Understanding Society User Support

Hello,

I was wondering what the explanation is for the much smaller number of records in the employment status history file at wave 1 compared to the other wave 1 files? After reshaping it into wide form so there is one observation per person (as opposed to one observation per employment status spell), there are 11,462 observations - much less than the 50994 in the indresp file at wave 1. Was this only asked of a subset? On p.24 of the waves 1-3 user guide it states in the table that this module was ‘asked of first 6 months of first year’ but I cannot find any further explanation – does this mean this module was only asked of half the people? If so, is there any information at all on past employment/non-employment for the new participants (i.e., the non BHPS-parts of the UKHLS sample) prior to wave 1?

Thanks,

Amanda