Households and families Redesigned microcensus as of 2020

Microcensus means “small population census”. The microcensus is the largest annual household survey of official statistics in Germany. The statistical offices of the Federation and the Länder have conducted this survey since 1957. In the microcensus, roughly 810,000 people in about 370,000 households and collective living quarters, that is approximately one percent of Germany's population, are asked about their working and living conditions.

Evaluation of the results of the microcensus 2023

The new microcensus system has now become established since its redesign in 2020. As in 2022, the 2023 survey year ran without any restrictions in the implementation of the survey. The non-response rate for the first results from the 2023 microcensus at federal level is around 12% and thus remains at a similar level as in 2022.

Evaluation of the results of the microcensus 2022

  • The non-response rate was further reduced compared to both previous years.
  • The additional program “housing situation” was surveyed for the first time in the redesigned microcensus and is therefore only comparable with previous years to a limited extent.
  • Increased immigration in 2022 is not fully reflected in the microcensus, which may have effects on the interpretation of results.

The limitations in the survey implementation of the microcensus from 2020 and 2021 were no longer present in the survey year 2022. That is, the initial technical difficulties following the methodological redesign of the microcensus in 2020 and the effects of the Corona crisis did not have any significant effects on the 2022 microcensus. This is reflected, among other things, in the non-response rate, which was further reduced compared to the last two years. The non-response rate for the final results of the 2022 microcensus is approximately 8 % at the federal level (first results approx. 11 %), which is significantly lower than for the final results in 2020 and 2021 (final result in 2021: 14%; final result in 2020: 35%).

The additional program "housing situation" was surveyed for the first time in the redesigned microcensus. The questions from this additional program are only asked every four years in the microcensus, i.e. most recently in 2018 and thus before the methodological redesign. Due to the first-time implementation in the new microcensus, the results from the additional program are affected by methodological innovations that severely limit comparability with the results of previous surveys.

In the case of the Microcensus 2022, it must be taken into account that increased immigration in 2022, especially as a result of the Russian attack on Ukraine, may have an impact on the results: In the extrapolation, selected characteristics of the microcensus are adjusted to key figures of the population update, including citizenship. Due to the strong influx of people seeking protection from Ukraine in 2022, the microcensus did not fully record them. In the current population update, however, these groups of people are taken into account via the reports from the registration offices. When interpreting the results on the population without German citizenship, it should therefore be noted that the different foreign citizenships (especially EU third countries) may be overestimated and that Ukrainian citizenship in particular is underestimated. Moreover, this may also have effects on other characteristics of the microcensus, such as household structure and educational attainment.

Impact of the methodological redesign and the Covid-19 crisis on the microcensus 2021 results

A completely new IT system was set up for the redesigned microcensus from 2020; its introduction was accompanied by technical problems. Individual technical challenges continued in the 2021 survey year. Together with the partially ongoing effects of the corona pandemic, these led to restrictions in the survey conduct. Taken together, however, the effects were much less strong than in 2020 - analysis limitations may still occur in deep technical or regional breakdowns.

The average non-response rate for the final results of the 2021 microcensus is approximately 14% at the federal level (first results approx. 17%). This value is considerably lower than in 2020 (approx. 38%; final result approx. 35%). Thus, there is an improvement in the quality of the annual results in 2021 compared to 2020.

Impact of the methodological redesign and the Covid-19 crisis on the microcensus 2020 results

Summary:

  • The results from survey year 2020 onward are comparable with those of previous years only to a limited extent.
  • Due to the specific situation in 2020, the usual technical and regional level of detail of the microcensus results cannot be reached.
  • Generally, the quality of the 2020 microcensus annual results is still guaranteed at the federal level nevertheless..

Methodological redesign of the microcensus from 2020

The microcensus has been redesigned. The European labour force survey (LFS) has long been integrated into the microcensus. The European Union statistics on income and living conditions (EU-SILC) has also been part of the microcensus since survey year 2020 after having been compiled by a separate survey. Since survey year 2021, the survey of the use of information and communication technologies (ICT) in private households has also been included in the microcensus. These new components offer many new analysis options.

The redesign also involved changes to other features of the microcensus. The list of questions and the concept of the sample survey were modified, and with the intro­duction of an online questionnaire, the form of data collection were also changed. The results from survey year 2020 onward are therefore comparable with those of previous years only to a limited extent.

Detailed information on microcensus modifications from 2020 is contained in the paper entitled "Die Neuregelung des Mikrozensus ab 2020" (Rearranged microcensus as from 2020), which was published in the 6/2019 issue of the Wirtschaft und Statistik (WISTA) scientific journal.

For an overview and details also of earlier breaks in the time series that were due to methodological changes to the microcensus see here (only in German language).

There are some new explanations regarding microcensus variables while others had to be updated because of the new concept. A comprehensive overview is offered by the Glossary (only in German language) in alphabetical order and by subject..

Impact of the redesign and the Covid-19 crisis on the microcensus 2020 in general

A completely new IT system was set up for the redesigned microcensus; its introduction was accompanied by technical problems that affected the survey conduct.

The situation was aggravated by the pandemic in 2020, which made it nearly impossible to interview respondents face-to-face on the spot as had been common practice in the years before. Social distancing and stay at home orders had an effect not only on the face-to-face interviews in the households but also made preliminary on-site visits more difficult, which are necessary for sample specification. In addition to that, the official statistics agencies mostly refrained from sending out reminders to account for the other pandemic burdens the population had to bear. This means that the obligation to provide information was not as usually enforced. All these factors led to a lower response rate than is common for the microcensus.

Due to these problems, the average non-response rate for final results of the 2020 microcensus is approximately 35 % (first results approx. 38 %) at federal level, which is markedly higher than in previous years. This non-response was reacted to on the basis of a mathematical-statistical model.

More precisely, this means that non-response is distributed very unevenly across subject areas, regions and periods of time. Any distortions that may occur are therefore countered by calculating response probabilities before extrapolation (calibration to the key figures of population statistics). Information on the gross sample is needed for that purpose. As it was not possible either to cover the gross sample completely in 2020 (interviewers could make preliminary on-site visits to a limited extent only), a synthetic (artificial) adjustment frame was created to compensate for that. It was assumed that the 2019 sample distribution corresponds to the gross sample distribution of 2020 (the variables remain stable over that period). The usual procedure (calibration of the net sample using the gross sample) could thus be followed to calculate response probabilities for the 2020 microcensus at the level of the Länder. This improves the quality of the results.

The trade-off between the reliability of results and our publication practice has led to a conservative release policy in this case. Therefore, the usual technical and regional level of detail of the microcensus results cannot be reached due to the specific situation in 2020 described above.

Generally, the quality of the 2020 microcensus annual results is still guaranteed at the federal level nevertheless.

Impact of the redesign and the Covid-19 crisis on selected subject areas covered by the microcensus in 2020

Households and living arrangements

In the field of households and living arrangements, almost all results for the survey year of 2020 are robust. There are exceptions in specific (small) subpopulations, for example where results relate to same-sex couples.

Special evaluations can be made upon request after the data quality has been considered.

Migrant background

The microcensus 2020 figures on the population with a migrant background are comparable with those of previous years only to a limited extent. This applies especially to some subpopulations (such as persons born as Germans, naturalised persons) which vary the more the smaller they are (when broken down by country of birth, for instance). Apart from the general changes and methodological/technical limitations explained under “Impact of the redesign and the Covid-19 crisis on the microcensus 2020 in general”, this is due to modifications of the survey/the wording of the questions and to the way in which the migrant background was categorised methodically. Now that the methods used to categorise the migrant background have been refined, the group of persons who acquired German citizenship by birth is represented more accurately.

Special evaluations can be made upon request after the data quality has been considered.

Labour Market

As the pandemic has changed the situation on the German labour market considerably in many sectors, there is additional uncertainty as to how labour market results should be evaluated when they are released. Statements as to whether results are attributable to actual developments or to the methodological and technical limitations described above can thus be made only with certain reservations. These uncertainties increase with the level of detail (for unemployment rates with detailed regional or demographic breakdown, for example).

Special evaluations can be made upon request after the data quality has been considered.

Analyses of the quality of atypical employment data have revealed implausibilities which made imputations necessary. It is likely that the wording of the question on temporary employment was misunderstood by many respondents who filled in paper or online questionnaires on their own without interviewers providing explanations. A number of respondents answered yes to that question although they were not in temporary employment. For respondents who had completed an online or paper questionnaire in 2020 and 2021, the answer to the question about temporary employment was therefore imputed by means of a correction procedure (hot deck procedure). Here the probability that respondents are in temporary employment is derived from the response behaviour in the other interviewer supported modes of data collection (face-to-face, telephone interview) for the imputed values. Data on temporary employment were also partially imputed in 2022, as the adjustment to an improved questionnaire has not yet been completed for all survey modes.

There is a delivery obligation towards Eurostat for labour market data from the EU labour force survey, which has been integrated into the microcensus as a survey component. That obligation was met by supplying quarterly and annual data for the year 2020, with the aforementioned reservations about the quality of the results.

Education

When it comes to compensating for nonresponse, the education variables have been included for the first time in 2020, in addition to other variables. In the field of education, nearly all results for the survey year of 2020 are robust at federal level when time series are compared and results of the examination year of 2019 considered. Exceptions are specific results with a greater degree of detail, for instance on the transition from education to employment based on data for the first quarter.

Income and living conditions including housing

The data of reference year 2020 are not comparable with those of previous years as the voluntary survey was replaced by a partly compulsory one. A considerably larger sample is used now that the European Union statistics on income and living conditions (EU-SILC) has been integrated into the microcensus as a survey component. Since there is a general obligation to participate, the population of Germany is represented more accurately than it was before in the separate EU-SILC survey called “Leben in Europa“ in Germany. A large share of missings is generated, however, since answers to questions about living conditions are still voluntary. Answers to questions about income, on the other hand, are now mostly obligatory. How these methodological changes to the microcensus and the special situation in 2020 will impact the results on income and living conditions cannot be assessed at the time being. This also holds for the impact of the Covid-19 crisis on subjective perceptions and expectations of households regarding their individual financial and social situation during the survey period and for any effects it may have on results.

More information on the redesign of EU-SILC (microcensus component relating to income and living conditions) is available here (only in German language).

Publication practice modified for microcensus results from reference year 2020

In order to reduce the timespan between the end of the survey year and the provision of results, we distinguish between two types of results from survey year 2020 onwards: first and final results. Both first and final results are based on fully processed and validated data.

The final results are based on a larger number of surveyed households than the first results. This is due to the fact that some households which have received reminders provide information when the survey year is already over. That data material is then extrapolated by means of an updated key population figure. There may be deviations from the first results on account of a larger sample size and the updated extrapolation.

What has changed in the microcensus as of 2020?

The microcensus is a representative household survey which has provided data on the structure and the economic and social situation of the population for more than 60 years. Every year, one percent of the population is requested to provide information about topics such as family, life partnership, life situation, occupation, and education and training. The tried and tested design of the microcensus as an omnibus survey has been continuously developed to fulfil increasing data quality requirements. Since 1968, for example, EU-wide questions about labour market participation (Labour Force Survey, LFS) have been an integral part of the microcensus.

Increasing national and European data accuracy, timeliness and comparability requirements have raised the burden of household surveys both for the population and the statistical offices of the Federation and the Länder. This is the reason why similarities between and common characteristics of the different surveys have been used to fulfil the increasing requirements and, at the same time, reduce the relevant burden. The integrated microcensus is based on this approach.

Further information can be found in the following sections:

The road to an integrated microcensus

The Microcensus Act (MZG) of December 2016 forms the basis for the new integrated microcensus. The Microcensus Act provides for some changes with a view to reducing the population’s response burden despite increasing data requirements. The surveys of income and living conditions1 and of the use of information and communication technologies, which were conducted separately in the past, have been integrated into the microcensus in order to meet both national and European requirements. Regarding income and living conditions, for example, data are needed at a level below Land level. Furthermore, the reporting of sub-annual data on labour market participation that are harmonised at the EU level is to be improved. These challenges can only be met by increasing the sample size and conducting follow-up surveys within a calendar year.

Basic concept of the integrated microcensus

The basic idea of the new microcensus has been to integrate the surveys that were conducted separately in the past in one survey from 2020 onwards. As a result, a set of integrated official household statistics is obtained where the surveys of labour market participation, income and living conditions, and information and communication technologies represent individual subsamples of the one percent microcensus sample.

As the individual surveys show overlaps in terms of content, integration permits the individual lists of questions to be combined. Therefore, the microcensus survey will in future comprise a shortened list of core questions and further survey components. The information needed to answer the core questions and those of the various additional components is not collected successively based on sort of a modular approach. Instead, the list of questions combines the content of different subject areas.

The questions of the core programme are posed to all the randomly selected households whereas only part of all microcensus households (the so-called subsamples) are asked to answer the questions of the other survey components. Each household is included in no more than one subsample. Due to the increased importance of reliable data on social participation, the basic principle of compulsory response is also applied to essential elements of the newly integrated survey content.

The principle of including all households up to four times in the microcensus survey is maintained. The survey of households that are included in the labour market participation subsample is carried out twice instead of once a calendar year (subannual follow-up survey). This will permit seasonal fluctuations to be covered more appropriately. To keep the burden on respondents low, however, the subannual follow-up survey focuses on the key variables for measuring changes in the labour market. Data for supplementary structural variables are only collected in every second survey, that is, once a year as before.

New topics in the microcensus

The Federal Government has committed itself to attaching special importance to combating poverty and social exclusion in the framework of the Europe 2020 Strategy. This is why information about the risk of poverty is very important. Integrating the survey of income and living conditions into the microcensus puts the focus on income distribution, poverty, social exclusion and living conditions (housing, access to services, quality of life).

Other new topics on Internet access and use result from the integration of the survey on information and communication technologies into the microcensus. The focus of this survey section is on questions about the type, frequency and selected purposes of Internet use (for example, e-commerce, e-government, Internet security, digital skills or the Internet of Things). In addition, information is collected on what concerns and obstacles prevent people from carrying out certain Internet activities (for example, online purchases or giving out personal information via social media on the Internet).

Furthermore, the content of the national additional programme on “Housing” was extended by the Microcensus Act. In 2018 data on improved accessibility were collected for the first time. Owing to its importance for housing policy decisions and the need for detailed results, the whole one percent sample is asked to answer the questions of the additional programme.

Recording the so-called extended migrant background - that is, whether at least one of the parents has a migrant background - is another modification which has been included since the new Microcensus Act came into force. Until 2016 this information was only available every four years or in cases where the parents lived in the same household.

New methods of data collection

New survey tools and a multi-mode design facilitate participation of the respondents. For example, the microcensus questions could be answered online for the first time in 2020. As alternatives, personal or telephone interviews and paper questionnaires are still available to the respondents. The individual household members can provide their answers either in the same way or using different channels (face-to-face, telephone, online, in writing - by post).

Conclusion

The advanced microcensus survey and introduction of additional modes of data collection that take into account data quality and efficiency aspects facilitate the production of modern household statistics. Furthermore, conducting parallel surveys with some similar topics is avoided by integrating these surveys into the microcensus. This reduces data discrepancy and redundancy as well as dual efforts and additional costs.

More information

Detailed information on microcensus modifications is contained in the paper entitled "Die Neuregelung des Mikrozensus ab 2020" (Rearranged microcensus as from 2020), which was published in the 6/2019 issue of the Wirtschaft und Statistik (WISTA) scientific journal.

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Footnote:

1: The German name of the European Union Statistics on Income and Living Conditions (EU_SILC) has so far been LEBEN IN EUROPA.