• Microcensus Scientific Use File 1985 Documentation and Data Preparation [in German] [.pdf]

• Persons (in private households and collective dwellings)
• Households

• Persons
• Families
• Households

10-06-1985

16-06-1985

Yes

x %

Dwelling, Household, Persons

The Microcensus is a single-stage, stratified cluster sample with a uniform sampling fraction for all strata. As a rule, the sampling fraction is 1 %; it applies to all sampling units (dwellings, households, persons). Until 2004, by contrast, variables of the supplementary and additional programmes and the European Union Labour Force Surveys (EU-LFS) were implemented using smaller sampling fractions, which sometimes varied from stratum to stratum. For example, from 1996–2004 the national average was around 0.45% but the sampling fractions at administrative-district (Regierungsbezirk) level varied (0.4 %, 0.6 %, 0.8 %, or 1 %).

Because the selection probability of the Scientific Use File (SUF) basically remains constant at 70%, design weights can be created on the basis of the inverses of the sampling fractions of the Microcensus (1 %) and the Scientific Use File (70 %): w = 1 / (0.01 * 0,7).

In the case of the SUFs of the 1973–1987 Microcensuses, the duplications and deletions carried out for the purpose of correction for non-response and adjustment to population data should be taken into account. While the deleted records are used when carrying out the design weighting, the duplicated records must be excluded.

If, on the other hand, the data are to be used in “unweighted” form, the duplicated persons must be removed from the dataset, while the persons to be deleted should be left in. In the case of analyses at household level, the duplicated persons should also be deleted because otherwise a household may comprise more lines in the dataset than persons it actually comprises. The SUFs include a special variable for the identification of the duplicated persons and the persons to be deleted.

In the Microcensus, as in all surveys, the sampling plan cannot be realised fully. Hence, undercoverage occurs in the form of non-response on the part of the households to be surveyed. Because households and their members are obliged by law to provide information for the Microcensus, non-response is due mainly to the fact that households could not be reached during the survey. Cases of non-response are corrected using the information that is available about the non-responding households.

Until 1989, the household size, the living situation, and the occupation of the head of the household were taken into account. Compensation for non-responding households was carried out by duplicating a surveyed household that had as similar a structure as possible.

In contrast to compensation, adjustment is carried out at person level.

Until 1989, adjustment to conform with benchmark figures from the intercensal population estimates was carried out by means of random duplication and deletion of person-level records within each administrative district (Regierungsbezirk) by sex and nationality (Germans/foreign nationals). To ensure that the sample corresponded to known population distributions, both duplications and deletions of records were carried out. Within the framework of the updating of the sample, new-construction activity covered only the status until nine months before the survey. Households who moved in in the meantime did therefore not have any chance of being covered. For this reason, duplications from the newly constructed dwellings of the previous year were carried out separately. The population living in institutions was also adjusted separately.

The final extrapolation factors result from the combination of the two-stage procedure of compensation and adjustment.

Until 1989, both the households duplicated or deleted in the first stage and the persons duplicated or deleted in the second stage were included.

In order to compare the results of the pre-1989 Microcensuses with the publications of the German Federal Statistical Office (Statistisches Bundesamt), the duplicated persons should be left in the dataset and the persons to be deleted should be excluded. When conducting household analyses, researchers can either have recourse only to the derived variables (so-called Bandsatzerweiterungen [record extensions, i.e. aggregated information at household level, e.g., “number of persons in the household: 5”, that is subsequently assigned to each of the five persons] and Typisierungen [types]) in the record for the head of the household or they can carry out a hierarchical analysis of all the records of the household. It should be noted that one or more household members may have been duplicated or deleted.

See [.pdf] (in German)