This variable tells which of the marriages described in the marital history variables (mh1-mh8) is the linked marriage. For example, if obs_first_sipp_mar_num=1 then the first marriage is the one observed in the SIPP and the partner from that marriage is the linked spouse.

1	Linked marriage is first reported marriage described by mh1, mh2, mh_date1, and mh_date2
2	Linked marriage is first reported marriage described by mh3, mh4, mh_date3, and mh_date4
3	Linked marriage is first reported marriage described by mh5, mh6, mh_date5, and mh_date6
4	Linked marriage is first reported marriage described by mh7, mh8, mh_date7, and mh_date8
Sysmiss	When there is no linked marriage