Who Is Unemployed?

Factors Affecting

Unemployment

Among Individuals

with Doctoral

Degrees in Science

and Engineering

Division of Science Resources Studies

Directorate for Social, Behavioral and Economic Sciences

National Science Foundation NSF 97-336

An SRS Special Report
Who Is Unemployed?

Factors Affecting

Unemployment

Among Individuals

with Doctoral

Degrees in Science

and Engineering

An SRS Special Report

Carolyn F. Shettle, Principal Author

Division of Science Resources Studies

Directorate for Social, Behavioral and Economic Sciences

National Science Foundation NSF 97-336
Suggested Citation

National Science Foundation, Division of Science Resources

Studies, Who Is Unemployed? Factors Affecting Unemployment Among Individuals with Doctoral Degrees in

Science and Engineering, Special Report, NSF 97-336, by

Carolyn F. Shettle (Arlington, VA, 1997).

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ii
iii

This report was prepared by Carolyn Shettle,

Director, Doctorate Data Project, Division of Science

Resources Studies (SRS), National Science Foundation.

SRS staff members Joan Burrelli, Carlos

Kruytbosch, Rolf Lehming, Melissa Pollak, and Mark

Regets provided numerous helpful comments to various

drafts of this report, as did Catherine Gaddy, Executive

Director of the Commission on Professionals in Science

and Technology, and Daryl E. Chubin, Director of the

Division of Research, Evaluation, and Communication

within NSF’s Directorate for Education and Human

Resources. Special thanks to Kenneth M. Brown,

former Division Director of SRS, who originally

ACKNOWLEDGMENTS

suggested the topic of this report and helped with its

early development. Jeanne E. Griffith, current Division

Director of SRS, and Alan R. Tupek, Deputy Division

Director of SRS, provided overall guidance for the

latter stages of the production of this report. The report

has been greatly strengthened by the help these

individuals provided.

Editorial assistance was provided by Daniel

Gottlieb, Gottlieb Associates. Anne Houghton, Julia

Harriston, and Tanya Gore of the Publications

Management Group of SRS provided copyediting,

processing, and final composition for this report.
v

CONTENTS

ACKNOWLEDGMENTS ..................................................................................................................................... iii

KEY TERMS ........................................................................................................................................................vii

EXECUTIVE SUMMARY ....................................................................................................................................1

I. INTRODUCTION...........................................................................................................................................3

Limitations of This Study ...................................................................................................................................3

II. TRENDS IN DOCTORAL SCIENCE AND ENGINEERING UNEMPLOYMENT ......................5

Introduction ........................................................................................................................................................5

Past Trends ........................................................................................................................................................5

Future Trends .....................................................................................................................................................6

Conclusions ........................................................................................................................................................7

III.FACTORS AFFECTING UNEMPLOYMENT IN 1993 ....................................................................9

Introduction ........................................................................................................................................................9

Demographic Factors ........................................................................................................................................9

Race/Ethnicity .............................................................................................................................................9

Gender and Family Status ...........................................................................................................................9

Place of Birth ............................................................................................................................................10

Disability Status ......................................................................................................................................... 11

Age and Time Since Completion of Degree ............................................................................................. 11

Factors Relevant for Career Decisions ...........................................................................................................13

Educational Decisions ...............................................................................................................................13

Amount of Work Experience ....................................................................................................................16

Other Career Choices ...............................................................................................................................20

Conclusions ......................................................................................................................................................21

IV. CHANGES IN FACTORS AFFECTING UNEMPLOYMENT SINCE 1973 ............................23

Introduction ......................................................................................................................................................23

Demographic Factors ......................................................................................................................................23

Gender .......................................................................................................................................................23

Age ............................................................................................................................................................23

Factors Relevant to Career Decisions.............................................................................................................23

Conclusions ......................................................................................................................................................25

V. CONCLUSIONS AND FUTURE RESEARCH.....................................................................................27

Conclusions ......................................................................................................................................................27

Unemployment in the Larger Career Context .................................................................................................27

Future Research ..............................................................................................................................................28

Section Page
vi

BIBLIOGRAPHY ..................................................................................................................................................29

APPENDIX A: UNEMPLOYMENT, INVOLUNTARY PART-TIME EMPLOYMENT,

AND INVOLUNTARY OUT-OF-FIELD RATES, FOR SELECTED SUBGROUPS

WITHIN THE DOCTORAL SCIENCE AND ENGINEERING POPULATION: 1993 ......................31

APPENDIX B: ADDITIONAL INFORMATION ON FACTORS AFFECTING

UNEMPLOYMENT ..............................................................................................................................................39

Introduction ......................................................................................................................................................41

Variables Excluded from the Multivariate Analysis .........................................................................................41

Pursuit of Additional Degrees and Courses After Receipt of the Doctorate ...........................................41

Spouse’s Work Status ................................................................................................................................42

Professional Association Activities ...........................................................................................................42

Other Variables .........................................................................................................................................43

Variables Eliminated During the Multivariate Analysis for Lack of Statistical Significance ...........................43

Occupational Characteristics ....................................................................................................................43

Prior Retirement ........................................................................................................................................44

Birth in a Rural Area .................................................................................................................................44

Citizenship ..................................................................................................................................................44

Interaction Between Race/Ethnicity and Whether Born in the United States .........................................44

Other Variables in the Final Model Not Discussed in the Body of the Report ...............................................44

1988 Occupation Characteristics ..............................................................................................................44

Parental Education ....................................................................................................................................45

Interaction Between Marital Status and Race/Ethnicity ...........................................................................46

Foreign Research Experience ...................................................................................................................46

APPENDIX C: TECHNICAL NOTES

Data Used in This Report ................................................................................................................................49

The Survey of Doctorate Recipients .........................................................................................................51

Historical Data ..........................................................................................................................................51

Total Population Data ................................................................................................................................51

Trend Analysis .................................................................................................................................................51

Variable Definitions ..........................................................................................................................................52

Unemployment Rate..................................................................................................................................52

Involuntary Part-Time Rate .......................................................................................................................52

Involuntary Out-of-Field Rate ...................................................................................................................52

Occupation.................................................................................................................................................52

Variables Related to 1988 Employment and Occupational Status ............................................................52

Other Variables .........................................................................................................................................53

Standard Errors and Tests of Significance ......................................................................................................53

Standardization Methodology ...........................................................................................................................53

Section Page

CONTENTS—CONTINUED
vii

KEY TERMS

Unemployed: Either on layoff or not employed but

searching for work (during the four-week period prior

to the reference date). NOTE: Individuals who are not

working and not employed are defined as being out of

the labor force. This group includes most individuals

who are voluntarily not employed.

Labor Force: The labor force consists of unemployed

plus employed individuals.

Unemployment Rate: The percent of the labor force

that is unemployed.

Standardized Unemployment Rates: A number of

techniques can be used to estimate the effect of one

(independent) variable on another (dependent) variable,

while “controlling” for other variables. The most

straightforward technique is to construct a three-way

table. For example, the average age of women in the

doctoral labor force is less than that of men. To determine whether age and/or gender are related to the

unemployment rate, it is logical to look at unemployment rates within sex-age groups (for example, men

under age 30 compared with women under age 30, men

aged 31–35 compared with women aged 31–35, etc.).

Although cross-tabulations can be extremely helpful in

understanding how two or more independent variables

affect a single dependent variable, usefulness is limited

by the fairly large sample sizes needed to estimate

accurately subgroup unemployment rates. This becomes an especially serious problem when controlling

for more than one variable. (For example, to understand whether observed differences in unemployment

rates for individuals with disabilities can be explained

by the fact that individuals with disabilities tend to be

older than individuals without disabilities, and the fact

that the incidence of disabilities tends to be higher

among men than among women).

Instead of using cross-tabulations for control

purposes in this report, a multivariate technique known

as logistic regression analysis was used to estimate the

simultaneous effect of a large number of variables on

unemployment. The independent variables used in the

logistic regression model are: degree field; place of

employment or residence; years since receipt of Ph.D.;

age when doctorate received; years of part-time

experience; years of full-time experience; whether or

not employed in April 1988; occupation in April 1988

(for employed individuals); employment sector in April

1988 (for employed individuals); parents’ level of

education; disability status; percent involuntarily out-offield in the 1988 occupation; foreign research

experience; marital status; interaction between gender

and marital status; interaction between gender and

whether children are in the home; interaction between

gender and race/ethnicity; and interaction between

marital status and race/ethnicity.

The logistic regression model was used to estimate

the unemployment rate for a group of individuals who

exhibited the same values on all of the independent

variables except the one under consideration. For

example, the observed unemployment rate for

individuals with hearing disabilities was 3.0 percent,

compared with a rate of 1.6 percent for non-disabled

doctoral scientists and engineers; the respective

standardized rates were 2.5 percent and 1.6 percent.

Thus, factors listed above (other than whether the

person had a hearing disability) explained some but not

all of the observed difference between those with

hearing disabilities and those without disabilities.

More detailed information about the standardization

process is included in the Technical Notes. (See p. 47.)
1

The primary purpose of this report is to explore

empirically the factors affecting unemployment1 among

individuals with U.S. doctoral degrees in science and

engineering in 1993. This information is of interest to

individuals who are in—or considering entering—

science and engineering, their advisors, and those

responsible for programs serving them. The major

questions addressed are:

How high were unemployment rates for doctoral

scientists and engineers in the early 1990s?

• The 1993 unemployment rate of 1.6 percent was

the highest rate observed in the biennial Survey of

Doctorate Recipients (SDR) between 1973 and

1995. However, the April 1993 unemployment rate

for those with science and engineering doctorates

was substantially below the total population rate of

7.1 percent. The 1995 doctoral unemployment rate

of 1.5 percent was virtually unchanged from the

1993 rate, even though the unemployment rate in

the total labor force declined considerably to 5.7

percent.

How well can we predict unemployment rates in the

doctoral science and engineering population?

• According to evaluations of past forecasts of the

doctoral science and engineering job market, it is

not now possible—and may never be possible—to

forecast doctoral science and engineering

unemployment rates with sufficient accuracy to be

helpful in deciding whether or not to pursue

doctoral-level careers in science and engineering,

particularly in view of the long lead-time for

obtaining this degree.

If we can’t predict unemployment rates, why is it

worth asking who is unemployed?

• Even though it is not possible to predict total

doctoral science and engineering unemployment

rates, generalizations can be made about

unemployment in this population. For example, in

the mid-1980s, an examination of doctoral science

and engineering unemployment trends would

probably not have led to an accurate prediction of

the 1995 unemployment rate, but could have

correctly predicted that doctoral scientists and

engineers would continue to experience

unemployment rates below those of the general

population. It is reasonable to hypothesize that

there is also some stability in the relative levels of

subgroup unemployment rates over time.

Within the doctoral science and engineering

population in 1993, who was most likely to be

unemployed?

• Neither gender nor race/ethnicity had a statistically

significant relationship with unemployment, when

the other variables in this analysis were taken into

account. However, having a hearing or mobility

impairment or advanced age were associated with

relatively high unemployment.

• Marital status and having children in the home have

different effects on the unemployment status of the

two sexes. For women, being married and having

children were associated with relatively high

unemployment rates; for men they were associated

with relatively low unemployment rates.

• Education-related decisions are important

predictors of unemployment:

– Age at completing the doctorate is strongly

associated with unemployment. When

controlling for other relevant variables, the

unemployment rate ranged from 0.6 percent

for those who received doctorates before age

26 to 5.8 percent for those who received

doctorates at age 40 or older.

– Degree field is also important. In 1993,

unemployment rates ranged from 0.6 percent

for those with degrees in civil engineering to

2.5 percent for those with degrees in the

geological and environmental sciences.

• Disruptions in full-time employment subsequent to

receiving a doctorate increase significantly the

chances of unemployment:

EXECUTIVE SUMMARY

1 The definition of unemployment used in this report is the

standard Federal definition of not being employed and either being

on lay-off or having sought work within the preceding four weeks.

Individuals who are voluntarily without employment due to

retirement, illness, family responsibilities, etc. are considered to be

out of the labor force.
2

– Among those who were either unemployed or

not in the labor force in 1988, the 1993

unemployment rate was 4.1 percent, compared

to 1.5 percent for those who were employed in

April 1988. The 1993 unemployment rate for

those who had completed their doctorates

before 1988, but were not employed in that

year, was 9.6 percent—the highest

unemployment rate observed in the study.

– Unemployment decreases with the number of

years of previous full-time employment, when

other variables are controlled for. However,

prior part-time employment is associated with

above-average unemployment rates.

• Other career-related variables found to be related

to unemployment in 1993 were:

– Among those employed in 1988, employment in

the private-for-profit sector was associated

with relatively high 1993 unemployment (2.6

percent). In contrast, prior employment in

academia or the government was associated

with low unemployment rates.

– Occupation in 1988 was also a factor in

predicting 1993 unemployment. The observed

rates ranged from under 0.4 percent for

postsecondary teachers in the physical

sciences and engineering in 1988 to 2.9 percent

for chemists (excluding postsecondary

teachers). In general, those employed as

postsecondary teachers in 1988 had lower

unemployment rates than individuals in allied

fields who were not postsecondary teachers.

– Geographic location had a modest association

with unemployment in the doctoral science and

engineering population. Unemployment rates

ranged from 0.3 percent in less populated

states in the West North Central region (Iowa,

North Dakota, South Dakota, Nebraska, and

Kansas) to 2.8 percent in California in 1993.

This association remained even after

controlling for other relevant variables.

Have the factors affecting unemployment changed

over time?

• There was a notable change between 1973 and

1993 in the association between gender and

unemployment. In 1973, unemployment for men

was 0.9 percent versus 3.9 percent for women; in

1993, the rates were 1.6 and 1.8 percent,

respectively. This mirrors a similar decrease in the

gender unemployment gap in the general

population.

• Being an older member of the labor force is more

strongly associated with unemployment in 1993

than in 1973.

• Although field of degree has a modest relationship

with unemployment in both 1973 and 1993, there

is little consistency between the two years on

fields with the highest unemployment rates. This

is consistent with traditional economic theory that

indicates markets tend toward equilibrium over

time. For example, when demand for a particular

skill is high, compensation for the skill increases,

which, in turn, encourages more individuals to

acquire the scarce skill, thereby reducing or

eliminating the scarcity.

• For the other two career-related decisions

examined (sector and place of employment/

residence), there was little difference between

1973 and 1993 in either the strength of the

associations or the pattern of the unemployment

rates.

How well does the unemployment rate perform as

an indicator of career outcomes compared to other

possible indicators?

• The unemployment rate is viewed by economists

as an indicator of the health of the economy.

However, from the individual’s perspective,

unemployment is only one of several possible

desirable or undesirable career outcomes,

resulting from a combination of job opportunities,

individual choices, and luck. For example, when

individuals are unable to find suitable full-time

employment, they may decide to search for

employment that is part-time and/or inconsistent

with the level or field of their training. Because

individual choices and job opportunities are

themselves a function of many of the factors

examined in this report, it is not surprising that the

association between unemployment and the

alternate measures of labor market stress

(involuntary part-time employment and

involuntary out-of-field employment) is weak.