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Description

OCCHISCO is a uniformly coded classification of occupations that is consistent across all countries. It is the most complicated variable to code consistently in NAPP, and the present documentation does not fully cover the issues addressed. We will be progressively adding to the level of detail available on this variable. For example, we will occasionally provide examples of common responses below each code so that users will be able to see what responses were coded where. Users with queries about the coding of specific occupations should contact the NAPP staff in the first instance. Users interested in variation in occupational responses below the level of detail provided in the codes (e.g., distinguishing "caretakers" from "janitors") should look at the OCCSTRNG variable.

The codes for OCC were adapted from the Historical International Standard Classification of Occupations (HISCO) coding scheme. More information on HISCO is available in M.H.D. van Leeuwen, I. Maas and A. Miles. (2002) HISCO: Historical International Standard Classification of Occupations. Leuven: Leuven University Press. HISCO in turn is based on the International Standard Classification of Occupations from 1968, commonly known as ISCO-68. Information on HISCO can also be located at the HISCO database of occupational titles, and the International Institute of Social History.

More information on the adaptations we made to HISCO can be found in the article "Occupational Classification in the North Atlantic Population Project" (2003), Historical Methods,, Vol. 36, No. 2 (Part 2), pp.89-96.

Structure of the classification scheme
The classification scheme is hierarchical, in the sense that each digit in the 5 digit codes introduces a new level of detail. Codes sharing the same first 1, 2 or 3 digits are considered to be increasingly similar. For example, all people working in agriculture have the first digit 6. The first digit of a code indicates the "Major group" a person's occupation is in.

The second digit indicates a "Minor group" distinction. Continuing the previous example, people who have the first two digits "61" are farmers - who may specify what they are cultivating or tending - and farm managers. Thus, as well as sharing the characteristic of working in agriculture (6) they also share the characteristic of being owners or managers (61).

The first 3 digits denote the "Unit group" of an occupation. At the third digit level, we introduce more detail. For example, the unit group "612" indicates "Specialized farmers". Within this unit group, 4th and 5th digit distinctions known as "titles" or "headings" are made. For example, 61220 indicates "Field crop farmers," and "61230" indicates "Orchardists and fruit farmers."

Understanding headings
In general, if the last two digits of a code are "00" the heading is reserved for general titles. For example, in unit group "721" for "Metal smelter and furnace workers", the heading "72100" is reserved for responses such as "Metal smelter" and "Furnacemen."

If the last two digits of a code are "10" the heading is reserved for "not further specified" titles (often abbreviated "n.f.s." or "nfs" in syntax files), and codes ending in "20", "30" and higher multiples of 10 are reserved for responses with more detail on some aspect of the occupation. For example, 58210 is the code for "Policemen and detectives, employer unknown," whereas 58220 and 58230 are the codes for "Policemen and detectives, public service," and "Policemen and detectives, private service" respectively.

Headings ending in digits other than "0" (e.g., 2, 3, 4, 9) are generally reserved for frequent responses specific to a particular country that probably belong with responses sharing the same first four digits of the heading. For example, 61115 (Husbandman or cottar) and 61117 (Female farmer) could be classified with other general farmers (61110), but occurred frequently enough in Norway and Canada respectively that we felt they should be given a separate code for easy identification.

If the last two digits of a code are "90" the heading is reserved for "not elsewhere classified" responses. For example, 58290 is the code for "Other law enforcement officers."

The difference between "n.f.s." and "n.e.c." responses is that n.f.s responses are quite general, and may not offer much detail on the tasks and duties of the job. Conversely, n.e.c. responses are typically quite detailed in the information provided, but there are not enough similar responses to justify a separate heading.

Alterations to HISCO
Compared to HISCO we have reduced the overall number of headings, while still introducing new ones, and retaining more detail from vaguely specified occupations.

In general, we made the fewest changes to the structure of the HISCO codes in major groups 0 and 1 (professional workers). We re-organized the codes within major groups 2 (administrative and managerial workers), 3 (clerical workers), 4 (sales workers), 5 (service workers), and 6 (workers in agriculture). We made the most substantial revisions in moving people between major groups in the manufacturing and transport major groups (7, 8, 9).

In particular, we created codes for vague responses of the form "Works in [specified type of] factory," such as "Works in cotton mill." We grouped these workers with "Laborers" and titled, skilled workers in the same general industry.

We eliminated codes where HISCO made distinctions that were not consistently made in nineteenth century census data. For example, HISCO distinguished between hand and machine spinners. We found that most spinners did not specify whether they were spinning by hand or machine, more often giving information on what they were spinning (e.g., cotton, wool, silk), or a firm's name.

We introduced codes to handle vague occupations, as discussed above. We also created codes to retain linguistic and nominal distinctions above a rough frequency level. These distinctions are generally made in the fourth and fifth digit of the codes. For example, we distinguish between "Farm workers, specialisation unknown" (62110) and "Farmer's sons and other male relatives" (62113), because "farmer's son" was a numerically significant response in Canada. Both are considered part of the "Farm labourers and helpers, general farming and n.f.s" unit group (621).

Other variables Responses to the occupational questions also returned information that cannot be classified within an occupational classification scheme, such as relationship to workers, or indications of status. Please see the documentation for the variables OCRELATE and OCSTATUS.

Information on the products sold by retail workers (Major Group 4) is available in the variable PRODUCT.

Occupations were also coded into domestic occupational classification schemes in Great Britain, Norway and the United States. See the documentation for the following variables for more information.

Great Britain
INACTVGB
OCCGB
QOCCGB
ORDERGB
RETIRDGB

Norway
OC1HIRNO
OC1TRDNO
OC2HIRNO
OC2TRDNO

United States
OCC50US

Comparability

Those who had no occupation or whose occupation was unknown are classified together under "No occupation/unknown".

For the harmonized occupational variable, OCCHISCO, a single occupational code that best fit the range of occupational titles was assigned to each multi-coded group, even if the single code was not the best fit for each and every individual occupational title within the group. OCCHISCO codes were assigned with attention to preserving the job status and general occupational activity of the original occupation. Users with particular interest in specific occupations should consult the alphabetic occupational strings or the alternative occupational source variables SE00A462 for Swedish occupations, NO01A404 for 1801 Norwegian occupations, and IS01B421 or IS01B422 for 1901 Icelandic occupations.

In Sweden, ambiguous occupational titles are assigned a code of 99998 in the unharmonized occupational variable SE00A461, which are then assigned a list of multiple possible occupation codes in a separate variable, SE00A462.

For the 1819 Mecklenburg, 1801 and 1901 Iceland and 1801 Norway datasets, the unknown and NIU category (99999) contains people who have no occupation and are too young to work.

In Iceland and Canada, respondents reported a primary and a secondary occupation. Only the primary occupation of respondents is coded into this variable. To identify the secondary occupation of respondents in Iceland refer to IS01B433 and in Canada refer to CA91A455.

Universe

Availability

• Canada: 1871, 1881, 1891, 1901
• Iceland: 1801, 1901
• Mecklenburg: 1819
• Norway: 1801, 1865, 1875, 1900
• Sweden: 1900
• United States: 1880