Quebec population resources: towards an integrated infrastructure of historical microdata ( )

Transcription

1 Quebec population resources: towards an integrated infrastructure of historical microdata ( ) Hélène Vézina BALSAC, Université du Québec à Chicoutimi Claude Bellavance Centre interuniversitaire d études québécoises, Université du Québec à Trois-Rivières Lisa Dillon Programme de recherche en démographie historique, Université de Montréal Paper presented at the poster session for Historical Demography, XXVII IUSSP International Population Conference August 2013 Busan, Korea The starting point What is the context? Quebec has the advantage of an exceptional and remarkably well-preserved documentary resource with the wealth of birth, marriage and death certificates recorded by the Catholic Church since the early days of French settlement in the 17th century. More than 40 years ago, two major projects, the Programme de recherche en démographie historique (PRDH) and BALSAC, initiated the digital transcription and linkage of these parish records. More recently, Quebec data from the Canadian historical censuses prior to 1921 have also been digitized and formatted in databases by the Centre interuniversitaire d études québécoises (CIEQ) as well as the PRDH. A new partnership of these three groups aims to harmonize and integrate these datasets. This type of infrastructure is particularly well suited to the Quebec population, given the unique ways in which the population has evolved (initial founder effect, immigration characteristics, cultural mixing and the diverse history of regional populations). [1]

2 What is available now? The BALSAC population database All Quebec Catholic marriages ( ) + births and deaths from the Saguenay region ( ) = 3 million records pertaining to almost 5 million individuals genealogically linked The Registre de la population du Québec ancien (RPQA) Longitudinal record linkage of the entire Catholic population of Québec ( ): 700,000 baptismal, marriage & burial acts The Canadian historical census data Complete count for the cities of Quebec and Trois-Rivières for seven decennial censuses ( ); partial count for Eastern Quebec regions Why create the infrastructure? The objective is to preserve, highlight and develop this unique historical and scientific heritage by building an infrastructure to compile the available historical microdata on the Quebec population. The creation of this infrastructure will: 1) offer a longer period of observation which will enhance research opportunities both in the social and biological fields; 2) encourage comparative and multisectoral research as well as collaborations both at the national and international levels; 3) facilitate integration of new data and development of new tools for linkage and analyses; 4) promote training in relevant disciplines and collaborations both at the national and international levels (comparative research). [2]

3 Three main steps along the road Step 1: Fusion of the BALSAC and PRDH databases We plan a full fusion of the underlying relational databases enabling simultaneous and continuous updating of the longitudinal data as well as integration and linkage of new vital records. The two databases share similarities in their design which will facilitate this merge: each database is premised on a family record based on each married couple, and each uses record linkage protocols based on multiple name mentions in each certificate. We will need to compare and harmonize the methods of family reconstitution adopted by the two projects, including the treatment of names, the calculation of scores, automatic record linkage programs, the attribution of missing dates, the order in which parish acts are linked together, and the design of the relational databases. Work will also be done to standardize variables such as identification numbers, dates and the various codes used, for instance, for place names and occupations. Step 2: Harmonizing existing census data series and expanding the geographical coverage The infrastructure will contain the census microdata covering two urban environments (Quebec City and Trois-Rivières) and three regions mixing rural and urban environments (Gaspésie, Côte- Nord and Saguenay) which represent 918,000 individual entries (2/3 of these have been already digitized). These individuals belong to 161,000 distinct households which will be linked to the BALSAC database. Individuals Already entered To be entered Total Quebec City Trois-Rivières Côte-Nord Gaspésie Saguenay Total Households Already linked To be linked Total Quebec city Trois-Rivières Côte-Nord Gaspésie Saguenay Total [3]

4 Step 3: Linkage of census data to BALSAC families The linkage program recently developed by our group contains three modules: one for linking census data to BALSAC families; one for linking BALSAC families to census data; and one for linking sets of data from distinct censuses. Here, we present the process of linking census data to BALSAC families. 1. Preparing the census data: Comparison of census records to vital records is limited to nuclear families which must first be extracted from households. In addition to the nominative data, other variables that will be used to link records and to calculate a score are kept. 2. Nominative information at the heart of the linkage process: Data from the census and from BALSAC are transformed into a common structure: the nominative unit of comparison (NUC) which contains the names of the spouses. To compensate for the absence of the surname of the wife in census data, the name of each child is added to the NUC. Hence, there will be as many NUC for a census family as there are children (and a NUC containing only three elements for childless couples). Each potential candidate family from BALSAC is also organized as a NUC and this pool of NUC will provide candidates for each census family. 3. Matching criteria and score assignment: Based on the methods developed at BALSAC, The application performs various blocking operations that restrain each pool of candidates to the most logical set of potential matches. While nominative data, especially the presence of children, provide our most important linkage criteria, concordance of dates and age, place of residence and occupation are used in the comparison process to establish a score rating, which measures the degree of similarity between census and BALSAC families. 4. Beyond the families, individual fates: The candidate families are ordered according to their final score which is based on the rating scale whose variables are fully adjustable. When the final decision to link a census family to a BALSAC family is reached, the research assistant can also link individuals based on name and date consistency. [4]

5 Linkage Process of Census Data and Civil Records Canadian Census Joseph BALSAC Population Database Selected households Nuclear family within the household Joachim Bouchard Anna Liz Jos Anaïs Agathe E X T R A C T I O N BALSAC families - nominative elements - place of residence - ages - head of household s occupation Joachim Bouchard Anna Liz Jos Anaïs Agathe - nominative elements - place and date of marriage - place of residence (spouses and parents) - occupations (husband and spouses fathers) Nominative unit of comparison (NUC) Nominative units of comparison (NUCs) H FN H LN W FN C FN Joachim Bouchard Anaïs Joachim Bouchard Anaïs Anna Joachim Bouchard Anaïs Liz Joachim Bouchard Anaïs Jos Joachim Bouchard Anaïs Agathe N O M I N A T I V E P A I R I N G H FN H LN W FN C FN Joachim Bouchard Anaïs Joachim Bouchard Anaïs Anna Joachim Bouchard Anaïs Liz Joachim Bouchard Anaïs Joseph Joachim Bouchard Anaïs Sophie S E L E C T I O N - NUC + - family structure - other variables S C O R E A S S I G N M E N T - NUC + - other variables I N D I V I D U A L S L I N K A G E Research assistant List of candidate families (order based on score) Linkage decision [5]

6 What is the success rate of the linkage between couples found in the census data and BALSAC marriages? In the course of a study on mixed marriages in Quebec, couples found in the 1881 census for the rural region of Gaspésie and in the 1871 census for Quebec City were linked to marriages in BALSAC. The success rate was variable depending on the region, on the type of couples and whether or not children are present in the census. Gaspesie 1881 Quebec City 1871 Type of couples Endogamous Catholic 96% 76% Endogamous Protestant 83% 37% Exogamous Catholic, different ethnicity 91% 73% Exogamous Protestant, different ethnicity 67% 45% Exogamous Cross religion 74% 47% At least one child in the census 91% 70% No child in the census 83% 53% All couples 90% 67% n Source: Gauvreau et al. (2010), Cahiers québécois de démographie 39: The finish line What form will the resulting infrastructure have? Parallel to our two major data sources (vital events and census records), we intend to keep two databases which will be interconnected in real time. Our goal is to set up a model which will permit the capture, integration and merging of other future data. The new infrastructure will allow several types of linkage operations (birth, marriage and death certificates for family reconstitution, individuals and households across censuses, couples in censuses and in vital records) while ensuring their integration into a unified structure easily exploited by the researcher. [6]

7 We will also create a secure portal for researchers who want to use or even contribute to the infrastructure. Moreover, a large part of the historic data pre-dating 1912 will also be made available through a public portal. What data will be available for research? The infrastructure will make the following data available for research: 1) All marriage certificates since the implementation of parish registers in Québec in the early 17th century to This will enable automatic reconstruction of the genealogy of the Quebec married population over a period of three-and-a-half centuries; 2) Linked data based on three types of vital event records (birth, marriage and death certificates) from the beginning of the 17th century to The 2.3 million certificates will allow researchers to explore the historical demography of families over a 250-year period; Vital event records Period Marriages Births Deaths total ) The seven modern nominal censuses that have been released so far (1852 to 1911) for Quebec City and Trois-Rivières and for three rural/urban regions (Saguenay, Côte-Nord and Gaspésie). The entire census microdata (close to a million people) will be linked to corresponding vital event data. Number of individuals per census Region Total Quebec City Trois-Rivières Côte-Nord Gaspésie Saguenay Total [7]

8 Emerging research opportunities This vast array of biographical information will permit studies based on individual trajectories situated within families, households and communities and examined from a multigenerational perspective. The interconnection between civil records and the censuses, along with linkages across the censuses themselves, will allow for detailed studies on a crucial period in the history of the Quebec population (mid-19th century to post-1910). It will be possible to focus on the evolution and long-term consequences of phenomena such as cultural diversity, social mobility and intercommunity relationships. From a population genetics and biodemographical perspective, the infrastructure will considerably enrich research on the transmission of biological and sociocultural characteristics, on the genetic diversity in Quebec regional populations and on the factors that have shaped this diversity. These will translate into original data that can contribute to a better understanding of the genetic determinants of health. Collaborators The construction of the infrastructure involves three research groups and a team reflecting the multidisciplinary and multisectoral characteristics of the research that will result from the infrastructure. DEMOGRAPHY Bertrand DESJARDINS Université de Montréal Alain GAGNON Université de Montréal Danielle GAUVREAU Condordia University Richard MARCOUX Université Laval Marc TREMBLAY Université du Québec à Chicoutimi Hélène VÉZINA Université du Québec à Chicoutimi HISTORY Claude BELLAVANCE Université du Québec à Trois-Rivières Lisa DILLON Université de Montréal France NORMAND Université du Québec à Trois-Rivières POPULATION GENETICS Damian LABUDA Université de Montréal GEOGRAPHY Marc ST-HILAIRE Université Laval Acknowledgements This project is funded by the Canadian Foundation for innovation, the Quebec ministère de l Enseignement supérieur, de la Recherche, de la Science et de la Technologie as well as the Université du Québec à Chicoutimi, Université du Québec à Trois Rivières and Université de Montréal. [8]