VCF0006a Unique Respondent Number

QUESTION:
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Unique identification number

NOTES:
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GENERAL NOTE:
For non-panel cases this corresponds to 4-digit year of study followed
by 4-digit case id from the study as found in VCF0006.
For panel cases, this corresponds to 4-digit year of first year of 
time-series participation followed by 4-digit case id from first 
participation study .  For example, 1958 ANES panel cases (first 
interviewed in the 1956 anes) are numbered 1956xxxx where xxxx 
corresponds to the case ID the respondent had been assigned previously 
in the 1956 study; VCF0006, by contrast, includes the respondent's 1958 
NES case ID. 
Studies including panel cases as part of the overall study cross-section
are flagged in VCF00016.
1958 NOTE:
In the 1958 anes time-series study, V580007 and V580008 flags whether 
1958 respondents were previously interviewed in 1956.  However, some 
respondents flagged in these variables had been interviewed in 1956 not 
as part of the 1956 anes study's cross-section sample, but as part of a 
sample component intended for a separate 'panel' (non-cross-section) 
file.  Thus the actual count of cases from the 1958 study having 1956 
unique IDs in VCF0006a (as 1956xxxx, where xxxx is the 1956 ANES 
cross-section case ID) does not correspond with the count of cases 
flagged in V580007 and V580008 for previous participation in 1956.
1960 NOTE:
see 1958 note; cases flagged in the 1960 ANES study for participation 
prior to 1960 may have participated outside of the time-series cross-
section(s) in the year(s) of prior participation and may not correspond
to the count of cases found here for initial time-series participation.

TYPE:
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Numeric  Dec 0