Multiple migrations: Quantitative data approach

The MultiData project provided a more detailed picture of international movements, focusing on multiple migrations. Not every migrant moves once and permanently. Migrants often engage in international movement repeatedly at various points in their life courses. Young people often move for education or simply to experience life abroad. Later in life, people migrate for better career prospects or higher wages in other countries. Others move to join family members abroad. Upon retirement, some people choose to live in places with a better climate. People may move to one place over their life course, or to various places at different times when they decide to move. If people migrate more than once and to more than one destination, they are referred to as multiple migrants. Migration research so far has provided little evidence of such multiple migrations, beyond documenting individual and family life histories with qualitative evidence. These life histories offer in-depth information on particular groups, but they do not provide a broader picture that describes trends and outcomes of multiple migration.

The MultiData project was designed to address this gap in the existing literature and provide evidence on multiple migrations using a quantitative approach. To achieve this, the project utilised two types of quantitative datasets. First, evidence from existing social surveys conducted by academics was used to examine the volume and geography of multiple migrations. One surprising finding was that repeat and multiple migrants – those who move more than once to the same destination (repeat migrants) and those who move two times or more to different countries (multiple migrants)—are, in fact, the majority of movers who choose to move from one ‘old’ European Union member state to another. The survey data allowed to describe the freedom of movement in the EU in terms of the potential for mobility over the life course and for different sets of motivations. Thanks to the MultiData project, we know how the outcomes of migration differ for one-off and multiple movers; the latter may fare better in the destination country when considering the labour market situation and social ties. However, since multiple migrants have already lived in at least one other country, they do not seem to attach as strongly to the current destination.

Moreover, while traditional data sources such as registers and social surveys illuminate some aspects of multiple migrations, new data have the potential to provide a more comprehensive account of how multiple migrants move between various places over time. However, although big data offer opportunities for better understanding different aspects of migration, including multiple migrations, they should be used with caution due to data quality issues and possible biases, among other concerns. The MultiData project demonstrated that using various data sources presents challenges. One challenge examined in more detail was the ethics of secondary data use, as this was the main source of evidence for the project. Existing ethics guidelines for researchers focus largely on data production, but there are fewer resources on how to re-use data collected by others. Therefore, the project included a reflection on the ethical issues involved in working with data produced by other researchers. This is an important aspect of the project, which connects with the Open Science and Open Data movement.

Importantly, the results of the MultiData project were disseminated in academic journal articles on multiple migrations and migration research using quantitative methods. The results were also widely discussed at a series of international conferences in migration, sociology, European studies, research methods, and related fields. Another project outcome is a video animation describing some of the ethical issues involved in working with secondary data.

With its wide range of activities and publications, MultiData offers extensive material for academic and public debates on migration, fostering a more diverse and realistic understanding of migration, which can occur repeatedly and for different reasons even within a single migrant’s biography. As the MultiData project documents, this is important not only from an individual migrant’s perspective, but also from the perspective of destination countries and the outcomes that different groups of migrants experience in various areas of life, such as the labour market, social ties, and attachments.

Do you conduct analyses based on secondary social survey data? A video produced by the MultiData project provides a brief introduction to the ethical issues relevant to data re-use. The video production is linked to MultiData study based on secondary social survey data that examines multiple migrations.

DISSEMINATION OF RESEARCH

Publications

Triandafyllidou, A., Bivand Erdal, M., Marchetti, S., Raghuram, P., Sahin Mencutek, Z., Salamońska, J., Scholten, P., Vintila, D. (2024). Rethinking Migration Studies for 2050. Journal of Immigrant & Refugee Studies, 22(1), 1–21. https://doi.org/10.1080/15562948.2023.2289116

Salamońska, J. Complexity of the links between destination outcomes and migration patterns: West to West intra-European mobility. CMS 13, 12 (2025). https://doi.org/10.1186/s40878-025-00430-6

Salamońska, J. (2025), Motivation and Migration Trajectories of EU Citizens on the Move: Repeat and Multiple Migrants in Britain, France, Germany, Italy and Spain. Population, Space and Place, 31: e70040. https://doi.org/10.1002/psp.70040

Salamońska, J. (2025). Transferring Skills but Not Progressing: Labour Market Trajectories of intra-European West-to-West Movers. Journal of Immigrant & Refugee Studies, 1–16. https://doi.org/10.1080/15562948.2025.2532570

Błahuta, M., & Salamońska, J. (2026). “Ethical challenges in quantitative secondary data analyses. Insights from international migration research.” International Journal of Social Research Methodology, 1–19. https://doi.org/10.1080/13645579.2025.2608888

Conference presentations

4th Annual IMISCOE Standing Committee “Methodological Approaches and Tools in Migration Research” (Meth@Mig); Chemnitz University of Technology (Chemnitz, Germany); 3-4 April 2025; Paper Focusing on participants and related ethical challenges in secondary social survey research on migration

The Migration Conference, University of Greenwich, London (United Kingdom); 11-13 June 2025; Paper: International migrants in Switzerland: comparing the trajectories and outcomes of migrants from EU and non-EU countries

31st International Conference of Europeanists; Temple University, Philadelphia, Pennsylvania (USA); 25-27 June 2025; Paper: Multiple Migrants in the EU: Evidence from Social Surveys

ECPR General Conference 2024; Dublin, University College Dublin (Ireland); 11-16 August 2024; Paper: Is freedom of movement a panacea for economic problems at home? The mobility aspirations of young people in the EU

Online seminar: Re-using migration-related social survey data in a reflexive way - focus on ethical issues, ISP PAN; 17 June 2024; Paper: Ethical challenges in quantitative secondary data analyses. Insights from migration research

Midterm Conference of International Sociological Association Working Group 10 on Digital Sociology; Wydział Socjologii UW; Warszawa (Poland); 17 September 2024; Paper: Open Data: What ethical issues?

Annual IMISCOE Conference Migration and inequalities. In search of answers and solutions. Warszawa (Poland) 3-6 July 2023; Paper: Migration patterns and motives: Studying intra-EU movement over time and space

International Labour Process Conference, Padua (Italy); 21-23 April 2022; Paper: Linking patterns of migration with labour market integration: Analysis of intra-European movers

19th IMISCOE Annual Conference, Oslo (Norway) 29 June – 1 July 2022; Paper: Do types of migration trajectories matter for migration outcomes? Study of intra-European movers

The Migration Conference 2022, Rabat (Morocco); 7-10 September 2022; Paper: Re-conceptualising free movement: Empirical study on intra-European movers and their migration and motivation trajectories

Other activities

Workshop “Between Data and Dialogue: Focusing on Participants in Migration Research” 3-4 April 2025

Summer School “Feminist intersectional pedagogies: moving towards communities of solidarity”, 29 July – 5 August 2024, Nordic Summer University, Logumkloster; Paper: Does my research involve human subjects? 'Getting through ethics' of data re-use