COR684
J. Sheridan
April 1999
Updated May 5, 1999
Updated August 27, 1999

***8/99***
The line occ=695, Ind=389 in the SAS70 module has missing data.
This was in the original Nam-Powers file.  The WLS has a handful
of cases with this occ/ind combination, however, so this missing
data line should be removed, and the occ=695, ind=389 people allowed
to default to the occ=695, industry indicated value.  
***Change made 8/99***

We needed to get the 1970 and 1990 occupational characteristics
(occupational education and earnings scores) into 3 digits for
the new version of the WLS data.  Using COR638 for the 1970
scores, I reran the ed70.sps and inc70.sps programs, changing
the code to report 4 digits rather than 2.  This updated SPSS
code is included in this COR (COR684.ED70SPS and COR684.INC70SPS,
respectively).  This output was then rearranged into proper 
occupation/split lines, and made into the SAS module COR684.SAS70.

Rob Warren re-created the 1990 scores (using COR639 programs
and data), and returned to us a completed worksheet.  This was
rearranged into SAS code, found in COR684.SAS90.

Please refer to COR638 (for 1970 Occupation characteristics),
and COR639 (for 1990 Occupational characteristics) for more
information about how these occupational education and earnings
scores were computed.

Update and Recommendations
--------------------------

In their 1997 work to produce an SEI index for 1990-basis Census Detailed 
Occupation categories, Hauser and Warren (1997) made several recommendations 
regarding the construction and use of occupational status scores.  First, 
they recommend against the use of SEI scores in general.  As they argue, 
"...in rudimentary models of occupational stratification, prestige-validated 
socioeconomic indexes are of limited value.  They give too much weight to
occupational earnings, and they ignore intergenerational relationships between 
occupational education and occupational earnings."  They recommend that "we 
ought to move toward a more specific and disaggregated appraisal of the effects 
of occupational characteristics on social, psychological, economic, political, 
and health outcomes."  To this end, the use of occupational education scores 
and occupational income scores themselves, rather than a weighted average of 
these scores (i.e., SEI) is recommended (see also Warren, Sheridan and Hauser 
1998).

The second recommendation in the Hauser and Warren (1997) paper is that a 
transformation of the raw occupational education and income percentages is 
preferable, because in their analyses it reduces heteroscedasticity in the 
residuals from the regression of prestige on occupational earnings and 
education.  They recommend transforming the raw percentages into started
logit scores:

     	ln [(yi+1)/(100-yi+1)]                                        

Where yi = percentage in occupation category who completed 1 or more years of 
college (for occupational education scores) or yi = percentage in occupation 
category who earned $10,000 a year or more in 1969 (for occupational income 
scores).      

References
----------
Hauser, Robert M. and John Robert Warren.  1997.  "Socioeconomic Index
of Occupational Status:  A Review, Update, and Critique."  Pp. 177-298
in _Sociological Methodology_, edited by Adrian Raftery.  Cambridge: 
Blackwell.

Warren, John Robert, Jennifer T. Sheridan, and Robert M. Hauser.  
"Choosing a Measure of Occupational Standing:  How Useful are Composite
Measures in Analyses of Gender Inequality in Occupational Attainment?"
_Sociological Methods & Research_.  27(1):3-76.