,429 90.6 345 72.8 1.11

 On Layoff 485 11.4 356 9.4 129 27.2 1.36

Teenagers--unemployed 1,484 100.0 1,302 100.0 182 100.0 1.14

 Looking for work 1,397 94.1 1,260 96.8 137 75.3 1.11

 On Layoff 87 5.9 42 3.2 45 24.7 2.07

65 and older--unemployed 179 100.0 110 100.0 69 100.0 1.64

 Looking for work 140 78.2 96 87.3 44 63.8 1.45

 On Layoff 39 21.8 14 12.7 26 36.2 2.79

QUESTIONNAIRE CHANGES AND AUTOMATION EFFECTS

Computer-assisted interviewing virtually eliminates the possibility of questions being

incorrectly skipped or asked in error. Furthermore, automation of the questionnaire

makes it more difficult to take inappropriate short cuts during an interview. Questions are

also more likely to be asked as worded with an automated questionnaire, so that

underlying concepts are more accurately and consistently conveyed to respondents.

The questionnaire itself was reworded to provide a broader and more uniform context for

all respondents. In the CPS, the labor force portion of the interview starts with the

question, "What were you doing most of LAST WEEK -- working or something else?"
26

This question has been criticized for several reasons.16 One problem with the question is

that it does not necessarily focus respondents' attention on the primary intention of the

survey. BLS really is not interested in what respondents did most of last week, but rather

whether they did any activities related to the job market.

Another problem with the question is that depending on interviewers' inflection, the

question could have two different literal meanings. If the emphasis is placed on the end of

the phrase "most of, " respondents could interpret the question as asking what activity

took up the most time last week (to which the answer might very well be sleeping). On

the other hand, if the phrase "most of" is said without an emphasis on either word,

respondents could interpret the question to be asking what the respondent did four out of

the seven days last week. Regardless of which interpretation respondents use, neither

would necessarily induce them to report part-time or intermittent work. The possibility of

the initial labor force question not focusing respondents on labor market activities in

combination with the phrase "most of last week" could cause some respondents to believe

that the survey is only interested in individuals search for full-time permanent employment.

This impression could be reinforced by the manner in which interviewers may customize

the initial labor force question. Interviewers are instructed to tailor the first labor force

question depending on their perception of respondent's situations. For example, a small

sample of interviews suggests that if a woman appeared to be a homemaker, the question

was typically asked, "What were you doing most of last week -- working, keeping house

or something else?" If respondents appear to be relatively young, the question was usually

tailored to be, "What were you doing most of last week -- working, going to school or

something else?" Moreover, the sample of interviews indicated that some apparent

homemakers and students received the question without the word "working".17

Respondents who did not appear to be homemakers or students were asked, "What were

you doing most of last week -- working or something else?"18

The first labor force question was originally introduced into the survey as an "icebreaker"

question to help respondents feel comfortable and allow them an opportunity to provide

their primary group identification. However, analysis of data on respondents' path through

the questionnaire produced by the Questionnaire Evaluation Work Group, indicates that

 

16 U. S. Bureau of Labor Statistics and U. S. Bureau of the Census (1986), Report of the BLS-Census

Bureau Questionnaire Design Task Force.

17 The interviewers' manual actually instructs interviewers to exclude the word "working" in some

instances. For example, if a respondent appears to be a homemaker the manual indicates that the

interviewers should ask "What were you doing most of last week, keeping house or something else?" If an

individual appears to be a student the manual indicates that interviewers should ask "What were you

doing most of last week, going to school or something else?" Therefore, the inclusion of the word

"working" for apparent homemakers and students is slightly at variance with the interviewers' manual.

18 For more information on the tailoring of the initial labor force question refer to Rothgeb (1994).
27

50.8 percent of male jobseekers are identified on this initial labor force question compared

with 32.5 percent of female jobseekers.19 These data indicate that not only are many

jobseekers identified at the first question, but also the first question differentially affects

the responses from men and women. The combination of the initial question wording and

tailoring in the CPS may be sending a message to women (and others) that the CPS is not

asking about their search for more casual, intermittent or part-time work and thus cause

them to be misclassified. The Parallel Survey has no equivalent question or any labor

force questions that are customized based on a respondent's appearance.

In addition to reducing misclassification through the elimination of the initial labor force

question, the possibility of misclassification was also reduced in the Parallel Survey

through the revision of the question about layoffs. In the CPS, the inquiry about layoffs is

a long complex question that simultaneously asks about temporary absences and layoffs

from jobs. Previous research indicates that this question is awkward for interviewers to

ask and frequently misunderstood by respondents20. In the Parallel Survey, to address

these concerns, inquiries about temporary absences and layoffs were split into two

questions (See Appendix A for a comparison of the wording of the layoff questions in the

Parallel Survey and in the CPS.).

Besides splitting the temporary absent and layoff question, improvements in the

measurement of layoffs were also obtained through several modifications to the follow-up

question asking why an individual was absent from work. Perhaps the most noteworthy

change was the restructuring and relabeling of the CPS response categories. The CPS

categories of "temporary layoff" and "indefinite layoff" were combined into a single "on

layoff" category in the Parallel Survey, and a category "slack work/ business conditions"

was added. The marking of the "slack work/business conditions" category would place

individuals on a path through the questionnaire that could potentially classify them as "on

layoff" or "looking for work." It is not completely clear how responses that were

classified as "slack work/business conditions" in the Parallel Survey were classified in the

CPS. If, however, they were placed in the "other" category in the CPS, these individuals

would be classified as employed (with a job, but not at work). Consequently, these

individuals would be precluded from being asked the unemployment questions and thus

potentially being classified as unemployed.

Finally, with respect to the measurement of jobseekers, there was a concern that the CPS

question inquiring whether an individual had looked for work in the last four weeks might

be interpreted by respondents as requiring an intensive job search over an extended period

 

19 Rothgeb (1994).

20 Rothgeb, J. (1982) Summary of July Follow-up of the Unemployed. Unpublished Bureau of the Census

memorandum. Palmisano, M. (1989) Respondents Understanding of Key Labor Force Concepts Used in

the CPS, in Proceedings of the Section on Survey Research Methods, Alexandria, VA: American

Statistical Association.
28

of time. If the CPS "looking for work" question were interpreted by respondents too

narrowly, individuals would be incorrectly excluded from being classified as unemployed.

To broaden the group of individuals who might be classified as unemployed, the question

inquiring if an individual had looked for work was changed from, "Have you been looking

for work during the past 4 weeks?" in the CPS to, "Have you been doing anything to find

work during the last 4 weeks?" in the Parallel Survey.

Due to complicated skip patterns embodied in the questionnaire, it was not possible to

conduct the Parallel Survey with paper and pencil On the other hand, due to cost

constraints, the CPS questionnaire was not administered using a laptop computer.

Therefore, it is not possible to observe the pure effect of automating the collection process

or completely disentangle the effect of automating the questionnaire from the effect of

revisions to the questionnaire. However, examining a test panel of interviews that were

eligible to be conducted from centralized facilities, and thus both surveys were automated,

the Mode Effects Work Group was able to establish that the revised questionnaire did

result in a significantly higher unemployment rate for blacks, black women, and a

marginally significantly higher unemployment rate for women as a whole.21 These results

should be viewed with caution because the test panels were small, not representative of

the total population, and not all interviews that were eligible to be conducted from the

centralized facility were actually done there. Furthermore, all interviews conducted from

centralized facilities were with households that had been contacted in person previously

(e.g., all interviews conducted from centralized facilities were month-in-sample 2's through

4's or 6's through 8's), and the initial labor force question in the CPS was not customized

based on interviewers assessment or recollection of respondents' appearance.

Nevertheless, the data suggest that the combination of the elimination of the initial labor

force question with its concomitant customizing by interviewers, the splitting of the layoff

and temporarily absent inquires into two questions, the changes to the follow-up question

asking why individuals were absent from jobs, and the broadening of the question

inquiring if an individual looked for work in the last 4 weeks all contributed to a higher

unemployment rate in the Parallel Survey.

 

21 Thompson (1994)
29

III. Employment to Population Ratios

A. Comparison of the Total Employment-To-Population Ratios

Table 2.7 contains annual, quarterly, and 3-month moving average estimates of the

proportion of the population working -- a statistic known as the employment-topopulation ratio. Graph 2.9 contains plots of the estimated 3-month moving average

employment-to-population ratios for both surveys. As can been seen by examining the

data in table 2.7 and graph 2.9, the estimated employment-to-population ratios were not

significantly different between surveys (for any time period examined).

TABLE 2.7

TOTAL EMPLOYMENT-TO-POPULATION RATIOS

(EMPLOYED AS A PERCENTAGE OF THE CIVILIAN POPULATION AGE 16 AND OLDER)

________________________________________________________________________

Parallel Survey CPS Difference P-Value

1993 Annual

Average

Jan. - Dec. 1993 61.80 61.68 0.11 0.61

1993 Quarterly

Average

Jan. - Mar 60.93 60.55 0.38 0.21

Apr. - June 61.89 61.74 0.15 0.60

July - Sept. 62.20 62.30 -0.10 0.72

Oct. - Dec. 62.16 62.14 0.02 0.94

1993 3-Month

Moving Averages

Jan. - Mar. 60.93 60.55 0.38 0.21

Feb. - Apr. 61.19 60.81 0.38 0.20

Mar - May 61.41 61.23 0.18 0.54

Apr. - June 61.89 61.74 0.15 0.60

May - July 62.23 62.29 -0.07 0.81

June - Aug. 62.44 62.52 -0.08 0.78

July - Sept. 62.20 62.30 -0.10 0.72

Aug. - Oct. 62.07 62.10 -0.03 0.93

Sept. - Nov. 62.10 62.02 0.08 0.79

Oct.- Dec. 62.16 62.14 0.02 0.94
30

 GRAPH 2.9

3-Month Moving Average Employment - to-Population Ratios, 1993

Ratio

60

60.5

61

61.5

62

62.5

63

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Parallel Survey

CPS

B. Comparisons for Specific Demographic Groups

Although there were no significant differences in estimated employment-to-population

ratios for the entire population, we examined differences for selected demographic

groups. Differences by gender are examined first, followed by differences for

race/ethnicity groups and differences by age groups. The relevant data are included in

each subsection. A single comprehensive table of estimated employment-to-population

ratios by demographic groups along with estimates of the average number of employed

individuals in 1993 by demographic group are provided in Appendix B.

Employment-to-Population Ratios for Men and Women

The lack of statistically significant differences in the employment-to-population ratio for

the entire population masked differences by gender. As can be seen by examining the

annual averages presented in Table 2.8 the ratio for men as measured by the Parallel

Survey was lower than the ratio measured in the CPS at a statistically significant level,

while the ratio for women as measured by the Parallel Survey was higher than that

measured by the CPS at a statistically significant level. Furthermore, the relative

increase in the employment-to-population ratio for women (1.01 with the CPS rate being

used as the base) was statistically different from the relative decrease for men (.99).
31

TABLE 2.8

1993 AVERAGE EMPLOYMENT TO POPULATION RATIOS BY GENDER

(EMPLOYED AS A PERCENTAGE OF THE CIVILIAN POPULATION AGE 16 AND OLDER)

Parallel Survey CPS Difference P-Value

Total 61.80 61.68 0.11 0.61

 Men 69.32 69.88 - 0.57* 0.02

 Women 54.90 54.16 0.74* 0.01

Table 2.9 contains quarterly and 3-month moving average employment-to-population

ratio estimates for men and women. Graph 2.10 contains plots of the estimated 3-month

moving average employment-to-population ratios for men in the two surveys, while

graph 2.11 plots over time the relative ratio between the two surveys. The same plots for

women are presented in graph 2.12 and 2.13.
32

TABLE 2.9

QUARTERLY AND 3-MONTH MOVING AVERAGE

EMPLOYMENT-TO-POPULATION RATIOS FOR MEN AND WOMEN

(EMPLOYED AS A PERCENTAGE OF THE CIVILIAN POPULATION AGE 16 AND OLDER)

________________________________________________________________________

Men Women

Parallel CPS Difference Parallel CPS Difference

1993 Quarterly

Averages

Jan.-Mar 67.77 68.32 -0.55 54.66 53.43 1.23*

Apr. - Jun. 69.34 70.09 -0.75* 55.05 54.07 0.98*

July - Sept. 70.39 71.06 -0.67* 54.67 54.26 0.42

Oct. - Dec. 69.75 70.06 -0.30 55.19 54.87 0.32

1993 3 Month

Moving Average

Jan. - Mar 67.77 68.32 -0.55 54.66 53.43 1.23*

Feb. - Apr. 68.10 68.69 -0.59 54.85 53.59 1.26*

Mar - May 68.60 69.29 -0.69* 54.82 53.84 0.98*

Apr. - June 69.34 70.09 -0.75* 55.05 54.07 0.98*

May - July 70.15 70.92 -0.77* 54.95 54.38 0.58

June - Aug. 70.55 71.35 -0.80* 54.99 54.41 0.58

July - Sept. 70.39 71.06 -0.67* 54.67 54.26 0.42

Aug. - Oct. 70.00 70.64 -0.64* 54.80 54.26 0.54

Sept. - Nov. 69.75 70.21 -0.45 55.07 54.50 0.56

Oct. - Dec. 69.75 70.06 -0.30 55.19 54.87 0.32

________________________________________________________________________
33

 GRAPH 2.10

3-Month Moving Average Employment-to-Population Ratios for Men, 1993

Ratio

67

67.5

68

68.5

69

69.5

70

70.5

71

71.5

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Parallel Survey

CPS

 GRAPH 2.11

Relative Ratios Between Surveys 

 in Men's 3-Month Moving Average 

Employment-To-Poulation Ratios, 1993

Ratio

(PS/CPS)

0.985

0.988

0.991

0.994

0.997

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.
34

 GRAPH 2.12

3-Month Moving Average Employment-to-Population Ratios for Women, 1993

Ratio

53.3

53.6

53.9

54.2

54.5

54.8

55.1

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Parallel Survey

CPS

 GRAPH 2.13

Relative Ratios Between Surveys 

 in Women's 3- Month Moving Average 

Employment-To-Poulation Ratios, 1993

Ratio

(PS/CPS)

0.999

1.009

1.019

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Examination of the data and the graphs indicate that for women the estimated differences

between surveys were largest during the first half of the year. Only in the first and

second quarter did women have significantly higher employment-to-population ratios in

the Parallel Survey than in the CPS. In contrast, men had significantly lower

employment-to-population ratios in the Parallel Survey for the Spring and Summer

quarters. Furthermore, for men, the largest difference between surveys in the 3-month

moving average occurred for June to August.
35

Employment-to-Population Ratios for Race and Ethnic Groups

Table 2.10 contains estimates of the employment-to-population ratios for major race and

ethnic groups. Statistical testing revealed that the relative difference in the employmentto-population ratios for blacks, whites, other race groups, and Hispanics were not

statistically different from each other. In addition, neither the relative increase for

women or the relative decrease for men in the employment-to-population ratios varied

significantly by race. These findings imply that the revised questionnaire and collection

procedures yielded higher estimated employment-to-population ratios for women and

lower estimated ratios for men, but the effects of the revision did not differentially effect

men or women of various races.

TABLE 2.10

1993 AVERAGE EMPLOYMENT-TO-POPULATION RATIOS

BY RACE AND ETHNICITY

(EMPLOYED AS A PERCENTAGE OF THE CIVILIAN POPULATION AGE 16 AND OLDER)

Parallel

Survey

CPS Difference P-value

Whites 63.00 62.77 0.23 0.34

 Men 70.83 71.36 -0.53* 0.05

 Women 55.70 54.76 0.94* 0.00

Blacks 53.40 54.40 -1.01 0.25

 Men 57.49 59.00 -1.52* 0.09

 Women 50.03 50.62 -0.59 0.60

Other Races 60.50 59.60 0.90 0.67

 Men 69.22 67.93 1.28 0.64

 Women 52.63 52.09 0.55 0.82

Hispanic 59.74 58.94 0.80 0.44

 Men 72.64 71.61 1.03 0.59

 Women 47.01 46.43 0.58 0.74
36

Employment-to-Population Ratios for Specific Age Groups

Table 2.11 contains estimates of the annual average employment-to-population ratios for

all adults, adult men, adult women and teenagers. The estimates for adults are further

subdivided by age. Some of these estimates should be viewed very cautiously due to

small sample sizes.

TABLE 2.11

1993 AVERAGE EMPLOYMENT-TO-POPULATION RATIOS

FOR SPECIFIC AGE GROUPS

Parallel

Survey

CPS Difference P-value

Adults 63.20 63.15 0.05 0.84

 Adult Men 71.38 72.04 -0.65* 0.01

 Adult Women 55.75 55.05 0.69* 0.03

Teenagers 42.88 41.80 1.08 0.18

Age (in years)

 20-24 69.34 69.03 0.31 0.83

 25-34 77.58 77.74 -0.16 0.86

 35-44 80.39 80.33 0.06 0.95

 45-54 77.50 77.76 -0.26 0.82

 55-64 53.10 53.80 -0.70 0.55

 65 and over 11.68 11.01 0.68 0.14

Examination of the estimates in Table 2.11 indicates that the differences in the

employment-to-population ratios between surveys for all adults, adult men, and adult

women displayed the same pattern as was observed for the entire labor force. The

estimated employment-to-population ratios in the two surveys for all adults combined

were not statistically different from each other. Again, however, the lack of a difference

for all adults masked differences by gender. The estimated employment-to-population

ratio for adult men was significantly lower in the Parallel Survey than in the CPS, while

adult women had a significantly higher estimated employment-to-population ratio in the

Parallel Survey compared to the CPS.

The estimated annual average employment-to-population ratios for the teenagers and

adults further subdivided by age group were not significantly different between the

surveys. However, annual averages could conceal differences for groups such as
37

teenagers and older workers who may be involved in more seasonal or intermittent

employment. Therefore, quarterly and 3-month moving average employment-topopulation ratios for teenagers and those 65 and older are presented in Table 2.12.

TABLE 2.12

QUARTERLY AND 3-MONTH MOVING AVERAGE

EMPLOYMENT-TO-POPULATION RATIOS FOR

TEENAGERS AND OLDER WORKERS

Teenagers Older Workers

Parallel CPS Difference Parallel CPS Difference

1993 Quarterly

Averages

Jan.-Mar 38.78 37.06 1.72 10.90 10.57 0.32

Apr. - Jun. 42.68 41.67 1.01 12.54 10.95 1.60*

July - Sep. 48.56 48.11 0.45 11.92 11.16 0.76

Oct. - Dec. 41.43 40.29 1.13 11.38 11.34 0.04

1993 3 Month

Moving Average

Jan. - Mar 38.78 37.06 1.72 10.90 10.57 0.32

Feb. - Apr. 38.59 37.50 1.09 11.12 10.58 0.54

Mar - May 39.28 38.49 0.79 11.77 10.77 1.00

Apr. - June 42.68 41.67 1.01 12.54 10.95 1.60*

May - July 47.67 47.01 0.66 13.05 11.12 1.93*

June - Aug. 50.99 50.37 0.62 12.68 11.13 1.54*

July - Sep. 48.56 48.11 0.45 11.92 11.16 0.76

Aug. - Oct. 44.50 43.45 1.05 11.48 11.27 0.20

Sept. - Nov. 41.37 40.11 1.26 11.39 11.36 0.03

Oct. - Dec. 41.43 40.29 1.13 11.38 11.34 0.04

The estimates in Table 2.12 indicate that teenagers did not have significantly higher

employment-to-population ratios in the Parallel Survey than in the CPS for any quarter

or 3-month moving average within 1993. In contrast, older workers had significantly

higher employment-to-population ratios in the Parallel Survey during the second quarter

of 1993 and the 3-month moving averages spanning late spring and summer.

C. DISCUSSION OF POSSIBLE CAUSES OF DIFFERENCES IN THE

EMPLOYMENT-TO-POPULATION RATIOS
38

COMPONENTS OF EMPLOYMENT

The employed are divided into two groups; those who are "at work" during the reference

week and those who are "temporarily absent from a job." As with the unemployment

rate, it is possible to gain insights into differences in the estimated employment-topopulation ratios between the two surveys by examining what proportion of the

difference in employment each of these two groups constituted. Table 2.13 contains, by

survey, the average number of individuals in 1993 "at work" and "temporarily absent

from a job" during the reference week. Table 2.13 also displays the difference between

the surveys in the number of individuals "at work" or "temporarily absent from a job";

the percent of the total employment difference accounted for by the two groups; and, for

each component of employment, the ratio of the number of individuals in the Parallel

Survey to the number of individuals in the CPS. From these latter ratios, the percentage

change between component of employment in the estimated number of individuals in

each survey can readily be seen.22

TABLE 2.13

1993 ANNUAL AVERAGE OF THE NUMBER OF INDIVIDUALS IN THE

SUBCATEGORIES OF THE EMPLOYED

(Numbers in thousands)

Parallel Survey

(PS)

CPS Difference

(PS-CPS)

Ratio

(PS/CPS)

Number Percent Number Percent Number Percent

Total employed 119,606 100.0 119,389 100.0 217 100.0 1.00

 At work 114,201 95.5 113,438 95.0 763 351.6 1.01

 Temp. absent 5,405 4.5 5,951 5.0 -546 -251.6 .91

Men--employed 64,202 100.0 64,727 100.0 -525 100.0 .99

 At work 61,872 96.4 61,957 95.7 -85 16.2 1.00

 Temp. absent 2,330 3.6 2,770 4.3 -440 83.8 .84

Women--employed 55,406 100.0 54,662 100.0 744 100.0 1.01

 At work 52,330 94.4 51,481 94.2 849 114.1 1.02

 Temp. absent 3,076 5.9 3,181 5.8 -105 -14.1 .97

 

22 To obtain the percentage change in the estimated number of individuals, subtract the ratio from 1 and

multiply the absolute value by 100.
39

The data in Table 2.13 suggest that the vast majority (83.8 percent) of the estimated

difference between the two surveys in the number of men employed (-525) results from

the fact that the estimated number of men temporarily absent from a job was less in the

Parallel Survey than in CPS. The annual average number of men estimated to be

temporarily absent from a job in the Parallel Survey was 16 percent less than in the CPS.

The effect of the estimated difference in temporary absences on men's employment is

consistent with the relative difference between the two surveys for men being largest

during the summer months when individuals are traditionally more likely to be on

vacation or involved in work where the attachment between employers and employees is

more tentative. The 3-month moving averages of men in the two employment categories

also indicate that temporary absences are causing the seasonal variation in the difference

between the two surveys in males employment-to-population ratios. Specifically, the

proportion of the total difference in men's employment accounted for by temporary

absences was largest for the 3-month moving averages that spanned the summer

months.23

The estimated number of women temporarily absent from a job was also lower in the

Parallel Survey. However, the estimated number of women at work in the reference

week was larger in the Parallel Survey than in the CPS. Specifically, the relative

increase in the estimated number of women at work in the Parallel Survey as compared

to CPS was 2 percent. Since the difference in the number of women "at work" between

the surveys was larger than the difference in the number of women who were

"temporarily absent from a job", the estimated employment-to-population ratio was

larger in the Parallel Survey than in the CPS.

QUESTIONNAIRE CHANGES AND AUTOMATION EFFECTS

As with the unemployment rates, the reason for observing differences in the

employment-to-population ratios between surveys was a combination of automating the

data collection process and questionnaire changes. With respect to the questionnaire,

 

23

PERCENTAGE OF MEN'S EMPLOYMENT DIFFERENCES TEMPORARY ABSENCES

CONSTITUTED

1993 3-MONTH MOVING AVERAGES

Percent

Jan.-Mar. 84.1

Feb.-Apr. 85.6

Mar.-May 61.8

Apr.-Jun. 51.9

May-Jul. 68.0

Jun.-Aug. 97.2

Jul.-Sep. 116.3

Aug.-Oct. 92.0

Sep.-Nov. 69.5

Oct.-Dec. 88.0
40

several of the changes that may have affected the unemployment rate also probably

affected women's employment-to-population ratio. Specifically, the initial labor force

question "What were you doing most of last week...", along with the interviewer

customization of this question, may have led some women to believe that the survey was

not asking about their part-time employment, especially if it were of a more informal or

intermittent nature. This assumption may have been reinforced by the phrase "not

counting work around the house" in the next question in the CPS -- "Did you do any

work at all last week, not counting work around the house." In contrast, respondents in

the Parallel Survey were specifically asked whether they did ANY work for pay in the

reference week. The Parallel Survey does not ask about respondents major activities

during the week. Furthermore, for individuals identified as living in a household with a

business or farm who did not indicate they were working for pay, a follow-up question

asks if they did any unpaid work. Examination of the path individuals took through the

questionnaire done by the Questionnaire Evaluation Work Group indicates that the larger

number of women identified as employed at the first at work question in the Parallel

Survey accounted for 46.6 percent of the larger number of women estimated to be

"working" in the Parallel Survey, while women identified as "working" at the question

about unpaid work accounted for 53.4 percent of the higher level of women's

employment in the Parallel Survey. It should be noted that the Modes Effect Work

Group was unable to detect a significant questionnaire effect. Therefore, all that can be

said conclusively is that the combination of the revised questionnaire and automated data

collection resulted in a higher level of employment among women in the Parallel Survey.

There also were questionnaire changes that could have affected the number of individuals

classified as temporarily absent in the Parallel Survey -- both men and women. For

example, in the CPS there is a response category "with a job not at work" for the "What

were you doing most of last week..." question. This is an awkward response category for

a question asking about activities, because this category does not indicate an activity. It

is unclear what sort of answers are coded as "with a job not at work", but it is suspected

that some respondents, especially those who perceive that it is socially desirable to be

employed, are providing vague answers from which interviewers infer that individuals

have jobs when in fact they do not. This could result in an inflated number of individuals

being classified as temporarily absent from a job. The Questionnaire Evaluation Work

group established that approximately 65 percent of those identified as temporarily absent

in CPS were identified at the "What were you doing most of last week..." question.

Individuals who were not identified as employed at the "What were you doing most of

last week..." question, or the "Did you do any work at all last week, not counting work

around the house" question, were asked "Last week, did you have a job from which you

were temporarily absent or on layoff?" As was noted in the discussion about

unemployment, this is a very complex question. In the Parallel Survey this question was

split into two questions, the first of which is "Last week did you have a job, either full or

part time? Include any job from which you were temporarily absent." Also, as was

previously discussed, the response categories for the "reason for absence" question were

restructured and expanded to include the category "slack work/business conditions." If

the "slack work/ business condition" category were marked in the Parallel Survey, an
41

individual would be precluded from being classified as employed, but has the possibility

of being classified as unemployed. In contrast, if, as previously explained, responses that

were marked as "slack work/business conditions" in the Parallel Survey were placed into

the "other" category in the CPS, these individuals could have erroneously been classified

as employed. Again, the Mode Effect Work Group was unable to detect a significant

questionnaire effect on measurement of the employment-to-population ratios for either

men or women. However, it is suspected that the lower estimate of temporarily absent

from a job in the Parallel Survey is at least partially attributable to the elimination of the

initial labor force question in the CPS, the splitting of the temporarily absent layoff

question into two direct questions, and the restructuring and rewording embodied in the

reasons for absences question. Given that the estimated number of males identified as "at

work" was virtually identical in the two surveys, the smaller number identified as

temporarily absent in the Parallel Survey translates into a smaller employment-topopulation ratio for men.

Unemployment to Employment Transitions

On an annual average basis, the Parallel Survey measured relatively higher

unemployment rates than the CPS for the entire population, women, adult women,

teenagers, and older workers; especially during the summer months. A natural question

to ask is: Where did these additional unemployed individuals go? Did they find

employment or did they stop looking for work and drop out of the labor market?

Comparisons of the measurements of unemployment and employment between the two

surveys provide some interesting insights into these transitions, but also present some

puzzles.

The Parallel Survey did have significantly higher annual average employment-topopulation ratio for women and adult women. These findings indicate that the Parallel

Survey is measuring more labor market activity among women in general and suggests

that at least some of the additional unemployed women measured in the Parallel Survey

are becoming employed. In addition, examination of women's 3-month moving averages
42

indicated the months that had the largest relative differences in unemployment rates were

followed by periods in which the relative difference in the percentage of women "at work

and thus women's employment was largest24 These patterns suggest that at least some of

the additional unemployed women being measured in the Parallel Survey during the

summer months were subsequently becoming employed and probably were not dropping

out of the labor market subsequent to their search for employment. The paradox is that,

among women, the largest relative differences between surveys in the unemployment

rates occurred during the summer months, but the smallest relative differences in

women's employment-to-population ratios were also in the summer. This may be

partially attributable to the effect of the smaller estimated number of women who were

temporarily absent from a job in the Parallel Survey compared to the CPS, especially

during the summer months.

The employment-to-population ratios were significantly higher in the Parallel Survey for

individuals 65 and older during the late spring and summer. Individuals 65 and older

also had significantly higher unemployment rates in the Parallel Survey during the first 3

quarters of 1993. The higher unemployment rate in combination with the significantly

higher employment-to-population ratios during the late spring and summer is consistent

with measuring more older workers who subsequently find jobs in the Parallel Survey.

However, it is also consistent with, at any point in time, measuring a larger set of

workers who are unemployed, and a different, but also larger set of older workers who

are employed. The dramatic narrowing of the difference in the unemployment rates and

the employment-to-population ratios in the fall is indicative of measuring about the same

amount of labor market activity among older workers in both surveys during the fall.

Teenagers did not display a consistent pattern of transitions. Despite the fact that the

Parallel Survey measured more unemployment among 16- to 19-year olds, especially

during the summer months. At no point in time was the Parallel Survey's estimated

 

24

1993 3-MONTH MOVING AVERAGE ESTIMATES OF

THE NUMBER OF WOMEN "AT WORK"

(in thousands)

Parallel Survey CPS Percentage Difference

Jan-Mar 52,575 51,551 1.99%

Feb-Apr 52,572 51,390 2.25%

Mar-May 52,612 51,675 1.81%

Apr-Jun 52,521 51,399 2.18%

May-Jul 51,504 50,510 1.97%

Jun-Aug 50,447 49,132 2.68%

Jul-Sep 50,575 49,478 2.22%

Aug-Oct 51,874 50,973 1.77%

Sep-Nov 53,368 52,855 0.97%

Oct-Dec 53,496 53,647 -0.28%
43

employment-to-population ratios significantly higher than the CPS estimates.

Furthermore, since the estimated number of teenagers who were temporarily absent from

a job was larger in the Parallel Survey than in the CPS, differences in teenagers

employment-to-population ratios between surveys cannot be attributed to differences in

the teenagers estimated to be temporarily absent from jobs. Part of the apparent

discrepancy between differences in teenagers employment-to-population ratios in the two

surveys and differences in their unemployment rates may be explained by the fact that

small changes in the number of unemployed affect the unemployment rates relatively

more than small changes in employment affect the employment-to-population ratio.

However, the pattern observed for teenagers suggest that some of the additional

unemployed teenagers that were measured in the Parallel Survey were not successful in

obtaining employment.

To truly explore transitions between unemployment and employment in the two surveys

the transitions of individuals will have to be analyzed. Statistical testing and modeling of

these "flows" will be conducted later.
44

IV. Labor Force Participation Rate

A. Comparison of the Total Labor Force Participation Rates

The percentage of the population that is estimated to be either employed or unemployed

is known as the labor force participation rate. Table 2.14 contains annual, quarterly, and

3-month moving average estimates of the labor force participation rates in the CPS and

Parallel Surveys. Graph 2.14 plots the relative ratio of the estimated labor force

participation rates in the two surveys.

TABLE 2.14

LABOR FORCE PARTICIPATION RATES

OF THE CIVILIAN POPULATION AGE 16 AND OLDER

Parallel Survey CPS Difference P-Value

1993 Annual

Average

Jan.-Dec. 66.63 66.19 0.45* 0.03

1993 Quarterly

Averages

Jan. - Mar 66.19 65.59 0.60* 0.03

Apr. - June 66.78 66.30 0.48* 0.07

July - Sep. 66.98 66.68 0.30 0.25

Oct. - Dec. 66.57 66.17 0.39 0.14

1993 3-Month

Moving Averages

Jan. - Mar 66.19 65.59 0.60* 0.03

Feb. - Apr. 66.18 65.61 0.57* 0.03

Mar - May 66.30 65.81 0.49* 0.07

Apr. - June 66.78 66.30 0.48* 0.07

May - July 67.25 66.90 0.35 0.18

June - Aug. 67.44 67.09 0.35 0.19

July - Sep. 66.98 66.68 0.30 0.25

Aug. - Oct. 66.62 66.32 0.31 0.24

Sept. - Nov. 66.53 66.12 0.41 0.12

Oct. - Dec. 66.57 66.17 0.39 0.14

 GRAPH 2.14
45

Relative Ratios of 3-Month Moving Average Labor Force Participation

Rates in the Parallel Survey compared to the CPS, 1993

Ratio

(PS/CPS)

1.003

1.005

1.007

1.009

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Relative Ratios

Examination of the data in Table 2.14 show that the annual labor force participation rate

was estimated to be significantly larger in the Parallel Survey than in the CPS. Further

examination also indicates that the difference in the labor force participation rates

between the two surveys was largest during the first half of the year. Only in the first

two quarters and the first four 3-month moving averages were labor force participation

rates significantly higher in the Parallel Survey than in the CPS. The decline in the

difference in the estimated rates between the two surveys, especially during the summer,

can be seen very dramatically in graph 2.14.

The finding that estimated labor force participation rates were only significantly different

between surveys during the first half of 1993, combined with the observation that the

estimated differences declined during the summer months suggest that changes in

employment had more effect on the labor force participation rates than did changes in

unemployment. Additional insights into the differences in the labor force participation

rates and the effect of differences in employment and unemployment on these differences

can be obtained by examining labor force participation rates for major demographic

groups.

B. Comparisons for Specific Demographic Groups

This section contains estimates of differences between surveys in labor force

participation rates for major demographic groups. Differences by gender are examined

first, followed by differences for various age groups. The relevant data are included in

each subsection. A single comprehensive table of the estimated labor force participation

rates by demographic groups is provided in appendix D.

Labor Force Participation Rates for Men and Women
46

Table 2.15 contains estimated annual average, quarterly, and 3-month moving average

labor force participation rates for men and women. Graph 2.14 plots the estimated 3-

month moving average labor force participation rates for men in the two surveys, and

graph 2.15 plots, over time, the relative ratio between the two surveys of the 3-month

moving average estimates. The same plots for women are presented in graph 2.16 and

2.17.

TABLE 2.15

LABOR FORCE PARTICIPATION RATES FOR MEN AND WOMEN

(AS A PERCENTAGE OF THE CIVILIAN POPULATION AGE 16 AND OLDER

Men Women

Parallel CPS Difference Parallel CPS Difference

1993 Annual

Average

Jan.-Dec. 74.82 75.21 -0.38* 59.11 57.91 1.21*

1993 Quarterly

Averages

Jan.-Mar 73.87 74.63 -0.77* 59.15 57.30 1.86*

Apr. - Jun. 74.95 75.53 -0.57* 59.28 57.83 1.46*

July - Sep. 75.65 75.99 -0.34 59.03 58.14 0.89*

Oct. - Dec. 74.82 74.68 0.14 58.99 58.36 1.72*

1993 3-Month

Moving Averages

Jan. - Mar 73.87 74.63 -0.77* 59.15 57.30 1.86*

Feb. - Apr. 73.90 74.72 -0.82* 59.11 57.25 1.86*

Mar - May 74.22 74.95 -0.72* 59.03 57.42 1.60*

Apr. - June 74.95 75.53 -0.57* 59.28 57.83 1.46*

May - July 75.80 76.26 -0.46* 59.41 58.31 1.09*

June - Aug. 76.06 76.56 -0.50* 59.52 58.40 1.12*

July - Sep. 75.65 75.99 -0.34 59.03 58.14 0.89*

Aug. - Oct. 75.04 75.34 -0.30 58.90 58.03 0.87*

Sept. - Nov. 74.78 74.80 -0.01 58.95 58.15 0.80*

Oct. - Dec. 74.82 74.68 0.14 58.99 58.36 1.72*
47

 GRAPH 2.14

3-Month Moving Average Labor Force Particapation Rates for Men, 1993

Rate

73.5

74

74.5

75

75.5

76

76.5

77

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Parallel Survey

CPS

 GRAPH 2.15

Relative Ratios Between Surveys 

 in Men's 3-Month Moving Average 

Labor Force Participation Rates, 1993

Ratio

(PS/CPS)

0.985

0.99

0.995

1

1.005

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.
48

 GRAPH 2.16

3-Month Moving Average Labor Force Particapation Rates for Women, 1993

Rate

57

57.5

58

58.5

59

59.5

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Parallel Survey

CPS

 GRAPH 2.17

Relative Ratios Between Surveys 

 in Women's 3-Month Moving Average 

Labor Force Participation Rates, 1993

Ratio

(PS/CPS)

1

1.008

1.016

1.024

1.032

Jan.-

Mar.

Feb.-

Apr.

Mar.-

May

Apr.-

Jun.

MayJul.Jun.-

Aug.

Jul.-

Sep.

Aug.-

Oct.

Sep.-

Nov.

Oct.-

Dec.

Examination of the data the annual average data in Table 2.15 establishes that the

significantly higher labor force participation rate estimated for the entire labor force hid

differences by gender. Men actually were estimated to have a significantly lower annual

labor force participation rate in the Parallel Survey than in the CPS, while women were

estimated to have a significantly higher labor force participation rate in the Parallel

Survey. Statistical testing of the relative changes in the annual labor force participation

rates between the two surveys for men and women reveals that the relative changes are

different from each other. This suggests that the increase seen for the entire population

was attributable to women.

Examination of the plots of the relative differences in the labor force participation rates

for men and women suggest that the shape of the plot over time for the entire population

was due to a combination of the changes for men and women. The general downward
49

trend for the entire population is probably due to the changes that occurred for women,

because the relative ratios generally increased for men after the second 3-month moving

average. On the other hand, the increase seen close to the end of the year for the entire

population , is probably attributable to men, because the relative difference for women

generally decreased throughout the year.

Labor Force Participation Rates for Specific Age Groups

Table 2.17 contains estimates of the annual average labor force participation rates for all

adults, adult men, adult women, and teenagers. The estimates for adults are further

subdivided by age.

TABLE 2.17

1993 AVERAGE LABOR FORCE PARTICIPATION RATES

FOR SPECIFIC AGE GROUPS

Parallel

Survey

CPS Difference P-value

Adults 67.57 67.26 0.31 0.17

 Adult Men 76.41 76.92 -0.51* 0.04

 Adult Women 59.52 58.46 1.05* 0.00

Teenagers 54.01 51.62 2.38* 0.00

Age (in years)

 20-24 77.69 77.09 0.60 0.69

 25-34 83.65 83.44 0.21 0.83

 35-44 85.21 84.96 0.25 0.80

 45-54 81.61 81.61 0.00 1.00

 55-64 55.87 56.41 -0.54 0.65

 65 and over 12.26 11.36 0.91* 0.05

The estimates in Table 2.17 indicate that both teenagers and those 65 and older had

significantly higher labor force participation rates in the Parallel Survey than in the CPS.
50

APPENDIX A
51

APPENDIX B

TABLE B.1

1993 AVERAGE UNEMPLOYMENT RATES FOR SPECIFIC DEMOGRAPHIC GROUPS

(UNEMPLOYED AS A PERCENTAGE OF THE LABOR FORCE AGE 16 AND OLDER)

Parallel

Survey

CPS Difference P-value

Total 7.26 6.80 0.45* 0.00

 Men 7.36 7.08 0.28 0.11

 Women 7.14 6.48 0.66* 0.00

Whites 6.30 5.96 0.34* 0.00

 Men 6.45 6.23 0.22 0.19

 Women 6.12 5.62 0.50* 0.00

Blacks 14.28 12.96 1.31* 0.01

 Men 14.86 13.89 0.97 0.22

 Women 13.71 12.05 1.66* 0.03

Other Races 8.90 8.19 0.71 0.28

 Men 8.69 8.61 0.08 0.93

 Women 9.14 7.68 1.46* 0.04

Hispanic 11.76 10.59 1.17* 0.03

 Men 10.35 10.44 -0.10 0.88

 Women 13.83 10.81 3.02* 0.00

Age

16-19 20.61 19.03 1.58* 0.05

20 and over 6.47 6.11 0.36* 0.01

 20-24 10.74 10.46 0.29 0.54

 25-34 7.25 6.83 0.43* 0.09

 35-44 5.66 5.45 0.21 0.36

 45-54 5.04 4.72 0.32 0.22

 55-64 4.95 4.63 0.32 0.38

 65 and over 4.72 3.10 1.62* 0.01

Adult Men 6.58 6.35 0.23 0.18

Adult Women 6.34 5.83 0.50* 0.00
52

TABLE B.2

1993 AVERAGE NUMBER OF UNEMPLOYED WITHIN DEMOGRAPHIC GROUPS

(number in thousands)

Parallel Survey CPS Difference

Total 9,359 8,714 645

 Men 5,100 4,928 172

 Women 4,259 3,785 474

Whites 6,942 6,516 426

 Men 3,861 3,747 114

 Women 3,081 2,769 312

Blacks 1,985 1,809 176

 Men 1,011 959 52

 Women 974 850 124

Other Races 431 388 43

 Men 228 222 6

 Women 203 166 37

Hispanic 1,254 1100 154

 Men 656 653 3

 Women 598 446 152

Age

 16-19 1,485 1,302 183

 20 and over 7,874 7,411 463

 20-24 1,472 1,417 55

 25-34 2,511 2,354 157

 35-44 1,940 1,868 72

 45-54 1,190 1,112 78

 55-64 581 550 31

 65 and over 180 110 70

Adult Men 4,316 4,193 123

Adult Women 3,559 3,218 341
53

APPENDIX C

Presented below are calculations to determine whether the observed differences between

the Parallel Survey and the CPS for major demographic groups were different from each

other. These calculations are based on whether the relative change observed for a

specific demographic group are different from each other, rather than on whether the

level of differences between the surveys are significant. In other words, a test was

performed to determine whether the ten percent relative difference in the unemployment

rate for women between the Parallel Survey and the CPS was statistically different from

the 4 percent relative difference for men. Tests to determine if the level of the

differences for various demographic groups (e.g., is the .66 percentage point difference

between the Parallel Survey and the CPS for women was different from the .28

percentage point difference observed for men.) were statistically different from each

other are available upon request. An example of the formula used for the test statistics

presented is:

x

Y

x

Y

x

Y

x

Y

PS WOMEN S UNRATE

CPS WOMEN S UNRATE

PS MEN S UNRATE

CPS MEN S UNRATE

PS WOMEN S UNRATE

CPS WOMEN S UNRATE

PS MEN S UNRATE

CPS MEN S UNRATE

'

'

'

'

'

'

'

'

var var

−

F

H

G I

K

J − F

H

G I

K

J

L

N

M

M

O

Q

P

P

where var

x var var

y

x

y

x

x

y

y

F

H

G I

K

J = F

H

G I

K

J +

L

N

M O

Q

P

2

2 2

a f a f
54

Test Statistics to Determine if Relative Group Differences in Unemployment Rates

are Statistically Different From Each Other

t-statistic P-value

Men vs Women 1.71* 0.09

Whites vs Blacks 0.98 0.34

Whites vs Other Race 0.35 0.73

Other Race vs Blacks 0.17 0.86

Whites vs Hispanics 0.97 0.32

White Men vs Black Men 0.54 0.58

White Men vs Other Race Men 0.24 0.80

Black Men vs Other Race Men 0.50 0.62

White Men vs Hispanic Men 0.66 0.51

White Women vs Black Women 0.72 0.48

White Wm vs Other Race Wm 1.01 0.31

Black Wm vs Other Race Wm 0.45 0.66

White Women vs Hispanic Wm 2.58 0.01

Black Women vs Hispanic Wm 0.64 0.53

65+ vs Total Population 2.10* 0.04

Teenagers vs Adults 0.50 0.60

Test Statistics to Determine if Relative Group Differences in Employment-to-Population

Ratios are Statistically Different From Each Other

t-statistic P-value

Men vs Women 3.42* 0.00

Whites vs Blacks 1.17 0.25

Whites vs Other Race 0.32 0.74

Other Race vs Blacks 0.86 0.40

Whites vs Hispanics 0.55 0.59

White Men vs Black Men 1.27 0.22

White Men vs Other Race Men 0.66 0.51

Black Men vs Other Race Men 1.04 0.29

White Men vs Hispanic Men 0.81 0.42

White Women vs Black Women 1.33 0.19

White Wm vs Other Race Wm 0.15 0.88

Black Wm vs Other Race Wm 0.48 0.62

White Women vs Hispanic Wm 0.12 0.91

Black Women vs Hispanic Wm 0.64 0.53

65+ vs Total Population 1.28 0.20

Teenagers vs Adults 1.39 0.17
55

APPENDIX D

TABLE D.1

1993 AVERAGE EMPLOYMENT TO POPULATION RATIOS FOR SPECIFIC DEMOGRAPHIC GROUPS

(EMPLOYED AS A PERCENTAGE OF CIVILIAN POPULATION AGE 16 AND OLDER)

Parallel Survey CPS Difference P-Value

Total 61.80 61.68 0.11 0.61

 Men 69.32 69.88 -0.57* 0.02

 Women 54.90 54.16 0.74* 0.00

White 63.00 62.77 0.23 0.34

 Men 70.83 71.36 -0.53* 0.05

 Women 55.70 54.76 0.94* 0.00

Black 53.40 54.40 -1.01 0.25

 Men 57.49 59.00 -1.52* 0.09

 Women 50.03 50.62 -0.59 0.60

Other Races 60.50 59.60 0.90 0.67

 Men 69.22 67.93 1.28 0.64

 Women 52.63 52.09 0.55 0.82

Hispanic 59.74 58.94 0.80 0.44

 Men 72.64 71.61 1.03 0.59

 Women 47.01 46.43 0.58 0.74

Age

16-19 42.88 41.80 1.08 0.18

20 and over 63.20 63.15 0.05 0.84

 20-24 69.34 69.03 0.31 0.83

 25-34 77.58 77.74 -0.16 0.86

 35-44 80.39 80.33 0.06 0.95

 45-54 77.50 77.76 -0.26 0.82

 55-64 53.10 53.80 -0.70 0.55

 65 and over 11.68 11.01 0.68 0.14

Adult Men 71.38 72.04 -0.65* 0.01

Adult Women 55.75 55.05 0.69* 0.03
56

TABLE D.2

1993 AVERAGE NUMBER OF EMPLOYED WITHIN DEMOGRAPHIC GROUPS

(number in thousands)

Parallel Survey CPS Difference

Total 119,606 119,389 217

 Men 64,200 64,727 -527

 Women 55,406 54,662 744

Whites 103,267 102,891 376

 Men 56,011 56,429 -418

 Women 47,256 46,461 795

Blacks 11,923 12,148 -225

 Men 5,793 5,946 -153

 Women 6,129 6,201 -72

Other Races 4,416 4,351 65

 Men 2,396 2,352 44

 Women 2,020 1,999 21

Hispanic 9,412 9,285 127

 Men 5,685 5,604 81

 Women 3,727 3,681 46

Age

 16-19 5,719 5,540 179

 20 and over 113,887 113,849 38

 20-24 12,233 12,137 96

 25-34 32,099 32,119 -20

 35-44 32,347 32,406 -59

 45-54 22,431 22,444 -13

 55-64 11,154 11,313 -159

 65 and over 3,623 3,430 193

Adult Men 61,283 61,884 -601

Adult Women 52,604 51,966 638
57

APPENDIX E

1993 LABOR FORCE PARTICIPATION RATES FOR SPECIFIC DEMOGRAPHIC GROUPS

(AS A PERCENTAGE OF CIVILIAN POPULATION AGE 16 AND OLDER)

Parallel Survey CPS Difference P-Value

Total 66.63 66.19 0.45* 0.03

 Men 74.82 75.21 -0.38* 0.06

 Women 59.11 57.91 1.21* 0.00

White 67.23 66.74 0.49* 0.03

 Men 75.71 76.10 -0.39 0.13

 Women 59.33 58.03 1.31* 0.00

Black 62.29 62.51 -0.22 0.81

 Men 67.52 68.52 -1.00 0.25

 Women 57.98 57.56 0.43 0.71

Other Races 66.41 64.92 1.49 0.50

 Men 75.80 74.34 1.47 0.62

 Women 57.93 56.42 1.51 0.57

Hispanic 67.71 65.92 1.78* 0.06

 Men 81.03 79.96 1.06 0.57

 Women 54.56 52.06 2.49 0.17

Age

 16-19 54.01 51.62 2.38* 0.00

 20 and over 67.57 67.26 0.31 0.17

 20-24 77.69 77.09 0.60 0.69

 25-34 83.65 83.44 0.21 0.83

 35-44 85.21 84.96 0.25 0.80

 45-54 81.61 81.61 0.00 1.00

 55-64 55.87 56.41 -0.54 0.65

 65 and over 12.26 11.36 0.91* 0.05

Adult Men 76.41 76.92 -0.51* 0.04

Adult Women 59.52 58.46 1.05* 0.00
58

REFERENCES

Cahoon, Lawrence, and Kostanich, Donna. (1994). Effects of Design Differences

Between the Parallel Survey and the Redesigned Current Population Survey, CPS Bridge

Team Technical Report 3.

McKay, Ruth. (1993). Observation of Hispanic Interviews in the CPS. Unpublished

Bureau of Labor Statistics memorandum.

Miller, Stephen. (1994). What Would the Unemployment Rate Have Been Had the

Redesign Current Population Survey Been in Place from September 1992 to December

1993?: A Measurement Error Analysis, CPS Bridge Team Technical Report 1.

Palmisano, Mark. (1989). "Respondents Understanding of Key Labor Force Concepts

Used in the CPS," in Proceedings of the Section on Survey Research Methods,

Alexandria, VA: American Statistical Association.

Rothgeb, Jennifer. (1982). Summary Report of July Follow-up of the Unemployed.

Unpublished Bureau of the Census memorandum.

Rothgeb, Jennifer. (1994) Revisions to the CPS Questionnaire: Effects on Data Quality,

CPS Overlap Analysis Team Technical Report 2.

Thompson, Jenny. (1994). Mode Effects Analysis of Major Labor Force Estimates, CPS

Overlap Analysis Team Technical Report 3.

U. S. Bureau of Labor Statistics and U. S. Bureau of the Census (1986), Report of the

BLS-Census Bureau Questionnaire Design Task Force.