Editorial

Population and Housing Censuses are an important cornerstone for National Statistical Systems. They provide a range of important statistics, relevant for policymaking, planning and monitoring but also functioning as reference point and sample frame for many other national and regional statistics. The population census is not only an important statistical instrument, but it has also proved to be a trigger for (often politically sensitive) discussions. Beyond issues like what to include in the census questionnaire (referring for example to questions about citizenship, ethnicity, religion) or how to collect, analyse and disseminate the information, the preparation of a population census requires decisions on managerial issues like the organisation of the statistical office, the census budget and the required IT infrastructure. Controversies between political or other societal groups on census results are also not uncommon. Because of such issues population censuses often mark a key moment in the development of a National Statistical System.

The UN Recommendations for the 2020 Round of Population and Housing Censuses are aimed at those being undertaken during the period 2014–2025 and guide countries on how to organise and arrange the population census. With countries all over the world already experiencing census field work for the 2020 Round and roughly a similar number still preparing, a Special issue of the Journal on this topic is indeed very timely. Studying the organisation, the methodologies and learning from the results of other censuses is for many countries an essential activity in preparing their own census methodology. This Special issue contains 25 articles and gives a broad and world wide overview of the many aspects of census taking. The length of the list, at the end of this issue, of articles published on this topic in this Journal since 1998 (Volumes 14–35) underlines the relevance of the Population Census discussions in the work of Official Statistics. For a more detailed introduction into the theme of this issue and the structure of the Journal, I can refer to the Guest Editorial by Jean-Michel Durr.

The third discussion on the SJIAOS discussion platform (www.officialstatistics.com) focusses on the definition of a census, its methodology and the relevance of census taking.

An important point for discussion is if the census should be defined by its unique methodology or are the outputs the main element of its definition? An item related to the definition of a census is the question if the often used criteria of individual enumeration, universality, simultaneity, defined periodicity, and capacity to produce small-area statistics, are still that relevant as essential features of a census?

On the necessity of a census methodology some authors question the theoretical soundness of the register based census. Readers are invited to contribute to the discussion by giving their opinion if such a theoretical base is really needed for a census, and why so?

Readers might also argue about the statement that the main theoretical risk with the register-based census approach is that it reverses the paradigm of statistics: it seems to only measure what is available, instead of properly defining first a concept and then develop a methodology to measure it.

Censuses are generally seen as expensive projects. The readers are invited to give an opinion on to what extent the limited use of census results, in particular for evidence-based policy making, is still worth the huge cost?

And finally, discussion contributions are expected on the statement that, in the current fast moving world, to produce census results only every ten years is not relevant any more.

You are invited to contribute to the discussions via www.officialstatistics.com.

It is an honour for the Journal that Jean-Michel Durr (INSEE, the French National Statistical Institute), well-known and respected expert on Population and Housing Censuses, accepted to be the guest editor for this Special. I congratulate Jean-Michel Durr, the authors of all articles and the team of reviewers for this fantastic result. It is also an honour to have the importance of the Population Census emphasised by Stefan Schweinfest, Director of the United Nations Statistics Department, in his guest editorial. I finally would like to express my sincere gratitude to INSEE and UNFPA in making it possible to publish this Special issue on-line as an open access issue, allowing official statisticians from all regions and countries of the world to take note of and learn from the rich examples given in these articles.

Last but not least, the March issue brings the fourth manuscript that took the 2019 Young Statisticians Prize (YSP 2019). Congratulations to James Farnell and Peta Darby from the Australian Bureau of Statistics who contributed with an article on Administrative data informed donor imputation in the Australian Census of Population and Housing.

I am pleased to also refer you to the Statistical Journal’s website (www.officialstatistics.com) with interviews with the authors of the four prize winning manuscripts, discussing their article and work and giving some background on the authors, as well as the interviews with many other colleagues in Official Statistics – prepared by the interview editor Nancy Torrieri.

I wish you pleasant reading of the interesting articles.