Occupation is a characteristic of an individual's job and hence varies over time. There are occupation values reported for (potentially) two jobs in each wave of the survey. Occupation is chosen by summing earnings associated with the array of variables ws1occ1-ws1occ{max number of waves} and ws2occ1-ws2occ{max number of waves} in the 1990-1993 panels, and tjbocc1_1-tjbocc1_{max number of waves) and tjbocc2_1-tjbocc2_{max number of waves} in the 1996-2004 panels and choosing the occupation associated with the greatest total earnings. Thus occupation is the occupation from which greatest earnings are derived in the survey.

1	Managerial and professional specialty occupations
2	Technical, sales, and administrative support occupations
3	Other
Sysmiss