Recent occupation concepts applied to
historical U.S. Census data
Peter B. Meyer
US Bureau of Labor Statistics, Office of Productivity and Technology1
April 1, 2009 (version 0u)
Preliminary and incomplete. Please do not quote or cite yet.
1. Introduction
One way to trace changes in a society over time is to track how the distribution of
people into occupations has changed over time. The U.S. has collected occupational
information in its population census every ten years since 1850. In principle one can
make detailed comparisons of the work force over time with this data,2 but there are a
number of practical challenges. This paper describes some changes in the long run
definitions of the work force and issues in extending these definitions into the past.
The concepts underlying how occupations were counted changed quite substantially
between 1850 and 1940, then stabilized. This paper documents the changes in definition
of who is covered by the United States Census and how, and changes in the definition of
employment that make these comparisons problematic. To some extent we can quantify
approximately how these definitional changes affected how many people, and which
ones, who were recorded as having an occupation.
Since the 1930s, several basic census definitions have remained stable. A person is
employed in a certain week if the person has a paid job or a job working at least fifteen
hours a week in a family business producing goods for market. The employed person
may not actually work at that job that week if on sick leave, vacation, or other temporary
leave. The labor force in a certain week is made up of the employed persons and persons
actively seeking employment during that week. These categories measure actual activity
.
A person’s occupation is a more complicated concept which has objective
components but also incorporates elements of the person’s social identity (Sobek, 2006).
1
For their advice and encouragement I thank Margo Anderson, Nina Baur, Nele Bracke, J. David Hacker,
Mindy Miller, Cindy Zoghi, and other participants at seminars at the ESSHC 2008 and RC33 2008
conferences. Views and conclusion in this paper are those of the author and do not reflect the views,
policies, or official conclusions of the U.S. Bureau of Labor Statistics.
2
For example, one might wish to analyze changes over time in work activities, earnings distributions,
licensing, union membership, education, or technological sophistication of the work force. In comparing a
population of individuals, one might then wish to hold occupation constant and compare the individuals
within occupations to one another over time. Another approach is to compare changes in each occupation
over time, or to evaluate the changes in the distribution of occupation sizes. In any of these cases it is
necessary to have some established category system of occupations which is comparable over time. The
official Census definitions change every ten years however. These have been standardized over time in
different ways by various efforts, but they do not address the changes in the boundary of who has an
occupation, the definitional, scope and coverage changes addressed in this paper.
1
For a person with a job, the occupation category is inferred by the Census Bureau based
on the tasks or the job title. If the person has multiple jobs in a particular week, the
person’s occupation is the one that paid the most or at which the person spent the most
hours. For a person who is not working, the occupation is self-declared and is expected to
be related to the person’s past work, training, or expected future work. There has been
ambiguity and change over time in the likelihood that an occupation would be recorded
for certain sets of people, for example a wife at home who is not currently working, or a
man who has ceased working but perhaps not permanently. By modern definitions these
people are either unemployed (if seeking work) or not in the labor force.
Before 1940, Census enumerators asked individuals for their occupations, and
persons reporting an occupation were categorized as having gainful employment. This
was the nearest substitute to the current labor force concept. They did not carefully
distinguish the person’s activity in a particular week (working, looking for work, or
neither) and so did not arrive at measures that neatly map into a labor force concept.
There were also distinctions between who was recorded as having an occupation in the
past and those who would be recorded as having an occupation now.
In the years between 1870 and 1930, there were differences in coverage of women
and of Native Americans from the ways that would apply now. There were other smaller
differences in defining occupations to be discussed in the paper. In the 1850 and 1860
censuses the measures were quite different from the present. Occupations were not
recorded for slaves at that time, and other classification differences from the present were
also large.
At the end of the paper there are some numerical estimates, drawn almost entirely
from other sources. First, we review the historical changes that lead us to have the
occupation numbers and categories we have now.
2. Census of Population history
A U.S. Census of Population has been conducted each ten years since 1790, because
the U.S. Constitution required such a count of persons by locality to help define
representative political districts and fair taxation across the states. The census data would
support changes every ten years (“decennially”) so that as citizens moved and grew in
number, the political districts electing the House of Representatives could be adjusted to
cover approximately equal numbers of citizens. The framers of the Constitution also
required that any direct taxes imposed by Congress would fall fairly and proportionately
on the populations of the states. For the first century, the counts were collected by
marshals, from the national law enforcement arm of the courts. The constitution
required a separate count of the slave and free population. (Anderson Conk 1980, p.8)
The Constitution did not call for collecting occupation or industry data, but it was
repeatedly suggested that it should (including by James Madison). In 1820, there was a
question about how many persons, including slaves, worked in three general economic
2
sectors, agriculture, commerce, or manufactures. These are by current conceptions
industry information, not occupational information. In the 1840 census, respondents
were to be asked the same questions within these seven (industry) categories: mining;
agriculture; commerce; manufactures and trades; navigation of the oceans; navigation of
canals, lakes, and rivers; and learned professions and engineers. Again it appears slaves
were included (Hunt, 1909). Starting in 1850 and ever since then, many respondents
were asked more precisely for their profession, trade, or occupation.
In the 1850 census, "profession, occupation, or trade" was requested but only of free
males over 15. 323 occupations were presented in the results, summarized under ten
general headings: commerce; trade; manufactures; mechanic arts and mining;
agriculture; law, medicine, and divinity; other pursuits requiring education; government,
civil service; domestic servants; and other occupations. The census director visited the
statistical offices of several European countries in the early 1850s to exchange lessons on
census practice.
The 1860 census was very similar to 1850, but now all free persons over 15, now
including females, were asked an occupation. An alphabetical list of 584 occupations
was presented in the results, according to Hunt (1909).3 The 1850 and 1860 results were
poor, in some unspecified sense, in Hunt's view. (p470)
In 1870, General Francis Walker took charge as the Superintendent of the Census.
Marshals continued to do the collection. The inquiry of occupation now went to all
person over 10 years of age. Starting with the 1880 census, marshals no longer collect
the data. The President appointed a Superintendent of the Census, and supervisors and
enumerators were hired. Hunt (1909) reported that quality improved with the 1890 and
1900 Censuses. The Bureau redefined the occupational category system each decade.
The category system became elaborated in detail about manufacturing in the early 1900s.
It was a large scale activity. Hunt reports there were more than 25 million copies of
instructions and forms ("schedules") for the 1900 population census of pop, and several
hundred supervisors, and 53,000 enumerators. The task was rushed.
There were more discussions of standardization across countries in the early 1890s.
"The International Institute of Statistics [recommended at its 1893 session] an
international classification of occupations ... and in 1907 named a commission to prepare
a technological glossary, in English, French, and German, of the designations of
industries and occupations which have been employed in the censuses of leading
countries, accompanied by a brief but exact description of the character of the work
covered by each term so used ... [The commission's] first report is to be made ... [in]
Paris, in May, 1909." Wright and Hunt, 1909. Citing the category system described by
Bertillon (1893).
Until this time, the Census infrastructure was temporary, existing just for a couple of
years before and after each decade’s canvass. In 1902, Congress established a permanent
3
I have not seen those results. IPUMS.org doesn't seem to have them online; they standardized these early
occupation results on the 1880 category system.
3
Bureau to conduct this and other surveys and analyses. This was expected to reduce loss
of knowledge and skills between Censuses and sustain a staff of professionals. Other
countries had done this around the same time.
A key analytical advance in 1910 was to ask two new questions along with the
occupation question which give the basic job facts. One was what “industry” the
employer was in. The other asked whether the respondent was an employee, or self
employed, or an employer (Anderson Conk, 1978). The existence of these related
questions allow the occupation question to break off from the sources of revenue and ask
about the worker’s own function or tasks.
Alba Edwards was in charge of the occupational statistics from 1910 to 1940, and
gradually reduced the use of industry information to classify the occupation. He had a
strong preference for an occupation system to give information about the skills and
intelligence of the worker. In the absence of measurable data about this he was
sometimes reduced to making inferences from demographic information about the
workers. He acknowledged that “certain specific occupations which technically are
skilled occupations were classified as semiskilled because the enumerators [found] so
many children, young persons, and women as pursuing these occupations as to render the
occupations semiskilled, even though each of them did contain some skilled workers”
(Edwards, 1917). Looked at from currently standard concepts, in which occupation is a
structural, functional classification of workers, Edwards improved the analytical
precision of the occupation categories by helping excise industry concepts from them, but
clouded them by de facto including demographic or social-economic elements. For a
more thorough discussion see Anderson Conk (1978, 1980).
The 1950 category system appears to have a good reputation among academics.
Matt Sobek of the IPUMS.org project extended its reach to the entire span of 1850-2000,
with jobs matched as well as possible from 1950 to the category system of the
respondent’s year. Since 1950 the classification has continued to be revised every
decade, and in major ways in 1980 and 2000.
2a. Summary: history going forward -- the historical process recording
the data
 Census starts in 1790, for political districting and taxation.
 Most Native Americans (Indians) were not counted.
 1850: Free male respondents first asked for their “Profession, occupation, or
trade” by U.S. marshals. Occupations were not categorized.
 1850s: International conferences on occupation collection in Censuses
 1860: All free respondents asked for occupation; household head, usually male, is
counted distinctively.
 1870: Slave category disappears.
 1870: Classification of occupations into 338 categories.
4
 Since 1870: The category system changed every decade since then.
 1880: Data collectors now political appointees not judicial aw enforcers
 1902-10: Now permanent civil service bureau collects data and categorizes into
occupations. Quality improves.
 1940: Switch to “labor force” definitions and concepts, de-gendered
 Since 1940: Relatively stable definitions and practices.
 1970: With each new system “dual-coded” data are now available.
3. Recent occupational classification practices
In recent decades the answers of respondents to the occupation and industry
questions in the decennial Census have been encoded into a three-digit occupation code
and a three-digit industry code, which are made available in the public-use micro
samples. A monthly survey conduced by the same Bureau, called the Current Population
Survey, asks questions and procedures which are similar to the decennial Census. This
data is used to derive unemployment statistics. The following description of practices for
the Current Population Survey is similar to the practices for the decennial Census. The
respondent (or a proxy respondent like a family member or neighbor) is asked
approximately these questions4 in this order:






(class of employer) Is this person’s employer a private for-profit company, a
nonprofit, self-employed, federal government, state government, or local
government?
What is the name of the person’s employer?
(industry) What kind of business or industry is it; what do they make or do?
Is it mainly in manufacturing, retail trade, wholesales rate, or something else?
(occupation) What kind of work does this person do? (For example: plumber, typist,
farmer)
What are the person’s usual activities or duties at the job? (For example: typing,
keeping account books, filing, selling cars, operating printing press, laying brick.)
The answers to these questions, four of which are open-ended text, along with the
respondent’s city, state, sex, age, and years of education are made available to specialized
“coders” in the Census Bureau’s National Processing Center in Jeffersonville, Indiana. I
visited that office and interviewed some of the specialists.
The open-ended answers are in the respondent’s handwriting, digitally scanned from
the decennial Census form, or were typed by the CPS interviewer onto a computer then
downloaded to the coder’s computer. The coders follow carefully documented
procedures to assign a three-digit industry code and an occupation code to the respondent.
The open-ended answers are not made available in the public-use samples, and may not
be available any more in any form.
4
http://www.bls.census.gov/cps/bqestair.htm shows the exact phrasing of these questions for telephone
interviews for a recent CPS. http://usa.ipums.org has the questions asked for each past U.S. census.
5
The respondent may have given a job title, but in the more challenging cases has
given too brief a description of the tasks. A coder may not be able to assign occupation
and industry codes based on the documented procedures, in which case the respondent’s
data is forwarded (“referred”) electronically to a specialist called a “referralist.” This
occurred in 17% of cases in a large 1997-8 sample (Couper and Conrad, 2001, p. 10).
The referralist can match the employer name to a giant list of known employers called the
Business Registry (which is the same as an earlier list called the SSEL), and may do a
variety of kinds of research on the employer or the words used in the answers to the
“kinds of work” and the “activities or duties”. The referralist may look up the employer
on the web, and also can refer to a number of books on occupations. Referralists told me
that there is some tendency for respondents to over-inflate the importance or prestige of
their jobs.
If the job is hard to classify exactly, there are occupation categories for a best-match,
usually with the text "not elsewhere classified" abbreviated in the title. For example, in
the 1990 categories we see “Engineers, n.e.c.”, “Managers and administrators, n.e.c.,” “
Therapists, n.e.c.” and a dozen others like that. This technique helps keep some
categories precise while making room to fit everyone, and by stretching these residual
categories it is easier to extend a long time series of a particular category system.
For purpose of this paper, the work force is the set of employed persons. An
employed person is one with a job that takes time and is expected to pay the jobholder in
money or in goods. The labor force is made up of these employed persons, and also the
unemployed who are available to work at a job, and are actively taking steps to find work
actively within the week preceding the measurement. These are the modern definitions.
4. Classifications of the Census data
The main classifications are in Appendix 1. The respondent’s description of the
work activity or job title was used by a Census Bureau employee to assign them into one
of the categories. When there are multiple numbers of classifications listed in table 1, it's
because the sources don't agree. One reason for that is that sometimes industry
information was compounded with occupational information. For example Anderson
Conk (1980) uses the example of “foreman and overseers (street railway)” which was
distinguished from “foreman and overseers (not specified).”
Histories of the occupation statistics treat top officials of the census as having had
strong inclinations which affect the way the jobs are reported (notably Anderson Conk,
1980, but also the earlier work). Francis Walker was in charge in 1870 and 1880 and he
tended to see the “sector” (industry) as important information to encode in the occupation
classification, although since 1920 there is a separate “industry” variable which
characterizes the employer’s field of activity. Carroll Wright was in charge for 1890 and
1900. Alba Edwards was an increasingly important official from 1910 to 1940. He
6
tended to elevate the importance of differences between jobs where workers used their
heads versus and those where workers used their hands.5
In Census-associated secondary surveys of business establishments, employers could
offer job titles they used, and not use the decennial census classification. For example, in
a 1880 census special survey manufacturing establishments (Weeks, 1884), employers
were invited to submit lists of the jobs at their establishment, and these were not
standardized. Meyer (2004) standardized these into a set of 300 jobs across all
establishments, but it does not match the HISCO classification or the classification in the
1880 census of households.
5. Categories that cut across occupation definitions
Some occupational categories have a clear continuity over time, such as those of
doctors, barbers, carpenters, laborers, or public officials. But most of the population was
not categorized in an occupation, or was considered in an occupation in some decades but
not others. A key principle was that a person's activity was almost always conceived of
as an occupation if and only if the person received pay for their time. To clarify this
through experience it is helpful to examine some of the sets of people who were
sometimes thought of as marginally employed or outside the system of occupations.
Native Americans. Indians, now called native Americans, were not defined by the
Constitution as citizens, and did not have representation in the U.S. and were at first
excluded from the Census. The sovereignty of North American Indian nations has been
redefined over time. By 1890, there was an ethnic category in the census for “civilized
Indians,” apparently meaning more or less the ones who had settled into fixed dwellings
and who were willing to be included in the American population. J. David Hacker
reports that perhaps 90% of Indians were excluded from the U.S. Census until 1920. In
1890, 1900, and 1910 there were special censuses of Indians, including occupation, but
the results were separate from the main Census of Population.6 This means on the order
of 250,000 persons were not in the main occupation counts until 1920.
Year
Estimate of Native
Americans not counted
1850 1860 1870 1880 1890 1900 1910 1920 1930
0.7
0.6
0.6
0.6
0.6
0.4
0.3
0.2
0.2
Slaves. The Constitution required a count of free citizens and a count of slaves. The
subject of slavery was very divisive, and after difficult bargaining the framers agreed to
count slaves as three-fifths of a person for purposes of a district's representation and
taxation, though slaves could not vote and did not themselves pay taxes.
5
Anderson Conk (1980), p. 62.
Anderson Conk, p. 16, and informal conversation with J. David Hacker. For more information I am
advised to consult: Hacker again; Historical Statistics of the U.S., especially the section by Matthew Snipp;
the work of Matthew Sobek of the Minnesota Population Center; and the census counting of Native
Canadians documented by Michelle Hamilton.
6
7
In 1850, owners of slaves were asked for a count of them. In 1860, the owner was
asked for a list of their names. After that, slavery was abolished legally and as a data
category. Counts of slaves seem to be fairly precise, because they were an owner’s
property, and the owner would count them as assets with some precision. A 1-in-20
sample has been computerized (Alexander, et al, 2003). From this we infer the
population was 3.9 million in 1960.
The census did not inquire about the occupations of slaves, nor was "slave" defined
as an occupation. Some slaves were specialized and skilled however. One can see this as
a tourist to George Washington's plantation, where among the slaves there were
metalworking and leather specialists, clothing makers, food processors, housekeepers,
and farm workers. By the modern concept of labor force, the American slaves were part
of it. Without having detailed knowledge of their life cycles and work patterns at hand,
let us estimate very roughly that 85% of them were employed in the sense of having work
to do, and expecting to receive housing and food in kind. Implicitly I figure that only 15
percent were too young, too old, retired, or disabled to be expected not to do work of
some known type. Recall that a slave who was sick or on a temporary break is still in
essence employed at an identifiable activity or occupation.
From Historical Statistics, (2006, p. 2-378), table Bb129-166, series Bb129-130:
Slave population from 1850 Census = 3,204,313*85% = 2.72 million were in work force
Slave population from 1860 Census = 3,953,760*85% = 3.36 million were in work force
Data source: 1860 slave population inferred from Hacker et al, Historical Methods.
Year
1850 1860 1870 1880 1890 1900 1910 1920 1930
Slaves
3
3.9
85% of slaves, imputed
as having occupations
2.55
3.32
Undercounts of blacks and others. Census procedures tend to undercount people,
since procedurally the enumerators must identify a person before recording them, and
there is no compensating mechanism to estimate those who have not been located.
People most likely to be missed are those who are disconnected from jobs and families
and stable homes. By some estimates blacks have been undercounted by over 10% in the
U.S. Censuses of 1870, 1920, 1940, 1950, and 1960 and perhaps others. (Coale, 1955;
and Alterman, 1969, pp 275-280). The fraction of the population that has been counted
has risen over time (Thorvaldsen, 2006).
Data source: Undercounted blacks – Alterman (1969), Coale (1950)
Year
1870
Census count
of blacks
4,441,830
Approximate
undercount
10%
Imputed to have
occupations
50%
Estimated missing
number with occupations
222,092
8
1880
1890
1900
1910
1920
1930
4,880,009
6,580,793
7,488,676
8,833,994
9,827,763
10,463,013
10%
10%
10%
10%
10%
10%
50%
50%
50%
50%
50%
50%
244,000
329,040
374,434
441,700
491,388
523,151
Wives and mothers at home. If not employed, these women do not have
occupations. This principle is of long standing. But because they were expected to be
dependents, women in past decades were less likely to be recorded as having an
occupation even if they were employed than they are now. There is a substantial
literature on this topic.
Bose (2001) evaluated how then-conventional roles for women affected the way the
1900 census data reported female-headed households and formally-unemployed
housewives. While the 1900 census reported that 22.5% of women had occupations and
were employed, Bose imputes others to have been managing boarders, working on family
farms or otherwise employed and arrived at a total of 46.4% of women aged 15-64 as
employed, with occupations. (Bose, 2001; and Anderson, pp. 507) Thus using 2000
definitions, twice as many women were working in 1900 than the 1900 census reported.
Thus many women in 1900 who were not recorded in an occupation category would,
now, be recorded as having an occupation if they submitted the same data to a current
census.
Carter and Sutch (1996) reported an important discovery, that according to the
returns from the census enumerators of 1880, over 40% more women were employed
than were reported in the official Census totals. It is possible that the same differences
exist for 1890 also, but cannot be detected because the original 1890 data was destroyed
in a fire. Partly for this reason it is best to use later estimates from the individual data
based on the public use samples, for example in Historical Statistics (2006) rather than
the official Census publications. The subject of this paper is the missing information on
occupations in the workforce in the micro data, not any gap between Census publications
and the underlying data.
Roberts (2007, p. 390) concludes after examining the census data on individuals and
other evidence that the proportion of married women working declined slowly from 1860
to 1900 to its lowest level in the early twentieth century. From 1920 to 1940 more and
more married women entered wage work, and increasingly rapidly until 1990 when the
growth leveled off.
Data sources: Women, 1870-1930: Roberts (2007) and Bose (2001), Abel and Folbre (),
Goldin (1990), and Carter and Sutch (1995?)
1850 1860 1870 1880 1890 1900 1910 1920
1930
9
Estimated Population
in millions
23.2
31.4
39.8
50.2
62.9
76
92
106
122.8
Persons with recorded
occupations, millions
(41% in 1910)
9.5
12.9
16.3
20.6
25.8
31.2
38
43.3
50.3
Estimate of women
"missing" by later
definition of occupation
3.72
2.51
3.19
4.02
5.04
6.08
7.37
8.46
9.83
Children and students. There is sometimes a lower bound on persons for whom an
occupation can be recorded. Based on the instructions to the enumerators, the lower
bounds on age were specified to be 15 years of age in 1850 and 1860, 10 years in 1880
and 1900, and 14 years of age in 1940-1960. In other years there did not appear to be any
restriction, although it has been reported that in recent years the lower bound is 16.
[Author to check the lowest ages recorded in the public use samples at IPUMS.] These
rule changes do not affect the total number of persons with a recorded occupation
because not many children below the minimum age for a given year are actually working.
However the counts for particular occupations such as unpaid farm laborer and domestic
servant could be affected meaningfully by the age changes (Sobek, 2006, p. 36).
Being a student is not an occupation but in some years has been recorded in lieu of
occupation. A youth or student with a paying part-time job or unpaid family work taking
15 hours or more per week is to be recorded as having an occupation.
Retired or unemployed. Since the 1970 census, there is classification for the
unemployed who have not worked in five years but would be willing to work. A
respondent who does not have a job but has had one less than five years ago and seeks
one now may describe themselves as having an occupation which is the customary job or
a previous job. A retired person, that is one who does not intend to return to a previous
line of work, is (since 1940) conceived of as outside the labor force, and does not have a
census-defined occupation (except in those cases where retired is a sort of occupation).
Moen (1994) summarizes a previous literature on the question of whether in the
1880-1910 data including occupation were collected on unemployed older men, even
when the persons were really retired permanently. In modern data, there is a retired
category in lieu of another occupation. The Census instructions over this period became
clearer and clearer in their attempts to get enumerators not to record occupations for
retired men but they did not have a sharp category for this.
In general, Moen (1994) reports that it is not clear how to distinguish the retired men,
although other authors have made imputations of how many were retired. In this paper
we accept Moen’s conclusion, and a man who reported an occupation is taken to be
intending in the future to work in that occupation. We do not attempt to impute a retired
category, although in fact some unknown number of those men were “retired” (in modern
language) and were reporting a past occupation, and this is probably a more extreme
problem in the earlier years.
10
Non-citizens and border-crossers. The census is a survey of people who live in the
United States. Likewise, persons crossing borders between home and work, legally or
otherwise, are counted in the census and their occupations recorded if they live in the
U.S. and not if they live in another country. (These numbers can be large. It has been
estimated recently is that 11% of Mexico's population lives in the U.S.) In all cases it
does not matter for measurement of “occupation” whether the employer or the workplace
is in the United States. For redistricting purposes, I believe only citizens count.
Military. A person in the military ordinarily has had an income, and was counted in
one of a very few general military occupation categories. For the 1990 census, some
military persons were categorized more closely by their work activity. For example, in
the 1990 data, a physician in the military would be in the occupation “physician”. That
change brought those people in alignment with the usual principle that the person’s work
tasks or activities, not the employer’s attributes, determines the occupation category. But
in 2000, the census returned to the principle that anyone employed by the military is in a
strictly military category.
The institutionalized. A persons might be hospitalized, imprisoned, in a
government or charity shelter for safety, or in special institutions for the aged or disabled
or mentally incapacitated. These persons count in the census, and could be reported to
have an occupation but only rarely do.
Tax evaders, illegally working, or doing illegal work. Individual data from the
census is not made available to law enforcement officials. A basic principle is that the
census data are to be an accurate count of persons, reporting the world as it is. Therefore
a person employed in criminal activities, or not paying taxes on employment may simply
report their activity as an occupation to the census. Gambling and prostitution are legal
in a few places in the U.S. I believe employment in these is reported in the occupation
category “personal service occupations, not elsewhere classified” or some similarly broad
classification.
Volunteers, hobbyists, and persons at leisure. A person devoted to volunteering,
for example giving tours at a museum without pay, or serving a religious institution or
political party without pay, is not employed, therefore these activities have not counted as
census occupations. A person delving into a hobby like stamp collecting has not counted
as having an occupation. There is however a self-employed category, and a person trying
without pay to invent something that will be valuable in the future may probably report
himself as self-employed as an inventor, and perhaps this would match an occupation. It
is not clear to me whether the rules on this have changed over time.
Apprentices. There were many apprentice occupation categories until 1960. If
payment was explicit, then certainly an apprentice had an occupation. If there was no
payment in the present but rather the prospect of a job in the future, it is unclear to me
whether this would sometimes be defined as employment and an occupation, or a student
role.
11
Households. In the 1850-1860 censuses it seems that households were described as
having one occupation, the principal occupation of the household head. Since then, the
occupation concept is closely attached to individuals, and never attached to households.
Can’t find, homeless, refused, or traveling. If after some efforts the Census
enumerators cannot reach a person, they can accept a secondary report on that
household.7 If the person has no identified home but generally resides in a locality I
believe this person is supposed to be included, and some homeless persons do have
occupations. A person who is traveling should be recorded, in the district where the
person lives (I believe) not where they temporarily are traveling to.
Thorvaldsen (2006) has an enriched, cross-national comparison of this category.
Persons in areas which were not then part of the United States. The United
States expanded to include Alaska and Hawaii in 1867, and to include Puerto Rico,
Guam, Virgin Islands, (in 1898?). Census data covered them (starting when?) Let us set
aside these categories for now.
Table 2. Summary about counting various groups over time
Sources: See above text section
Category of persons
Relation to occupation categories
Indians (Native Americans)
Excluded, by Constitution; over time, most descendants have become U.S. citizens
or showed up in Census data, e.g. could have occupations
Slaves
Counted separately; did not have occupations in 1850 or 1860; after that disappears
legally and as a data category
Wives and mothers at home
Not counted in 1850. Later, were less likely to be counted as having an occupation
(Bose (2001) especially if it were informal and through an ethnic enclave. "Bose
estimates that in 1900, 46.4% of women aged 15-64 'worked' in the formal and
informal home based economy, compared with a 1994 rate of 58.8%. According to
the 1900 census definition, 22.5% of women 'worked'." (Anderson Conk, 2002)
Children or students
Minimum age for an occupation has jumped around from 15 to 10 to 14 to 16.
"Student" is recorded in some years but is not by usual definition an occupation.
Retired or unemployed
Sometimes these are given categories in the occupation category system
Non-citizens and bordercrossers
These count if the household location is in the U.S. The location of the employer
doesn’t matter.
Institutionalized
In prison, hospital, disabled, charity shelter; these can have an occupation but
usually don't.
7
Informally Michelle Hamilton reports that the Canadian census enumerators were supposed to visit a
dwelling three times before giving up on getting a report from that dwelling.
12
Working illegally or
avoiding tax
Can be categorized in a Census occupation. No link to law enforcement. However
before 1880, Census enumerators were law enforcement officials.
Volunteers or hobbyists
Not counted as in an occupation unless they report as self-employed
Apprentices
Yes, if paid in money or in kind. If not paid, might be conceived of as students, and
are not employed.
Homeless; can't locate;
traveling
Can have an occupation based on information from others or remote location.
Refused to answer
Historically a small category. Can have an occupation if enumerator receives
information from others (I believe). Possibly a growing category.
6. Translation and standardization over time
The IPUMS project (at http://ipums.org) has mapped the occupations in all Censuses
since 1850 and all CPS years to the 1950 set of occupations. So if one downloads the
data from there, almost all employed persons from any year have an assigned occupation
from the 1950 occupation classification.
For more precision in recent data, Meyer and Osborne (2005) standardized the 19602003 period to have occupations from a harmonized classification based on, but coarser
than, the 1990 census classification. This category system is now available as the
variable occ1990 from IPUMS. A general issue in this area is that the further in time one
tries to translate, the greater the danger that there is no corresponding occupation. For
example, the blacksmith category was important in 1880, but has disappeared by 1980.
Even more difficult, the computer programmer category is important in 1990, but has no
close analogs a century before. Further work to make smarter imputations of an
occupation classification from years other than the years in which the data was collected
is in Meyer (2006).
7. Estimating the population beyond the boundary: history going
backward
In brief the issues are that going from the present back to 1940, there was little
change in little change in categories or official coverage, and we do not adjust for
undercount. For 1930 and before, women, especially wives, not counted the same way as
now. Also the Native Americans and perhaps the unemployed were counted differently.
From 1850 to 1910, Native Americans were much less likely to be counted because many
were not citizens of the U.S. and did not pay taxes. Before 1900, changing categories of
teenagers were counted differently. In 1860, there were slaves, carefully counted, but did
not have occupations recorded. In 1850, only men were counted.
The next table has rough estimates, all in millions of persons:
13
Graphing this:
140.0
total pop in millions
120.0
100.0
pop w ith occupations
(based on 41% in 1910)
80.0
60.0
40.0
20.0
w omen "missing" by
today's definition of
"occupation"
Native Americans
apparently not counted
18
50
18
60
18
70
18
80
18
90
19
00
19
10
19
20
19
30
19
40
0.0
slaves
8. Conclusion
Whether a person is in the U.S. labor force has an objective definition – an
employment, or a specific effort to seek work in a specified week. Occupation, however,
is an identity. (Sobek, 2006) A person who is not currently employed has some room to
specify an occupation based on past work, past training, or future intent.
Translating occupations over time is helpful for social-scientific comparisons (e.g.
the general effects of unionization, licensing, or technological change). But large
portions of the population are outside the occupational categories, and the limits have
been drawn differently over time. Among the challenges are narrow redefinitions of
categories, and insufficient data to match between them. A more difficult qualitative
challenge is that whole categories of people have shifted from having no identified
occupation, to having one. Specifically, most blacks in the U.S. in 1850 were slaves, and
outside the occupation category system. Most Indians were not, then, citizens in the
census. And by one estimate, 46% of adult women were working in 1900 if we use
current definitions, but only 23% were by the definitions in the 1900 Census. Much of
the population have transitioned or been redefined into the officially measured labor force
as financial and economic interaction has become pervasive, over and above ethnic,
racial, national, and gender categories.
A variety of steps might be taken to impute occupation to people in the census but
for whom there is not occupation information. Before 1930, it is possible to adjust for
women who are reported in the census and were likely to have been working. It is more
difficult to adjust for people who were not recorded in the Census at all. Before 1870,
large fractions of the population are missing from our occupational data – slaves did not
14
have a known occupation, for example, and in 1850 women were not asked for an
occupation.
15
Appendix 1. US Census occupational classifications
Sources: For 1850-60 categories, Hunt (1909). For 1870-1940 categories, Anderson
Conk (1980), p. 23. For more recent categories, http://usa.ipums.org. For the phrasing of
the question, Wright with Hunt (1900).
Census year
Number of categories
1790-1840 Censuses
The question asked, or other notes
No specific occupation question
1850
323
1860
1870
584
338
"Profession, occupation, or trade of each male person over 15 years of
age" and "Number of slaves" (without further detail on their activities)
"Profession, occupation, or trade of each person, male and female, over
15 years of age" and "Number of slaves" (without further detail on their
activities)
"Profession, occupation, or trade of each person, male or female"
"Profession, occupation, or trade of each person, male or female" over
age 10 and, of those, months unemployed during the census year.
Separately, months at school. Full list of occupations is at
http://usa.ipums.org/usa/volii/88occup.shtml
1880
276 or 265
1890
1900
1910
218
303
428 or 432
1920
572 or 574
Full list of occupations is at http://usa.ipums.org/usa/volii/92occup.shtml
1930
534
Full list of occupations is at http://usa.ipums.org/usa/volii/occ1930.shtml
1940
228, 221, or 451
Full list of occupations is at http://usa.ipums.org/usa/volii/94occup.shtml
1950
287
Full list of occupations is at http://usa.ipums.org/usaaction/variableDescription.do?mnemonic=OCC1950
1960
296
Full list of occupations is at http://usa.ipums.org/usa/volii/96occup.shtml
1970
441
1980
504
Full list of occupations is at http://usa.ipums.org/usa/volii/97occup.shtml
"(a) What kind of work was this person doing? (at least two words) (b)
What were this person's most important activities or duties?" Full list of
occupations is at http://usa.ipums.org/usa/volii/98occup.shtml
1990
2000 US Census (1%
sample)
504
Full list of occupations is at http://usa.ipums.org/usa/volii/99occup.shtml
510
Full list of occupations is at http://usa.ipums.org/usa/volii/00occup.shtml
""Profession, trade, or occupation" and, of those, months unemployed
during the census year
16
Bibliography
Alexander, Condon, Digman, and Hacker, 2003. Historical Methods 36:1 pp 21-26
Alterman, Hyman. 1969. Counting People: the Census in History. Harcourt, Brace & World:
New York.
Anderson Conk, Margo. 1978. Occupational Classification in the United States Census: 18701940. Journal of Interdisciplinary History IX:1 (Summer, 1978) 111-130.
Anderson Conk, Margo. 1980. The US Census and Labor Force Change: a history of occupation
statistics, 1870-1940. Yale University Press.
Anderson, Margo. 1988. The American Census: A Social History. Yale University Press: New
Haven.
Anderson, Margo. 2002. Review of Christine E. Bose’s Women in 1900. Journal of Social
History 36:2 (winter, 2002), 506-508.
Bose, Christine E. 2001. Women in 1900. Philadelphia: Temple University Press.
Carter, Susan B., and Richard Sutch. "Fixing the Facts." Historical Methods 29, no. 1 (1996): 524.
Couper, Mick P., and Frederick G. Conrad. 2001. Analysis of Occupation Coding in the Current
Population Survey. Report for Bureau of Labor Statistics.
Dillon, Lisa, and Matthew Sobek. Historical Methods.
Durand, John. 1948.
Edwards, Alba M. 1917. Social-Economic Groups of the United States. Journal of the
American Statistical Association XV: 645-653.
Goldin, Claudia. Economic History of American Women.
Hacker, Historical Methods.
Hunt, William C. 1909. The Federal Census of Occupations. Journal of the American
Statistical Association.
Meyer, Peter B., and Anastasiya Osborne. 2005. Proposed Category System for 1960-2000
Census Occupations. U.S. Bureau of Labor Statistics working paper WP-383.
http://www.bls.gov/ore/abstract/ec/ec050090.htm
Meyer, Peter B. (Ed.) 2004. The Weeks Report database, 4th edition. Available online:
http://econterms.net/weeksreport/weeksdoc.htm
Meyer, Peter B. 2006. Updated unified category system for 1960-2000 Census occupations.
http://pbmeyer/research/occs/SSHA2006/occ_defns.doc
Moen, Jon R. “The Unemployment and Retirement of Older Men: further evidence from
the 1900 and 1910 Censuses”, Historical Methods, Winter 1994, 27:1, pp 40-46.
Roberts, Evan. 2007. Dissertation.
Sobek, Matthew. “Occupations.” Historical Statistics of the United States, Millennial Edition,
vol. 2 pp. 35-40.
Thorvaldsen, Gunnar. 2006. Away from Home in the Census. Historical Methods.
U.S. Bureau of the Census. U.S. Census of Population: 1960. Subject Reports. Occupational
Characteristics. Final Report PC(2)-7A. U.S. Government Printing Office, Washington
D.C., 1963.
Weeks, Joseph D., (editor). 1884. Report on the Statistics of Wages in Manufacturing Industries,
1880 Census Vol. XX.
Wright, Carroll D., with William C. Hunt. 1900. History and Growth of the United States Census.
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