U.S. Census Bureau Research at the Center for Economic Studies and the Research Data Centers: 2009 19 

Additional years of microdata 

from the Annual Survey of 

Manufactures (ASM), Survey 

of Industrial Research and 

Development (SIRD), and the 

Current Population Survey are 

just a few examples of the valuable data recently recovered by 

the Center for Economic Studies 

(CES). See Text Box 4-1 for highlights of recovered data.

Historic data from over 2,500 

tapes were recovered before the 

Census Bureau’s Unisys mainframe computer was decommissioned in 2010. In the 2008 

Research Report, CES noted the 

many household and business 

files to be recovered and sought 

the help of the research community (Becker and Grim, 2009 

and Gardner, 2009). Without the 

intensive recovery effort led by 

CES during the last half of 2009, 

important information would 

have been lost forever.

Chapter 4.

RECOVERY OF HISTORICAL U.S. CENSUS BUREAU MICRODATA: 

SUCCESS TO DATE

B.K. Atrostic, Randy Becker, Todd Gardner, Cheryl Grim, and Mark Mildorf, Center for Economic Studies

Text Box 4-1.

RECOVERED DATA: HIGHLIGHTS

The economic and demographic data recovered from the Unisys will be valuable additions to the data 

already available at the Center for Economic Studies (CES) and the Research Data Centers (RDCs).

Most files will require additional work before they can be used for research purposes, and some may 

require approval by sponsoring agencies. Examples of data recovered from the Unisys include:

• Earlier years of series already available at C

· Censuses of Mining, Retail, Wholesale, and Services

· Annual Survey of Manufactures (ASM)

· Survey of Industrial Research and Development (SIRD)

· Survey of Minority-Owned Business Enterprises

· Commodity Transport Survey (now called the Commodity Flow Survey)

· Decennial Census data

 ~ Puerto Rico sample and complete count files

 ~ U.S. Possessions sample and complete count files

· Selected Current Population Survey (CPS) March Supplements

• Series not currently available at C

· Agriculture Surveys and Censuses

· Annual Survey of Oil and Gas

· Heating Fuel Survey

· Water Use Survey

· Survey of Construction

· Income Surveys Development Program

· CPS Supplements for months other than March

• New variables for series already available at C

· Census of Manufactures (CM) special inquiries data

· ASM Central Administrative Office data

· ASM and CM data flags

• Historical analysis files (see Text Box 4-

· Industrial Time Series data 

· Linked CM/SIRD data created for Zvi Griliches
20 Research at the Center for Economic Studies and the Research Data Centers: 2009 U.S. Census Bureau

nearly two decades. See Text 

Box 4-3. 

Innovative on-the-fly solutions to 

problems that hampered earlier 

data recovery efforts let CES 

surmount a series of technical, 

operational, and administrative 

challenges that each threatened to halt the recovery in 

mid-process. 

While CES led the recovery 

effort, success on this scale 

required help from many partners. The project got off the 

ground because of the strong 

support of C. Harvey Monk, 

Jr., then Associate Director 

for Economic Programs at the 

Census Bureau.

We also appreciate the support 

of the Census Bureau’s Computer 

Services Division. They granted 

us additional time to access

the Unisys machine and graciously allowed us to use their 

office facilities.

been proven for the ASM and 

SIRD. See Text Box 4-2.

The 2009 recovery effort built 

on work that had been going 

on at a much lower intensity for 

The recovered files have the 

potential to bring new data 

series to CES, extend existing 

data series at CES by a decade 

or more, and fill gaps in existing 

data. This potential has already 

The data recovery project has already borne 

fruit. Annual Survey of Manufactures (ASM) data 

dating as far back as 1954 have been recovered, 

and as many as 15 years of additional historical 

data from the Survey of Industrial Research and 

Development (SIRD) have been recovered for 

large firms.1

The oldest microdata available to researchers at 

the Center for Economic Studies (CES) and in the 

Research Data Centers (RDCs) as of December 

2009 were manufacturing data from the 1963 

Census of Manufactures (CM). Extending the 

manufacturing microdata series provides opportunities to study the evolution and behavior of 

plants and industries over longer time periods 

and more business cycles.

Industrial Time Series Data

In the 1960s, Census Bureau staff created a 

longitudinal microdata file using the ASM. 

Internally, the file was referred to as the 

Industrial Time Series (ITS). They began with a 

pilot study using data from 1954–1961. They 

selected 25 industries containing about 2,500 

establishments (Conklin, 1964).2

Text Box 4-2.

NEWLY AVAILABLE HISTORIC DATA: THE MANUFACTURING SECTOR

 

1 The recovered data have not been fully converted into 

research-ready format nor have the data gone through 

exhaustive checks for completeness.

 

2 Most of the selected industries were capital-intensive 

and many were primary metals industries. 

Continued on page 21

Occupying 336 square feet, the Unisys IX Clearpath 4400 and 6 tape 

drives were purchased by the Census Bureau in 1995.

Photo by Lauren Brenner
U.S. Census Bureau Research at the Center for Economic Studies and the Research Data Centers: 2009 21 

Research papers using the data from the pilot 

study show early evidence of the value of longitudinally linked microdata. Jordan (1965) studies the measurement of capacity utilization, and 

Schaffer (1968) looks at changes in the structure 

of manufacturing employment.

CES recovered not only the original pilot study 

data, but also what we believe to be the 1954–

1964 linked ASM data covering all manufacturing industries discussed in Kallek (1982). 

The ITS data were abandoned when a new, 

and ultimately very successful, project to link 

manufacturing data began in the early 1980s 

(Kallek, 1982). This project was led by Nancy 

Ruggles and Richard Ruggles and developed the 

Longitudinal Establishment Database, a predecessor to the manufacturing microdata available 

at CES today (Atrostic, 2009).

The ITS data were not included in the 1980s project because of anticipated difficulties in linking 

to the more recent 1972 data. Given the computing capabilities and other data sources available 

now, there is a good probability these data can 

be linked to the currently available manufacturing data at CES.3

Griliches R&D Data

In the mid-1960s, Zvi Griliches—famed Harvard 

University economist, then at the University

of Chicago—was approached by the Census 

Bureau and the National Science Foundation

to work on a project analyzing historical data

on industrial R&D.

Griliches led efforts to develop a longitudinallylinked dataset containing 1957–1965 companylevel data from the Survey of Industrial Research 

and Development (SIRD) matched to data from 

the 1958 and 1963 CM and Enterprise Statistics 

(ES). Griliches (1980) details this effort and 

discusses limitations of the data. Using these 

linked data, he found a positive relationship 

between investments in R&D and company 

productivity.

Griliches returned to the Census Bureau 

to extend his work in the early 1980s. 

Unfortunately, the data from his original project 

had been lost (Griliches, 1986).

With Census Bureau staff doing the hands-on 

data work, Griliches designed a new dataset. 

The new dataset contained 1957–1977 firmlevel data from the SIRD matched to data from 

the 1962, 1967, and 1977 ES and data from the 

1967 and 1972 CM. The sample was limited to 

certainty companies from the 1972 SIRD and 

contains approximately 1,100 companies.

Griliches highlights three findings in his 1986 

paper: (1) investments in R&D make a positive 

contribution to productivity growth; (2) basic 

research is a more important contributor to 

productivity than other types of R&D; and (3) 

privately-financed R&D expenditures appear 

to be more effective at the company-level than 

federally-financed R&D expenditures.

The data underlying the findings in Griliches 

(1986) were recently recovered from the Unisys 

machine as part of the historical data recovery project.4 CES currently has data from the 

SIRD going back to 1972. The addition of the 

Griliches sample extends our historical information for many large R&D companies back

to 1957. 

While the Griliches sample is limited to large 

companies and key SIRD variables (e.g., total 

R&D expenditures, number of scientists and 

engineers), up to 15 additional years of data will 

now be available for many large R&D companies. The recovered data have been converted 

into SAS datasets. Foster and Grim (2010) use 

these newly recovered data to extend the period 

covered in their analysis of research and development back to the 1950s.

4 The recovered data do not include the 1977 ES data.

Text Box 4-2.—Con.

 

3 See Becker and Grim (2009) for more information 

on other sources of available historical manufacturing 

microdata.
22 Research at the Center for Economic Studies and the Research Data Centers: 2009 U.S. Census Bureau

Before 1998: Microdata recovered from Unisys 

computers were the source of major CES products, such as the original Longitudinal Research 

Database (LRD) (Atrostic, 2009 and McGuckin 

and Pascoe, 1988).

1998–2007:

Recovering files 

became harder. 

Staff with the 

necessary skills 

and institutional memory 

retired. The 

Unisys machine 

became 

increasingly 

fragile, prone 

to crashes, 

and difficult to 

bring back on 

line. 

Important data 

from several 

censuses and 

surveys were 

nevertheless 

retrieved and 

some made 

available for research. Among the data recovered were microdata for the 1960–1990 decennial censuses (Gardner, 2009); the 1955, 1956, 

and 1965–1971 Annual Survey of Manufactures 

(Becker and Grim, 2009); and the 1973–1978 

Pollution Abatement Costs and Expenditures 

survey (Becker, 2007).

But moving the thousands of files remaining on 

the Unisys remained a low priority. CES would 

need to identify which of those files existed 

nowhere else, and only one person at CES had 

extensive experience on 1100/2200 Unisys 

mainframes.

2008–2009: When the Census Bureau 

announced the Unisys machine would be 

decommissioned in late 2008, CES was able to 

delay the decommissioning.

2009: CES reached out to the research community. The research potential of microdata remaining on the Unisys were described in a presentation by B.K. 

Atrostic at the 

National Bureau 

of Economic 

Research 

Productivity 

Program meeting in March 

2009, and articles by Becker 

and Grim, 

and Gardner 

in the 2008 

CES Research 

Report. CES 

actively solicited the views 

of our Research 

Data Center 

partners and, 

through them, 

the broader 

research community. Strong 

positive feedback and concrete support gave 

CES efforts new life.

Text Box 4-3.

RECOVERING HISTORICAL MICRODATA: A LONG HISTORY

Photo by Lauren Brenner

One of many drawers full of paper data storage 

register files, which contain vital information for 

the recovery of data files stored on the Unisys.

Over a decade ago, then-CES researcher, Al Nucci (1998) 

wrote of the significant technical and institutional challenges in moving historical microdata to modern computing systems: 

“In principle, it ought to be a relatively straightforward 

exercise to obtain these data (i.e., a copy from archival 

tapes). This is not the case. The Census Bureau’s legacy 

mainframe is a nonstandard UNISYS (a descendant of the 

earlier UNIVAC computers). Further, the Census Bureau 

enhanced the capabilities of these computers with a proprietary file system. Hence the migration of data from earlier 

years not only has the more traditional problem of missing 

or incomplete file documentation and deteriorating tape 

files but requires the use of specialized software, often 

specially written for each file. 

Further, the skills required for these tasks are no longer 

common at the [Census] Bureau and becoming increasingly rare as time progresses, in addition to the continuing 

diminution of Census Bureau institutional memory on the 

contents of earlier files and at their creation.”
U.S. Census Bureau Research at the Center for Economic Studies and the Research Data Centers: 2009 23 

Center for Economic Studies 

B.K. Atrostic

Randy Becker 

Jason Chancellor

Joshua Coates (intern)

Henry Cross (intern)

Todd Gardner

Cheryl Grim

Mark Mildorf

Rose Taylor

Ya Jiun Tsai

Demographic Surveys Division

Zelda McBride

Sue Peters

Economic Statistical Methods and

 Programming Division

Connie Christensen

Stephen Jarvis

Keith Paterno

Robert Penrod

Daniel Vacca

Population Division 

Marie Pees

Research Data Center Partner Support

Baruch College, CUNY System 

University of California, Berkeley 

University of Michigan Interuniversity 

 Consortium for Political and Social Research

University of Minnesota Population Center

Text Box 4-4.

THE DATA RECOVERY TEAM 

Photo by Lauren Brenner

Center for Economic Studies (CES) Assistant 

Division Chief for Research Support, Mark 

Mildorf, with the Unisys in January 2010. As 

the only CES member of the data recovery 

team with prior experience on a Unisys, Mark 

led the charge to download data.

CES assembled team members from a number of professions and divisions across the 

Census Bureau. Partners from 

the Research Data Center (RDC) 

system and the broader research 

community also joined the data 

recovery team. See Text Box 4-4. 

Recovery is only the first step in 

creating usable research microdata files. CES programmers are 

working to develop processes 

that should greatly streamline 

the last steps of converting the 

data from legacy formats and 

character sets to more readily 

accessible formats, such as ASCII 

or SAS datasets. After the conversion is completed, substantial 

work will remain to assess the 

data and make them consistent 

with data already at CES. 

Decommissioning the Unisys 

closed a long and significant 

chapter in Census Bureau 

computing history. Some of 

the recovered files were likely 

initially processed on the Census 

Bureau’s UNIVAC I computer, first 

used by the Census Bureau in 

1951. See Text Box 4-5.

DATA RECOVERY PROCESS 

The data recovery team overcame significant challenges to 

recover data from the Unisys:

• Identifying data to be recovered

• Moving data from the Unisys

• Keeping the Unisys running

Identifying Data to be 

Recovered 

The first challenge was to create 

a list of “rescue worthy” data 

files on the Unisys. 

Information about data stored 

on the Unisys, such as data 

storage forms, record layouts, 

and lists of computer tapes for 

each “data storage submission” 

are stored in a paper file called a 

“register.” A data storage register may represent an entire 

economic census with scores of 

tapes holding several different 

files and millions of records, or 

part of a survey with a single 

tape holding a single file with 

only a few hundred records.
24 Research at the Center for Economic Studies and the Research Data Centers: 2009 U.S. Census Bureau

in late October 2009 to emphasize transferring data from the 

Unisys as quickly as possible. 

The creation of research-ready 

SAS datasets was deferred. 

This change, together with 

process improvements and 

increased staffing, led to a dramatic improvement in the flow 

of data from the Unisys. In the 

6 months prior to the change 

in processing, the data recovery team moved economic data 

from approximately 20 registers 

from the Unisys. In the 4 months 

Moving data from the Unisys 

was a complicated process with 

many technical challenges. See 

Text Box 4-6.

The data had to be converted 

from a variety of formats to

a format that could be copied 

from the Unisys and read on a 

modern computer. Initially, the 

unstructured data were read in 

variable-by-variable and loaded 

into SAS datasets. This procedure 

proved to be painstakingly slow.

The data recovery team made a 

major change to this procedure 

CES researchers examined over 

2,000 registers. Consulting with 

other subject-matter experts

as needed, they set priorities

for recovery and created electronic scans of hundreds of 

important registers. 

Moving Data From the 

Unisys

After the data to be recovered 

were identified, much work 

remained. The next step was to 

move data from the Unisys to a 

modern computer system.

Decommissioning the Census Bureau’s Unisys 

Clearpath 4400 Mainframe will end a thread of 

computer usage reaching back to the 1950s. 

The Census Bureau purchased UNIVAC I, serial 

number 001, in 1951. It was the first commercial electronic general-purpose data processing 

computer. 

However, the lineage of the Unisys Clearpath is 

better traced back to the UNIVAC 1100 series of 

mainframe, specifically the UNIVAC 1105 and 

1107 models. 

In 1958, the Census Bureau acquired the first 

two UNIVAC 1105 computers ever sold. In 1963, 

the Census Bureau purchased two UNIVAC 1107 

computers.1

Since then, the Census Bureau has had one or 

more 1100 or 2200 series mainframes in near 

continual operation.

The Unisys Clearpath 4400 is in the same family line as the UNIVAC 1107, sharing hardware 

characteristics (such as the 36 bit word) and 

using the same family of operating systems. 

The Census Bureau’s UNIVAC I was retired in 

1964. The UNIVAC 1105s were retired in 1967, 

and the UNIVAC 1107s were replaced in 1971. 

The Unisys Clearpath 4400 is the last Unisys 

mainframe in operation at the Census Bureau. 

The Unisys Corporation discontinued support of 

the Clearpath as of December 31, 2009, and it 

was decommissioned in 2010.

Text Box 4-5.

THE UNISYS: END OF COMPUTING ERA THAT BEGAN WITH UNIVAC I

Photo by U.S. Census Bureau, Public Information Office

Built by Remington-Rand, using more than 5,600 

computer vacuum tubes; 18,000 crystal diodes; 

and 300 relays, UNIVAC was the world’s first 

commercial computer. 

 

1 For more information, see the CNN news article “50th 

Anniversary of the UNIVAC I,” available at <archives

.cnn.com/2001/TECH/industry/06/14/computing

.anniversary/>. 
U.S. Census Bureau Research at the Center for Economic Studies and the Research Data Centers: 2009 25 

Listed below is a small subset of the technical 

issues that made the data recovery effort such a 

challenging exercise. 

1. The Unisys operating environment. Expertise 

with the Unisys 1100/2200 series is now 

rare at the Census Bureau. Most of the data 

recovery work was done by people who 

had never previously logged on to a Unisys. 

Of the Center for Economic Studies staff 

involved with the recovery effort, only one 

had prior experience on a Unisys, and that 

experience ended in 1982.

2. Legacy character sets. Although some of 

the data recovered were in the ASCII character set, the vast majority of the data were 

in the less familiar FIELDATA character set. 

Developed in the 1950s by the Department 

of Defense, the FIELDATA character set was 

only used widely in commercial computing 

on the Unisys 1100/2200 series. EBCDIC 

data and data in the Excess-3 character set, 

a character set not widely used since the 

1960s, were also recovered.

3. Completely unstructured data. All of the data 

recovered were stored in files that did not 

enforce any data structure. To enable users 

to properly interpret the data, hardcopy 

record layouts—road maps of the data—were 

prepared when these files were initially 

created. In many cases, the record layouts 

were lost, requiring the data recovery team 

to develop and implement new methods to 

move the data off of the Unisys.

4. Unique record and file formats. Much of the 

data were stored in CENsus Input Output 

(CENIO) files. CENIO is a unique Census 

Bureau-developed file structure. Data were 

also retrieved from “Algol Direct Access 

files” and a “save file” from a System 2000 

database.

Text Box 4-6.

TECHNICAL CHALLENGES TO THE DATA RECOVERY EFFORT

following the change, the data 

recovery team moved data from 

over 490 economic registers.

Moving data files from the Unisys 

was a major production effort. 

Over 2,500 tapes were processed. The resulting 7,000-plus 

data files were then copied from 

the Unisys to Linux computers.

Keeping the Unisys Running

No account of the data recovery 

effort would be complete without noting the vital role played 

by Rose Taylor, a retired Census 

Bureau employee with over

25 years of experience with

the Unisys. 

Brought back as a contractor, 

Taylor was essential in keep- Rose Taylor, a retired Census employee and key member of the data 

recovery team, with the Unisys in January 2010.

Photo by Lauren Brenner
26 Research at the Center for Economic Studies and the Research Data Centers: 2009 U.S. Census Bureau

from the Unisys. However, as of 

March 2010, relatively little of 

the data from the recovered registers has been converted into 

SAS datasets. Further processing is required to convert the 

remainder of the recovered data 

to modern formats. 

Record layouts are not available 

for some data files. These cases 

will require additional analysis 

to reconstruct the record layout. 

File conversion is potentially 

a painstaking process, but the 

end result should be to make 

detailed data available to analyze important economic and 

social issues.

Researchers interested in partnering with CES to develop these 

data should contact the authors 

or send an e-mail to <CES.Data

.Recovery.List@census.gov>. 

REFERENCES

Atrostic, B.K. 2009. “The Center 

for Economic Studies 

1982–2007: A Brief History.” 

Center for Economic 

Studies Discussion Paper 

CES-WP-09-35.

Becker, Randy. 2007. “New 

Developments With the 

Pollution Abatement Costs 

and Expenditures (PACE) 

Survey.” In Research at the 

Center for Economic Studies 

and the Research Data 

Centers: 2006. <www.ces

.census.gov>

Becker, Randy and Cheryl Grim. 

2009. “Recovering Historical 

Manufacturing Microdata.” 

In 2008 Research Report: 

Center for Economic Studies 

and Research Data Centers. 

<www.ces.census.gov>

Conklin, Mawell R. 1964. “Time 

Series for Individual Plants 

from the Annual Survey of 

Manufactures and Related 

Data.” Presented at a Joint 

Session of the American 

Economic Association and 

the American Statistical 

Association on December 

30, 1964.

Foster, Lucia, and Cheryl Grim. 

2010. “Characteristics of 

the Top R&D Performing 

Firms in the U.S.: Evidence 

from the Survey of Industrial 

R&D.” Center for Economic 

Studies Discussion Paper 

CES-WP-10-33.

Gardner, Todd. 2009. “Expanded 

and Enhanced Decennial 

Census Data for Research.” 

In 2008 Research Report: 

Center for Economic Studies 

and Research Data Centers. 

<www.ces.census.gov>

Griliches, Zvi. 1980. “Returns to 

Research and Development 

Expenditures in the 

Private Sector.” In New 

Developments in Productivity 

Measurement and Analysis, 

ed. John W. Kendrick and 

Beatrice N. Vaccara, 419–

462. Chicago and London: 

NBER/University of Chicago 

Press.

ing the Unisys running and 

recovering data. 

With Taylor, CES regained expertise in recovering and restarting 

the machine following frequent 

system crashes and in managing the flow of computing jobs 

to avoid conditions leading to 

crashes. She also understood 

how programmers had stored 

files on the Unisys. She solved 

many puzzles that would have 

slowed or completely stymied 

the recovery. 

Without Taylor’s expertise, it is 

likely that CES would only have 

been able to retrieve a handful 

of files, rather than thousands.

Role of RDC Partners

Help from our RDC partners was 

also very important to the success of the data recovery project. Our partners at the Berkeley, 

Michigan, Minnesota, and New 

York (Baruch) RDCs completed 

important groundwork to speed 

the process of converting data 

pulled from the Unisys into SAS 

datasets. Our Michigan and 

Minnesota RDC partners were 

also instrumental in acquiring 

the services of Rose Taylor.

MOVING FORWARD

CES needs partners to convert 

the recovered data files into 

formats useful for research. 

Data from hundreds of registers 

have been successfully copied 
U.S. Census Bureau Research at the Center for Economic Studies and the Research Data Centers: 2009 27 

Griliches, Zvi. 1986. 

“Productivity, R&D, and Basic 

Research at the Firm Level 

in the 1970s.” American 

Economic Review, 76(1): 

141–154.

Jordan, Willis K. 1965. 

“The Measurement of 

Performance Potential 

in Manufacturing 

Establishments.” Bureau of 

the Census Working Paper 

No. 18.

Kallek, Shirley. 1982. “Objectives 

and Framework.” 

In Workshop on the 

Development and Use of 

Longitudinal Establishment 

Data. U.S. Government 

Printing Office, Washington, 

DC. 

McGuckin, Robert H. and George 

A. Pascoe Jr. 1988. “The 

Longitudinal Research 

Database (LRD): Status and 

Possibilities.” Survey of 

Current Business, 68(11): 

30–37.

Nucci, Alfred R. 1998. “The 

Center for Economic 

Studies Program to 

Assemble Economic Census 

Establishment Information.” 

Business and Economic 

History, 27(1): 249–256.

Schaffer, William A. 1968. 

“Changes in the Structure of 

Manufacturing Employment.” 

Bureau of the Census 

Working Paper No. 26.
This document is an extract from “2009 Research Report: Center for Economic Studies 

and Research Data Centers.”

The full report is available at <www.census.gov/ces>.

This report has not undergone the review accorded Census Bureau publications and no 

endorsement should be inferred. Any opinions and conclusions expressed herein are 

those of the author(s) and do not necessarily represent the views of the U.S. Census 

Bureau or other organizations. All results have been reviewed to ensure that no 

confidential information is disclosed.