Data
Our analysis is based on individual life histories observed in population registers. Population registers are exceptionally good sources for individual, longitudinal, and contextual analyses.
In addition to cross-sectional snapshots of the population from periodic censuses, they include continuous registration of births, deaths, and marriages and recording of in- and out-migration as well. The data are individual but grouped into households, which we observe evolving over time (Alter 1988; Neven 2000: ch.1). In the East Ardennes, our sample is the population of Sart, a large municipality (56.9 km2) located between the towns of Spa and Verviers. This commune is unusual because the administration opened and updated two population registers between 1811 and 1846, while the population register system in the rest of Belgium was only instituted on 16 October 1846. Between 1812 and 1900, the population of Sart varied between 1,800 and 2,500 inhabitants. Our database includes 11,402 complete and incomplete biographies, which represent 199,196 person-years. The second sample is a cluster of three Hervian municipalities situated between Verviers and the Dutch border: Charneux, Clermont, and Neufchateau. Here observation starts on 16 October 1846 and ends in 1900. We observe 21,435 individual biographies and 254,409 person-years during these 54 years. The average population was 4,683, but it was slowly decreasing over time.3.