Survey content/variables
1.How does the amount of data collected in each wave vary by family unit members? 
In general, a substantial amount of detailed data is collected for the Head, and Wife/"Wife" if present. Considerably less detail is collected for other family unit members (OFUMs).
2.What data are available in the area of housing? 
The PSID collects many data elements about housing, including housing type, characteristics, ownership, tax, insurance, etc. A list of such items collected in each wave is available here.
3.Where can I obtain information regarding release dates for files? 
File release information is available through the News section of our website.
4.How does the PSID distinguish between main and secondary jobs in the data files? 

Up through the 2001 interviewing year, the PSID distinguished between Main and Extra jobs. Someone could not have an Extra job unless he/she held a Main job during the same time period. The extra job must be held simultaneously with the main job. We made this distinction between main and extra jobs throughout. If two (or more) employers overlapped, the interviewer was supposed to ask which was the main one during that time and note in an open ended question the overlap and the hours and earnings of both jobs. Then this overlap period was to be included in the extra job sequences (BD82-BD106/CE74-CE98). Those who are only temporarily laid off are still employed at a main job and, therefore, could have an extra job during that time period. However, those who are unemployed, whether looking or not, have no main job employer during the time in question. Hence, any small job they may have is considered a main job--since it's the ONLY job. Use the month strings and dates of beginning and ending employment in the work history to tell whether time at B/D72-74a or C/E64-66a is temporary layoff or unemployment.

Beginning with the 2003 interviewing year, the PSID dropped the main vs. extra job distinction as defined above. Jobs are now classified as "current main job", "most recent main job" or "other" job. If someone reports 2 or more current jobs, or 2 or more recent jobs that ended at the same time, the interviewer asks which job he/she considers his/her main job. That one is listed as the current (or most recent) main job. Any other job is listed as an "other" job. A job can be an "other" job even when it does not overlap with a current or most recent main job. This situation could arise, for instance, when someone reports two jobs, with the current main job beginning before the old ("other") job ended.

5.What information about physical and mental health is collected by the PSID? 
The PSID contains a wealth of information that can be used to study the health of Americans and their family members. Information collected in the main interview is summarized here. Health information collected in the Child Development Supplement is summarized here.
6.How has the occupation-industry code classification system changed? 
The PSID used a one-digit occupation code, and later a two-digit, until 1981 when the three-digit 1970 Census code became standard for the main jobs of employed Heads and Wives. It was also used for the most recent jobs held by Heads and Wives who were currently unemployed and looking for work and for any job held in 1980 by a Head or Wife who was currently retired or no longer in the labor force. Starting in 2003, all occupation-industry data has been coded using the three-digit 2000 Census code. A retrospective coding project used the 2000 Census to code first occupation and industry of all Heads and Wives as of 2003 and that of their fathers and mothers.
7.In some cases there are discrepancies from wave to wave for the age of the individual. Why is this? 
Ages of individuals are asked and reported in each wave of the study. But interviews are seldom taken exactly twelve months apart for the same family from wave to wave. In fact, a family responding early in the interviewing period one year might respond late in the next year’s interviewing period, with 18 or more months between interviews for annual interviews (from 1968-1997). Conversely, a late responder in one wave could be an early responder in the next wave. Since the PSID transitioned to biennial interviewing (1999 through the present), the age gap can widen even further. Because of interview dates, there is a good possibility that an individual appears to have aged excessively or not at all. Also, individuals’ ages or birthdates can be misreported. Consistency checks for age discrepancies have always been done internally, but they are not altered if it cannot be determined which age is correct.