Update to COR681

After going through the exercise of mapping 1990
detailed occupations and industries to the 1970
major categories as exactly as we could, we realized
that this is not the best thing to do.  We already
have WLS individuals' occupations coded to the
1970 categories using their 1970 occupations; what
is the point of duplicating that classification (and
imprecisely, at that), with 1990 occupation codes?

SO, we decided to keep the basic *concepts* of the
categories the same between 1970 and 1990, but
allow whatever changes occurred in detailed occupations/
industries between 1970 and 1990 determine the
major category for 1990-basis industry and occupation.

This leads to the following 1990 Major Occupation/
Major Industry scheme:

----------------------
-- MAJOR OCCUPATION --
----------------------
 1   Professional and technical specialty occupations,
        Self-employed and without pay
 2   Professional and technical specialty occupations,
        Salaried and NA
 3   Executive, administrative and managerial occupations
        Salaried and NA
 4   Executive, administrative and managerial occupations
        Self-employed and without pay
 5   Sales occupations
        Not retail trade
 6   Sales occupations
        Retail trade
 7   Administrative support occupations, including clerical
 8   Precision producation, craft, and repair occupations
        Manufacturing
 9   Precision producation, craft, and repair occupations
        Construction
10   Precision producation, craft, and repair occupations
        All other and NA
11   Operators and Fabricators
        Manufacturing
12   Operators and Fabricators
        All other and NA
13   Service Occupations
14   Handlers, equipment cleaners, helpers, and laborers
        Manufacturing
15   Handlers, equipment cleaners, helpers, and laborers
        All other and NA
16   Farm operators and managers
17   Farm workers and related occupations
18   Military occupations


--------------------
-- MAJOR INDUSTRY --
--------------------
 1   Agriculture, forestry, and fisheries
 2   Mining
 3   Construction
 4   Manufacturing
 5   Transportation, communications, and 
        other public utilities
 6   Wholesale and retail trade
 7   Finance, insurance, and real estate
 8   Business and repair services
 9   Personal services
10   Entertainment and recreation services
11   Public administration
12   Professional and related services
13   Active duty military


The SAS code for these new categories are COR681.SAS3 (major
occupation) and COR681.SAS4 (major industry).  Notes to 
include in the final codebook are:

NOTE:  The 1990 Major Industry categories are selected
       to resemble the 1970 categories, but individual
       industries which may have changed category between
       1970 and 1990 (for example, US Postal Service) 
       keep their 1990 major industry designation.  No 
       attempt was made to reconcile these cases.

NOTE:  The 1990 Major Occupation categories are selected
       to resemble the 1970 categories, but individual
       occupations which may have changed category 
       between 1970 and 1990 (for example, Actors & 
       Directors) keep their 1990 major industry 
       designation.  No attempt was made to reconcile
       these cases.  The large number of such cases makes
       direct comparison between 1970 and 1990 Major 
       Occupation categories unadvisable.  For a list of 
       all such individual changes, see Kubitschek 1986 
       (CDE Working Paper 86-6).