Studies conducted in historical populations and developing countries have evidenced the existence of clustering in infant deaths, which could be related to genetic inheritance and/or to social and cultural factors such as education, socioeconomic status or parental care. A transmission of death clustering has also been found across generations. One way of expanding the knowledge on intergenerational transfers in infant mortality is by conducting comparable studies across different populations.
Systematic research on urban-rural variation in demographic behavior is necessary to overcome dichotomous views resulting from studying cities and the countryside separately. After all, a web of interactions facilitating the diffusion of ideas and behavior connects cities and rural areas. That is why it is especially important to study the comportment of migrants moving between urban and rural environments.
The Intermediate Data Structure (IDS) is a standard data format that has been adopted by several large longitudinal databases on historical populations. Since the publication of the first version in Historical Social Research in 2009, two improved and extended versions have been published in the Collaboratory Historical Life Courses. In this publication we present version 4 which is the latest ‘official’ standard of the IDS.