The microcensus (with the integrated labour force survey) is a sample survey covering roughly 1% of the population in Germany each year. To obtain information on the total population from the data collected, these have to be weighted accordingly.
The microcensus weighting procedure uses key population figures from the continuous intercensal population updates, which are broken down by region, age, sex and citizenship. Intercensal population updates determine the current population by updating the results of the latest population census, using the results of birth, death and migration statistics.
The present adjustment does not change the weighting procedure but accounts for the latest population figures in weighting the sample data. Before the adjustment, the key population figures were based on the updates of results of the 1987 Census (former territory of the Federal Republic) and of the Central Population Register of the former GDR as at 3 October 1990 (new Länder and Berlin). In contrast, the key population figures which have now been used for weighting were obtained by updating the 2011 Census results.
The old and the new population figures differ from each other: the register-based census has shown that the number of people actually living in Germany on 9 May 2011 was 1.5 million lower than the number provided by the relevant intercensal update (-1.8%). According to the new population figures, the group of people holding foreign citizenship, in particular, is smaller than suggested by the update (-15%). The weighting of microcensus and labour force survey data which accounts for the new key population figures has a similar effect on results pertaining to the number of persons in employment and unemployed. In 2013, the total number of persons in employment was on average by 2.3% or 929,000 lower than the former weighted figures. There was a stronger decrease for men (-2.7%) than for women (-1.8%).
| Variable | former weighted result | new weighted result | ||
|---|---|---|---|---|
| persons in employment | employment rate | persons in employment | employment rate | |
| 1,000 | % | 1,000 | % | |
| Persons aged 15 years or over | ||||
| Total | 40,547 | 56.5 | 39,618 | 56.6 |
| Men | 21,780 | 62.1 | 21,193 | 62.3 |
| Women | 18,768 | 51.2 | 18,425 | 51.2 |
On average, the total number of unemployed was by 4% or 88,000 lower in 2013 (Table 2). There was a stronger decrease for men (-4.9%) than for women (-2.4%).
| Variable | former weighted result | new weighted result | ||
|---|---|---|---|---|
| unemployed | unemployment rate | unemployed | unemployment rate | |
| 1,000 | % | 1,000 | % | |
| Persons aged 15 years or over | ||||
| Total | 2,270 | 5.3 | 2,182 | 5.2 |
| Men | 1,294 | 5.6 | 1,231 | 5.5 |
| Women | 976 | 5.0 | 951 | 4.9 |
The new grossing of microcensus and labour force survey data impacts also on the deviations between the results of the microcensus and employment accounts.