Systematic literature reviews in migration studies: approaches to context-sensitive synthesis

With a burgeoning literature on migration, taking stock of what is known about a topic, pattern, or process is challenging. In many scientific fields, systematic literature reviews (SLRs) are a widespread response to this need. In migration research, SLRs are relatively rare. Most existing literature reviews are non-systematic and often geographically specific. The rarity of comprehensive SLRs might partly reflect migration researchers’ sensitivity to context-specificity and variation, and their well-founded scepticism towards empirical generalizations. In this article, we make a case for the value of SLRs for synthesizing quantitative findings on migration across diverse contexts. However, we foreground the interpretative nature of quantitative research in migration studies and explore approaches to synthesis that recognize exceptions and diversity as much as the search for unifying answers. Our discussion seeks to increase comparability in syntheses across contexts, all the while allowing reviews to convey disparity of findings. In contrast to common advice to narrow down research topics in SLRs, we demonstrate the feasibility of broader review questions. We exemplify our approach with reference to an extensive review of determinants of migration aspirations, drawn from survey-based research, in which determinants were differentiated in terms of the relative consistency and certainty of results.