A History of the European Demographic Observatory (ODE) Database

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A History of the European Demographic Observatory (ODE)
By Jean-Paul Sardon
The International Project of Short Term Demographic Trends Analysis (“Projet international
d’analyse démographique conjoncturelle”) established by Gérard Calot1, Director of the INED,
was the starting point for a database which later grew into the European Demographic
Observatory (“L'Observatoire Démographique Européen – ODE”). New methodology, which
permitted computation of the annual TFR when only the total number of live births and the age
structure of female population were available, was developed within the framework of this
project in the late 1970s. This enabled estimates of the TFR to be made several months or years
before the age-specific fertility rates become available. This methodology was also developed in
order to compute the monthly TFR, based on the total monthly number of events; figures could
be obtained very quickly, a few weeks after the end of a calendar month2.
The methodology of the database was written and the software developed by Gérard
Calot. In the early stages, only French data were collected and computed. Later data were added
from neighboring countries, such as West Germany (as it was at that time) and England and
Wales (not for the entire United Kingdom, as vital statistics were collected for each area of the
UK separately). There was a need to get figures for all countries to be as comparable as possible,
as it was evident that values of the age-specific rates were not independent of the way in which
they were computed. Indeed, when two consecutives cohorts are substantially different in size
(e.g., they were conceived at the beginning of a war) the values of the age specific rates may
vary considerably, depending on whether the data used for the computations are organized by
In addition to Gérard Calot, who was the chief developer of the database, acknowledgement and thanks must also
be given to Alain Confesson. From 1988 to 2004 the ODE team consisted of three members; Calot, Confesson, and
Jean-Paul Sardon. When Alain Confesson left the team there were several other people working on the database, but
usually on a temporary basis. At present, the ODE database is located at the Laboratory of Demographic and Social
Analyses (University of Thessaly, Volos, Greece), and Pavlos Baltas is in charge of the data updating.
2 For details, see Calot, G. and Nadot, R. (1977). Combien y aura-t-il de naissances dans l'année. Population, 1977
(special issue): 185-230; Calot, G. (1978). Pour une estimation rapide de l'indicateur conjoncturel de la fécondité.
Population 1978(3): 705-716; and Calot, G. (1981). L'observation de la fécondité à court et moyen terme.
Population 1981(1): 9-40.
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Lexis squares or by vertical parallelograms (i.e., age- or cohort-oriented). This was demonstrated
in a book by Gérard Calot3.
The analysis was later extended to include all European countries, both Western and
Eastern, as well as a select few others, giving birth to what at the time was called the “Projet
international d’analyse démographique conjoncturelle”. For some countries, such as Canada,
former Czechoslovakia, or Switzerland, where all data required for analysis were also available
at regional levels, the project encompassed data for provinces or cantons. A few years later, the
project began to include data on female and male first marriages and later also data on divorce
and general mortality.
In 1990, the methodology of the project was proposed to the Eurostat, which was in the
process of publishing a demographic yearbook based on data provided directly by national
statistical offices (NSO). This methodology allowed elimination of data divergence caused by
the diversity of national practices and the generation of comparable figures for all countries
included the yearbook. The proposal received strong support from Bernard Langevin, who was
in charge of Eurostat’s social statistics unit at that time. All demographic data collected from
countries of interest, as well as descriptions of statistical procedures and the software required,
were given to Eurostat. Several people who were entrusted with preparation of the demographic
yearbook attended training sessions at the INED. The “Projet international d’analyse
démographique conjoncturelle”, newly settled at the Eurostat, was named the Syscodem
(Système communautaire démographique) by François Begeot, who was responsible for its
At that time, the Eurostat data requests made to European NSOs were based on the data
request of the INED/ODE. A few years later the ODE was officially founded, and all
methodology, data processing, and software were renewed. Once the changes were completed,
the ODE offered to prepare all tables and graphs needed for the Council of Europe’s
demographic yearbook, named “Recent demographic developments”. The ODE performed these
duties from 1998 until 2005, when the Council of Europe brought all activities in the field of
demography to a halt.
Calot, G. (1984) La mesure des taux en démographie. Age en années révolues ou âge atteint dans l'année.
Incidence du choix de la définition. Application à la fécondité générale (France, 1946-1981). Paris: INED, 322 p.
(Travaux et Documents, No. 104). This book was also presented in the journal of Population: Calot, G. (1984). La
mesure des taux en démographie: taux par âge en années révolues et taux par âge atteint dans l'année: Présentation
d'un cahier de l'INED. Population 1984(1): 107-146.
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At the end of the 1990s, the NSOs proposed the use of a common form for demographic
data collection to streamline the four different types of requests being made by the ODE, the
Eurostat, the Council of Europe, and the United Nations. This was done, and the list of requested
data established by the ODE, adjusted to specific needs of the Eurostat (in terms of the format of
data), became the basis for the detailed collection of demographic data by the Eurostat, which
was supplemented by specific requests from the Council of Europe (data on flows and stocks of
migrants), and from the United Nations (data used for the UN yearbook).
However, when the Council of Europe ceased publication of the demographic yearbook,
the ODE, recognized as experts of the Council of Europe and not as an international body, was
excluded from being part of the international working group on data collection and was removed
from the list of recipients of international statistical data. This was unfortunate, not only for the
ODE but also for data users, as it affected data quality. The ODE hence had no direct contact
with the NSOs and, like all other data users, was obliged to download data from the Eurostat
website. Unlike before, when upon discovery of any error (e.g., the use of age definition different
from requested) the ODE would write to the NSO and this would be corrected, the ODE was no
longer able to identify the origins of an error, i.e. whether it stemmed from the original data files
submitted by a NSO or if it had occurred during data processing at the Eurostat. In other words,
the procedure of data checking became more difficult. When annual hard copies of national
demographic yearbooks were published, the ODE was obliged to check if the figures published
by the NSOs corresponded to those included in the ODE database.
By the end of the 1990s the Eurostat, which was unable to directly process data on its
own and was therefore obliged to ask the ODE to explain the computation of some indicators in
order to provide answers to some users’ inquiries, decided to put an end to this uncomfortable
situation. The Eurostat sent out a call for submission of methodological proposals for
computation of demographic indicators at the Eurostat, with the intention of replacing Syscodem.
In the end, the Eurostat selected the proposal of the ODE. Users of ODE data who are interested
in obtaining further details on ODE methodology and learning about how this database was built
up will want to refer to the publication4 that was prepared for the Eurostat.
Calot, G. and Sardon, J.-P. (2004). Methodology for the calculation of Eurostat’s demographic indicators.
Luxemburg: Eurostat: 146 pp. (Working papers and studies; 26). Available on line at