Observatoire statistique transfrontalier de l'Espace franco-valdo-genevois : Using the French and Swiss censuses for transnational statistics Group of experts on population and housing censuses Pascal Oger Director INSEE Rhône-Alpes Roland Rietschin Director OCSTAT

1. Introducing the Cross-border Statistical Observatory of the Geneva border area (OST) 2. Uses of French and Swiss censuses in OST studies 3. Differences between French and Swiss census data 4. Contribution of census data to cross-border analysis 5. Possible improvements 6. Conclusions

1. Introducing the Cross-border Statistical Observatory of the Geneva border area (OST)

Spatial background The Cross-border Statistical Observatory of the Geneva area (Observatoire statistique transfrontalier, OST) was created in the first place to assess the impact of the bilateral agreements between CH and UE on the free circulation of people. It studies a territory which covers the departments of Ain and Haute-Savoie, on the French side, and the cantons of Geneva and Vaud, on the Swiss side. In a general way, in Switzerland, it is necessary to have a cross-border approach : the areas where people live and work cross the national borders.

Page 5 The "franco-valdo-genevois" territory km municipalities 2,56 millions inhabitants (2012) 1,28 million jobs (2012) Two main observation perimeters : The transnational Geneva urban area km 2 265municipalities inhabitants (2012) jobs (2012)

Page 6 Institution following the main principles of official statistics Made permanent through an agreement signed between the territorial actors (in Geneva and in France) Funded by the State of Geneva, the French state and the french regional and local collectivities who are signatories of the agreement Allow the sharing of skills, knowledge, methods and techniques between the statistical institutions. Characteristics of the Observatory

Main activities Yearly review : reference document on the demographic, economic and social trends Thematic studies : studies on transnational relevant themes Web site : Prospective studies : population and household projections Online economic trend data Answer to external demand

2. Uses of French and Swiss censuses in OST studies

Introducing the French and Swiss censuses First results of the new French population census at the municipal level published in 2009 (statistical reference date : 1 January 2006) First results of the new Swiss system (structural survey) at the cantonal level published in 2013 (statistical reference date : 31 December 2010). Data at the municipal level is possible for large municipalities (> 10,000) or through the pooling of several survey years. Main differences between France and Switzerland : –The French census is the source for legal population count. –The structural survey, a part of the new Swiss census system, is not the reference source for accurate counts of population, but is used to supplement the statistics based on register with additional variables

Overview of censuses uses in OST studies (1/2) Yearly review : –Since 2009, French census is used to describe the evolution and structure of population. –Since 2013, the Swiss structural survey is used to describe the population of Geneva and Nyon Residential migrations : data of the 2006 French census were used to analyse residential migrations from Switzerland to the Rhône-Alpes region. Urban audit : Eurostat centralizes data on over 300 European urban agglomerations, including Geneva. Data is provided by national statistical offices, and come largely from censuses. Demographic projections : French census data and Swiss population statistics are the basis of the projections of the transnational area population

Overview of censuses uses in OST studies (2/2) Cross-border workers : A count and a description of the French inhabitants working in Switzerland is an important contribution of the French census to the knowledge of the territory Housing stock and housing conditions : On the French side, both for the description of the state of the stock for the housing conditions, the main source of data is the population census. Cross-border workers of Swiss nationality : The combined use of the French census and Swiss statistics allowed in particular estimating the number of persons of Swiss nationality residing in France but working in Geneva.

3. Differences between French and Swiss census data

In France as in Switzerland, "exhaustive" censuses were dropped in favour of two different methods. Switzerland statistical system : System based on administrative registers (population, buildings and dwellings) To complete this system with additional information on the population, 200,000 people are interviewed each year for the structural survey. From one year to another, the samples are considered independent, and annual comparisons are possible. However, a single year of survey does not produce reliable results at the sub-cantonal level. Three to five years of survey can be aggregated to produce average results with sufficient precision at the sub-cantonal level. However, average results from pooling raises the problem of the comparability with French results that have a unique reference date. Major changes in census systems in the last decade

French census : Based only on annual surveys, no administrative registers are used Based on a collection that lasts five years, with the middle year as the statistical reference year. At the end of the five years cycle, 40% of the population in the 10,000+ inhabitants municipalities have been interviewed, as well as every inhabitants in the < 10,000 municipalities. Two consecutive years of reference have non-independent samples, therefore annual comparisons are strongly discouraged in favour of five-year comparisons. The information is available three years after the statistical reference year : Thus, in 2015, we have information relating to 2012, and can compare it to 2007.

4. Contribution of census data to cross- border analysis

Page 16 An example of contribution : Swiss cross-border workers living in France In the Geneva area, most cross-border workers live in France and work in Geneva. Swiss statistics on these workers are based on work permits. However, the information provided is limited, and Swiss nationals don't need a work permit and are therefore not included in those statistics. On the French side, the census counts all the cross-border workers, and provides multiple information on their households, housing, transportation, diplomas, etc. However, the French census does not allow declaring a second citizenship. Franco-Swiss dual citizenship being relatively common, French census results cannot be used directly to estimate the number of Swiss cross-border workers. The OST combines both data sources to built its estimates.

Very partial response to a local problem "false residences" in France The number of inhabitants and cross-border workers in French municipalities has a big impact on their financial allowance. Some mayors of French municipalities denounce a growing practice that consists in occupying permanently a residence in France, while being officially resident in Switzerland (some claim 20,000 false residents in the french Geneva area). French census takes into account the secondary residences, but with minimal information : –The number of secondary residences is 20,200, almost the same than in –Through another source based on fiscal data, we know that only 27.2% of the owner of residential residences live outside France. The census helps us to correct grossly overestimated estimates, but does not give the exact number of « false residence »

5. Possible improvements

Possible improvements The Swiss Federal Statistical Office and French INSEE participated in joint work on the censuses conducted by Eurostat : therefore the censuses are readily comparable and, allowing some adjustments, allows the OST to answer most questions on cross-border workers. However, in the context of cross-border statistics, some improvements can be enumerated, mostly for the French census : Adding information on secondary residences. Allowing the declaration of a second citizenship on the questionnaire. Using ISCO coding of professional categories Adding questions on self-assessed health

6. Conclusions

Conclusions The cross-border statistical observatory is a good example of why censuses are essential and indispensable, despite the existence and use of administrative registers : They cover all the population (including, for example, cross-border workers and their family). They allow us to cross information between several domains (familial situation, activity status of all members of the household, transportations, housing, …). International comparisons are more and more important to users (and not only in cross-border areas). Therefore the comparability of censuses in différent countries should remain the central agenda for european statistical agencies.

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