COR 700 

                    SIBLING APPENDIX U

        Background Variables for the 1977 Sibling Study

Coversheet:  Sex of Sibling--Some errors in the 1975 data's
selected sibling's sex were found during the 1977 interview's
cleaning procedure.  The office IDs were not changed, but the
corrected sibling pair is reflected in XSMGP. Therefore, do not
use XIDOF77 to select sex-pair samples.

Sibling data is available for everyone that is code 01 or 10 on
XSTAT77. XRSP77 is a more specific coding of XSMGP and XR4TWIN,

Corrections to interview times and dates were made after
consulting the cover sheets. For interrupted interviews, the
second day was coded.

Q48.  As in 1975, the respondent's subjective perception of 
      whether he/she lived with both parents was used.

Q50.  Changes in the highest level of the head of household's     
      education were only made when 1) the head's occupation 
      would indicate an interviewer error and 2) the 1975 
      respondent had the same head of household and reported a 
      more logical education level for the head of household. The 
      changes made according to the above 2 criteria involved 
      changing 12 years of college to 12 years of schooling. One 
      case has a suspected error, but the 1975 respondent lived 
      in a different household, so it was left as 24 years of 
      schooling.
 
Q52b. The code 15 (not raised in same household because are 
      adopted, step or foster) was coded independently of Q51a.

Q58.  Labor Union Participation--There are discrepancies between 
      the responses to Q58 and Q87b. These must be left since 
      there is no way to ascertain which piece of information is 
      correct. The 16 cases added in COR281 had Q58 coded 
      according to their response in Q133b of the 1975 interview.

Q91.  Birthdate--If the respondent refused this information, we 
      did not try to obtain it through other means. 1975 data 
      (SSBAGE) will have to be used for birthdate.