Migration studies has contributed significantly to our understanding of mobilities and migration-related diversities. It has developed a distinct body of knowledge on why people migrate, how migration takes place, and what the consequences are of migration in a broad sense, both for migrants themselves and for societies involved in migration. As a broadly-based research field, migration studies has evolved at the crossroads of a variety of disciplines. This includes disciplines such as sociology, political science, anthropology, geography, law and economics, but increasingly it expands to a broader pool of disciplines also including health studies, development studies, governance studies and many more, building on insights from these disciplines.

Migration is itself in no way a new phenomenon; but the specific and interdisciplinary study of migration is relatively recent. Although the genesis of migration studies goes back to studies in the early twentieth century, it was only by the end of the twentieth and the beginning of the twenty-first century that the number of specialised master programmes in migration studies increased, that the number of journal outlets grew significantly, that numerous specialised research groups and institutes emerged all over the world, and that in broader academia migration studies was recognised as a distinct research field in its own right. By 2018 there were at least 45 specialised journals in migration studies (Pisarevskaya et al., 2019, p. 462). The field has developed its own international research networks, such as IMISCOE (International Migration, Integration and Social Cohesion in Europe), NOMRA (Network of Migration Research on Africa), and the global more policy-oriented network Metropolis. Students at an increasingly broad range of universities can study dedicated programs as well as courses on migration studies. Slowly but gradually the field is also globalising beyond its European and North American roots.

Migration studies is a research field, which means that it is not a discipline in itself with a core body of knowledge that applies to various topics, but an area of studies that focus on a specific topic while building on insights from across various disciplines. It has clear roots in particular in economics, geography, anthropology and sociology. However, when looking at migration publications and conferences today, the disciplinary diversity of the field has increased significantly, for instancing bringing important contributions from and to political sciences, law, demography, cultural studies, languages, history, health studies and many more. It is hard to imagine a discipline to which migration studies is not relevant; for instance, even for engineering studies, migration has become a topic of importance when focusing on the role that social media play as migration infrastructures. Beyond being multidisciplinary (combining insights from various disciplines), the field has become increasing interdisciplinary (with its own approach that combines aspects from various disciplines) or even transdisciplinary (with an approach that systematically integrates knowledge and methods from various disciplines).

1 A Pluralist Perspective on Migration Studies

Migration studies is a broad and diverse research field that covers many different topics, ranging from the economics of migration to studies of race and ethnicity. As with many research fields, the boundaries of the field cannot be demarcated very clearly. However, this diversity does also involve a fair degree of fragmentation in the field. For instance, the field features numerous sub-fields of study, such as refugee studies, multicultural studies, race studies, diversity studies, etc. In fact, there are many networks and conferences within the field with a specific focus, for instance, on migration and development. So, the field of migration studies also encompasses, in itself, a broad range of subfields.

This diversity is not only reflected in the topics covered by migration studies, but also in theoretical and methodological approaches. It is an inherently pluralistic field, bringing often fundamentally different theoretical perspectives on key topics such as the root causes of integration. It brings very different methods, for instance ranging from ethnographic fieldwork with specific migrant communities to large-n quantitative analyses of the relation between economics and migration.

Therefore, this book is an effort to capture and reflect on this pluralistic character of field. It resists the temptation to bring together a ‘state of the art’ of knowledge on topics, raising the illusion that there is perhaps a high degree of knowledge consensus. Rather, we aim to bring to the foreground the key theoretical and methodological discussions within the field, and let the reader appreciate the diversity and richness of the field.

However, the book will also discuss how this pluralism can complicate discussions within the field based on very basic concepts. Migration studies stands out from most other research fields in terms of a relatively high degree of contestation of some of its most basic concepts. Examples include terms as ‘integration’, ‘multiculturalism’, ‘cohesion’ but perhaps most pertinent also the basic concept of ‘migration.’ Many of the field’s basic concepts can be defined as essentially contested concepts. Without presuming to bring these conceptual discussions to a close, this book does bring an effort to map and understand these discussions, aiming to prevent conceptual divides from leading to fragmentation in the field.

This conceptual contestation reflects broader points on how the field has evolved. Various studies have shown that the field’s development in various countries and at various moments has been spurred by a policy context in which migration was problematised. Many governments revealed a clear interest in research that could help governments control migration and promote the ‘integration’ of migrants into their nation-states (DeWind, 2000). The field’s strong policy relevance also led to a powerful dynamic of coproduction in specific concepts such as ‘integration’ or ‘migrant.’ At the same time, there is also clear critical self-reflection in the field on such developments, and on how to promote more systematic theory building in migration studies. This increase of reflexivity can be taken as a sign of the coming of age of migration studies as a self-critical and self-conscious research field.

An introduction to migration studies will need to combine a systematic approach to mapping the field with a strong historical awareness of how the field has developed and how specific topics, concepts and methods have emerged. Therefore, in this chapter, we will do just that. We will start with a historical analysis of how the field emerged and evolved, in an effort to show how the field became so diverse and what may have been critical junctures in the development of the field. Subsequently, we will try to define what is migration studies, by a systematic approach towards mapping the pluralism of the field without losing grip of what keeps together the field of migration studies. Therefore, rather than providing one sharp definition of migration studies, we will map that parts that together are considered to constitute migration studies. Finally, we will map the current state of the research field.

To provide a comprehensive overview of such a pluralist and complex field of study, we employ a variety of methods. Qualitative historical analysis of key works that shaped the formation and development of the field over the years is combined with novel bibliometric methods to give a birds-eye view of the structure of the field in terms of volume of publications, internationalisation and epistemic communities of scholarship on migration. The bibliometric analysis presented in this chapter is based on our previous articles, in which we either, used Scopus data from 40 key journals (Pisarevskaya et al., 2019, or a complex key-word query to harvest meta-data of relevant publications from Web of Science (Levy et al., 2020). Both these approaches to meta-data collection were created and reviewed with the help of multiple experts of migration studies. You can consult the original publications for more details. Our meta-data contained information on authors, years of publication, journals, titles, and abstracts of articles and books, as well as reference lists, i.e. works that were cited by each document in the dataset.

In this chapter you will see the findings from these analyses, revealing the growth trends of migration specific journals, and yearly numbers of articles published on migration-related topics, number and geographical distribution of international co-authorships, as well as referencing patterns of books and articles – the “co-citation analysis”. The colourful network graphs you will see later in the chapter, reveal links between scholars, whose writings are mentioned together in one reference list. When authors are often mentioned together in the publications of other scientists, it means that their ideas are part of a common conversation. The works of the most-cited authors in different parts of the co-citation networks give us an understanding of which topics they specialise in, which methods they use in their research, and also within which disciplinary traditions they work. All in all, co-citation analysis provides an insight on the conceptual development of epistemic communities with their distinct paradigms, methods and thematic foci.

In addition, we bring in some findings from the Migration Research Hub, which hosts an unprecedented number of articles, book chapters, reports, dissertation relevant to the field. All these items are brought together with the help of IT technologies, integration with different databases such as Dimensions, ORCID, Crossref, and Web of Science, as well as submitted by the authors themselves. At the end of 2020, this database contains around 90,000 of items categorised into the taxonomy of migration studies, which will be presented below.

2 What Is Migration Studies?

The historical development of migration studies, as described in the next section, reveals the plurality of the research field. Various efforts to come up with a definition of the field therefore also reflect this plurality. For instance, King (2012) speaks of migration studies as encompassing ‘all types of international and internal migration, migrants, and migration-related diversities’. This builds on Cohen’s (1996, p. xi–xii) nine conceptual ‘dyads’ in the field. Many of these have since been problematised – answering Cohen’s own call for critical and systematic considerations – but they nonetheless provide a skeletal overview of the field as it is broadly understood and unfolded in this book and in the taxonomy on which it is based:

  • Individual vs. contextual reasons to migrate

  • Rate vs. incidence

  • Internal vs. international migration

  • Temporary vs. permanent migration

  • Settler vs. labour migration

  • Planned vs. flight migration

  • Economic migrants vs. political refugees

  • Illegal vs. legal migration

  • Push vs. pull factors

Therefore, the taxonomy provides the topical structure—elaborated below—by which we approach this book. We do not aim to provide a be-all and end-all definition of migration studies but rather seek to capture its inherent plurality by bringing together chapters which provide a state-of-the-art of different meta-topics within the field.

The taxonomy of migration studies was developed as part of a broader research project, led by IMISCOE, from 2018 to 2020 aimed at comprehensively taking stock of and providing an index for the field (see the Migration Research Hub on www.migrationresearch.com). It was a community endeavour, involving contributors from multiple methodological, disciplinary, and geographical backgrounds at several stages from beginning to end.

It was built through a combination of two methods. First, the taxonomy is based on a large-scale computer-based inductive analysis of a vast number—over 23,000—of journal articles, chapters, and books from the field of migration studies. This led to an empirical clustering of topics addressed within the dataset, as identified empirically in terms of keywords that tend to go together within specific publications.

Secondly, this empirical clustering was combined with a deductive approach with the aim of giving logical structure to the inductively developed topics. Engaging, at this stage, with several migration scholars with specific expertise facilitated a theory-driven expansion of the taxonomy towards what it is today, with its hierarchical categorisation not only of topics and sub-categories of topics, but also of methods, disciplines, and geographical focuses (see Fig. 1.1 below).

Fig. 1.1
A flowchart of migration studies taxonomy. It is divided into disciplines, methods, topics, and geographies. All the divisions are further divided into subunits.

The structure of the taxonomy of migration studies

In terms of its content, the taxonomy that has been developed distinguishes various meta-topics within migration studies. These include:

All the topics in the taxonomy are grouped into several branches: Migration processes, Migration Consequences, Migration governance and Cross-cutting. In Fig. 1.2 below you can see how many journal articles, books, book chapters and reports can be found in the migration research hub just for the period of the last 20 years. The number of items belonging to each theme can vary significantly, because some of them are broader than others. Broader themes can be related to larger numbers of items, for instance ‘migration forms’ is very broad, because it includes many types and forms of migration on which scientific research in this field chooses to focus on. On the contrary, the theme of ‘governance processes’ is narrower because less studies are concerned with specific processes of migration management, such as criminalisation, externalisation or implementation.

Fig. 1.2
4 different distribution patterns of migration processes, migration consequences, migration governance, and cross-cutting topics in migration research.

Distribution of taxonomy branches in the Migration Research Hub

The various chapters in this book can of course never fully represent the full scope of the field. Therefore, the chapters will include various interactive links with the broader literature. This literature is made accessible via the Migration Research Hub, which aims to represent the full scope of migration studies. The Hub is based on the taxonomy and provides a full overview of relevant literature (articles, chapters, books, reports, policy briefs) per taxonomy item. This not only includes works published in migration journals or migration books, but also a broader range of publications, such as disciplinary journals.

Because the Hub is being constantly updated, the taxonomy—along with how we approach the question of ‘what is migration studies?’ in this book—is interactive; it is not dogmatic, but reflexive. As theory develops, new topics and nomenclature emerge. In fact, several topics have been added and some topics have been renamed since “Taxonomy 1.0” was launched in 2018. In this way, the taxonomy is not a fixed entity, but constantly evolving, as a reflection of the field itself.

3 The Historical Development of Migration Studies

3.1 An Historical Perspective on “Migration Studies”

A pluralist perspective on an evolving research field, therefore, cannot rely on one single definition of what constitutes that research field. Instead, a historical perspective can shed light on how “migration studies” has developed. Therefore, we use this introductory chapter to outline the genesis and emergence of what is nowadays considered to be the field of migration studies. This historical perspective will also rely on various earlier efforts to map the development of the field, which have often had a significant influence on what came to be considered “migration studies”.

3.2 Genesis of Migration Studies

Migration studies is often recognised as having originated in the work of geographer Ernst Ravenstein in the 1880s, and his 11 Laws of Migration (1885). These laws were the first effort towards theorising why (internal) migration takes place and what different dynamics of mobility look like, related, for instance, to what happens to the sending context after migrants leave, or differing tendencies between men and women to migrate. Ravenstein’s work provided the foundation for early, primarily economic, approaches to the study of migration, or, more specifically, internalor domestic migration (see Greenwood & Hunt, 2003; Massey et al., 1998).

The study of international migration and migrants can perhaps be traced back to Znaniecki and Thomas’ (1927) work on Polish migration to Europe and America. Along with Ravenstein’s Laws, most scholars consider these volumes to mark the genesis of migration studies.

The Polish Peasant and the Chicago School

The Polish Peasant in Europe and America—written by Florian Znaniecki & William Thomas, and first published between 1918 and 1920—contains an in-depth analysis of the lives of Polish migrant families. Poles formed the biggest immigrant group in America at this time. Thomas and Znaniecki’s work was not only seminal for migration research, but for the wider discipline of sociology. Indeed, their colleagues in the Department of Sociology at the University of Chicago, such as Robert Park, had a profound impact on the discipline with their groundbreaking empirical studies of race and ethnic relations (Bulmer, 1986; Bommes & Morawska, 2005).

Greenwood and Hunt (2003) provide a helpful overview of the early decades of migration research, albeit through a primarily economic disciplinary lens, with particular focus on America and the UK. According to them, migration research “took off” in the 1930s, catalysed by two societal forces—urbanisation and the Great Depression—and the increased diversity those forces generated. To illustrate this point, they cite the bibliographies collated by Dorothy Thomas (1938) which listed nearly 200 publications (119 from the USA and UK, 72 from Germany), many of which focused on migration in relation to those two societal forces, in what was already regarded as a “broadly based field of study” (Greenwood & Hunt, 2003, p. 4).

Prior to Thomas’ bibliography, early indications of the institutionalisation of migration research came in the US, with the establishment of the Social Science Research Council’s Committee on Scientific Aspects of Human Migration (see DeWind, 2000). This led to the publication of Thornthwaite’s overview of Internal Migration in the United States (1934) and one of the first efforts to study migration policymaking, Goodrich et al’s Migration and Economic Opportunity (1936).

In the case of the UK in the 1930s, Greenwood and Hunt observe an emphasis on establishing formal causal models, inspired by Ravenstein’s Laws. The work of Makower et al. (1938, 1939, 1940), which, like Goodrich, focused on the relationship of migration and unemployment, is highlighted by Greenwood and Hunt as seminal in this regard. The New Palgrave Dictionary of Economics regards Makower and Marschak as having made a “pioneering contribution” to our understanding of labour mobility (see also the several taxonomy topics dealing with labour).

3.3 The Establishment of a Plural Field of Migration Studies (1950s–1980s)

Migration research began to formalise and expand in the 1950s and 1960s (Greenwood & Hunt, 2003; Pedraza-Bailey, 1990). A noteworthy turning point for the field was the debate around assimilation which gathered pace throughout the 1950s and is perhaps most notably exemplified by Gordon’s (1964) typology of this concept.

Gordon’s Assimilation Typology and the Problematisation of Integration

Assimilation, integration, acculturation, and the question of how migrants adapt and are incorporated into a host society (and vice versa), has long been a prominent topic in migration studies.

Gordon (1964) argued that assimilation was composed of seven aspects of identification with the host society: cultural, structural, martial, identificational, behavioural, attitudinal, and civic. His research marked the beginning of hundreds of publications on this question of how migrants and host societies adapt. The broader discussions with which Gordon interacted evolved into one of the major debates in migration studies.

By the 1990s, understandings of assimilation evolved in several ways. Some argued that process was context- or group-dependent (see Shibutani & Kwan, 1965; Alba & Nee, 1997). Others recognised that there was not merely one type nor indeed one direction of integration (Berry, 1997).

The concept itself has been increasingly problematised since the turn of the century. One prominent example of this is Favell (2003). Favell’s main argument was that integration as a normative policy goal structured research on migration in Western Europe. Up until then, migration research had reproduced what he saw as nation-state-centred power structures. It is worth reading this alongside Wimmer and Glick Schiller (2003) to situate it in broader contemporary debates, but there is plenty more to read on this topic.

For more on literature around this topic, see Chaps. 19, 20, and 21 of this book.

Indeed, these debates and discussions were emblematic of wider shifts in approaches to the study of migration. The first of these was towards the study of international (as opposed to internal) migration in the light of post-War economic dynamics, which also established a split in approaches to migration research that has lasted several decades (see King & Skeldon, 2010). The second shift was towards the study of ethnic and race relations, which continued into the 1970s, and was induced by the civil rights movements of these decades (Pedraza-Bailey, 1990). These two shifts are reflected in the establishment of some of the earliest journals with a migration and diversity focus in the 1960s—the establishment of journals being an indicator of institutionalisation—as represented in Fig. 1.3. Among these are journals that continue to be prominent in the field, such as International Migration (1961-), International Migration Review (1964-), and, later, the Journal of Ethnic and Migration Studies (1970-) and Ethnic & Racial Studies (1978-).

Fig. 1.3
A line graph of the total number of journals versus years. The plot has a positive slope that gradually increases with the increase in the year.

Number of journals focused on migration and migration-related diversity (1959–2018). (Source: Pisarevskaya et al., 2019, p. 462) (R&C Race & Class, IM International Migration, IMR International Migration Review, SE Studi Emigrazione, PP Patterns of Prejudice, JBS Journal of Black Studies, JEMS Journal of Ethnic and Migration Studies, PDR Population and Development Review, IJIR International Journal of Intercultural Relations, ERS Ethnic & Racial Studies, JIS Journal of Intercultural Studies, RSQ Refugee Survey Quarterly, REMI Revue Européenne des Migrations Internationales, MW Migration World, JRS Journal of Refugee Studies, LCC Language, Culture, and Curriculum, APMJ Asian and Pacific Migration Journal, HM Hommes et Migrations, Id. Identities, PSP Population, Space, and Place, CDEMP Cultural Diversity and Ethnic Minority Psychology, IMIS IMIS-Beitrage, EH Ethnicity & Health, CS Citizenship Studies, JSIE Journal of Studies in International Education, REE Race, Ethnicity, and Education, EJML European Journal of Migration and Law, JIMI Journal of International Migration and Integration, NJMR Norwegian Journal of Migration Research, Ethn. Ethnicities, GN Global Networks, JIRS Journal of Immigrant & Refugee Studies, ML Migration Letters, ZAA Zeitschrift für Ausländerrecht und Ausländerpolitik, IJMHSC International Journal of Migration, Health, and Social Care, LS Latino Studies, FJEM Finnish Journal of Ethnicity and Migration, Mob. Mobilities, JDHE Journal of Diversity in Higher Education, NJMR Nordic Journal of Migration Research (merger of NJMR and FJEM), IZAJM IZA Journal of Migration, CEEMR Central and Eastern European Migration Review, MS Migration Studies, CMS Comparative Migration Studies, Mov. Movements, JMH Journal of Migration History, M&S Migration & Society. For more journals publishing in migration studies, see migrationresearch.com)

By the 1970s, although several new journals of migration studies had emerged and the field was maturing in terms of theory-building, there remained a lack of interdisciplinary “synthesis” (Kritz et al., 1981; King, 2012). This is reflected in the research of Levy et al. (2020). Based on citation data showing who migration researchers cited over the years, Fig. 1.4 maps the embryo-like development of migration studies every half-decade from 1975 to the present day. In the early decades it shows distinct “epistemic communities” (represented by colours) clustered together based on disciplines in migration research. For example, the earlier decades show economists focused on development (sky blue); economic sociologists analysing the labour market behaviour of migrants (royal blue); demographers (green); and sociologists studying the assimilation topic (red) mentioned above. By the late 1980s, a new cluster of social psychologists (yellow) emerged, with a combination of demographers and economists clustering (pink) in the 1990s. The figure shows an increasing coherence to the field since then, as the next section elaborates, but the 1970s and 1980s was a period of disciplinary differentiation within migration studies.

Fig. 1.4
9 cluster images of co-citation measured from 1974 to 1979 and progressing till 2015 to 2018. It can be observed that the cluster grows and becomes come compact with an increase in years.

Co-citation clusters of authors cited in migration studies literature 1975–2018. (From Levy et al., 2020, p. 18)

Although the field may not have been interdisciplinary in the 1980s, it was indeed multidisciplinary, and research was being conducted in more and more countries: This period entailed a “veritable boom” of contributions to migration research from several disciplines, according to Pedraza-Bailey (1990), along with a degree of internationalisation, in terms of European scholarship “catching up” with hitherto dominant North American publications, according to Bommes & Morawska, (2005). English-language migration research was still, however, dominated by institutes based in the global North and the ‘West’.

Interdisciplinarity and Internationalisation in Migration Studies: Key Readings

There have been several publications dealing with the development of migration studies over the years. These readings identify some of the key points related to interdisciplinarity in the field, and how the field has evolved internationally.

Talking Across Disciplines has been used as a standard textbook in migration studies for several years. It represents the first effort towards highlighting the key ideas of the multiple disciplines in the field. It offers an introduction to the contributions these disciplines, as well as critical reflections on how those disciplines have interacted.

International Migration Research is one of the first attempts to explore and synthesise migration studies from an interdisciplinary perspective. In this book, scholars from multiple disciplines provide a state of the art of the field which illuminates the contrasts between how these disciplines approach migration studies. It is one of the first works in which migration studies is understood to be an institutionalised field of study.

In this book, readers are introduced to the idea that migration studies developed as a policy-driven field in several countries in the twentieth century. Not only did this entail diverse policy priorities, but also diverse “paradigms” of knowledge production in terms of terminology, concepts, and measures. This diversity reflects different national science policies. There are chapters reflecting on these processes from multiple continents, and from both “old” and “new” immigration countries.

In the decades before the 1990s—with a heavy reliance on census and demographic data—quantitative research abounded in migration studies (Greenwood & Hunt, 2003). But by the beginning of the 1990s, a “qualitative turn”, linked more broadly to the “cultural turn” in social sciences, had taken place (King, 2012). In other words, migration studies broadly shifted from migration per se, to migrants. King notes the example of geographical research: “human geography research on migration switched from quantitatively inclined population geography to qualitatively minded cultural geographers […] this epistemological shift did not so much re-make theories of the causes of migration as enrich our understanding of the migrant experience” (King, 2012, p. 24). Indeed, this is also reflected in how Pedraza-Bailey (1990, p. 49) mapped migration research by the end of the 1980s into two main categories: (i) the migration process itself and (ii) the (subjective) processes that follow migration.

Even though it is clear that migration studies is made up of multiple communities—we have already made the case for its pluralist composition—it is worth re-emphasising this development through the changing shape and structure of the ‘embryos’ in Fig. 1.4 above. The positioning of the clusters relative to each other denotes the extent to which different epistemic communities cited the same research, while the roundness of the map denotes how the field can be considered an integrated whole. We clearly see that in the period 1975–1979, the disciplinary clusters were dispersed, with loose linkages between one another. In the 1980s through to the mid-1990s, while some interdisciplinarity was emerging, several clusters, such as demographers and psychologists, were working largely within their own disciplines. In other words, in the 1970s and 1980s, authors working on migration referred to and were cited by other scholars primarily within their own disciplinary traditions. In this time, although a few migration journals had been established, this number was small compared to today. Without many scientific journals specialised in their topic, migration scholars were largely reading and publishing in disciplinary journals. By today—particularly in Europe—this has changed, as the increasing roundness of the maps demonstrate and as the rest of this chapter substantiates.

3.4 Expansion of Migration Studies Since the Turn of the Century

In the 2000s the expansion of migration studies accelerated further (see Fig. 1.5). In 1975, there were just under 350 articles published on migration; there were 900 published in 2000; in 2017, over 3000 articles were published. This growth not only involved a diversification of the field, but also various critical conceptual developments and the rise of an increasingly self-critical approach to migration studies. One of these critical developments involved a move beyond a strong focus on the national dimension of migration and diversities, for example in terms of understanding migration as international migration, on integration as a phenomenon only within nation-states, and on migrants as either being connected to the ‘home’ or ‘host’ society.

Fig. 1.5
A line graph of the number of articles versus years from 1975 to 2017. The plot of document numbers follows a positive slope.

Number of articles, per year, in migration studies dataset based on advanced query of Web of Science for Migration Research Hub, 12 March 2019. (Based on Levy et al., 2020, p. 8)

Several key publications marked this important turn. Wimmer and Glick-Schiller (2002) refer to “methodological nationalism and critique the notion of taking the nation-state as a given as if it were a natural entity. In fact, for Wimmer and Glick Schiller, this way of understanding reality helps contribute to nation-state building more than it enhances scientific knowledge. In a similar contribution, Favell (2003) critiques the concept of ‘integration’ as naturalising the nation-state in relation to migration. Favell’s main argument was that integration as a normative policy goal structured research on migration in Western Europe. Up until then, migration research had reproduced what he saw as nation-state-centred power structures. Thranhardt and Bommes (2010) further substantiate this point by showing empirically how migration studies developed within distinct national context leading to the reification of distinct national models of integration/migration.

Where did this turn beyond methodological nationalism lead to? Several important trends can be defined in the literature. One involves the rise of perspectives that go beyond nation-states, such as transnationalist (Faist 2000, Vertovec 2009) and postnationalist (Soysal & Soyland, 1994) perspectives. Such perspectives have helped reveal how migration and migrant communities can also be shaped in ways that reach beyond nation-states, such as in transnational communities that connect communities from across various countries or in the notion of universal personhood that defines the position of migrants regardless of the state where they are from or where they reside.

Another perspective takes migration studies rather to the local (regional, urban, or neighbourhood) level of migration and diversity. Zapata-Barrero et al. speak in this regard of the local turn in migration studies (2010). They show how migration-related diversities take shape in specific local settings, such as cities or even neighbourhoods, in ways that cannot be understood from the traditional notion of distinct national models.

Also, in the study of migration itself, an important trend can be identified since the 2000s. Rather than focusing on migration as a phenomenon where someone leaves one country to settle in another, the so-called “mobility turn” (Boswell & Geddes, 2010) calls for a better comprehension of the variation in mobility patterns. This includes for instance variation in temporalities of migration (temporary, permanent, circular), but also in the frequency of migration, types of migration, etc. In this book we will address such mobilities in the forms of different types of migration, frequencies and temporalities by discussing very different migration forms.

3.5 Growing Self-Critical Reflection in Migration Studies

Since the 2000s, there has also been a growing reflexive and self-critical approach within migration studies. Studies like those of Wimmer and Glick-Schiller, Favell, and Dahinden are clear illustrations of this growing conceptual self-consciousness. The field of migration studies has itself become an object of critical reflection. In the context of this book, we take this as a signal of the coming of age of migration studies.

This critical reflection touches upon a variety of issues in the field. One is how the field has conceptualised ethnicity, which was criticised as “ethnic lensing” (Glick Schiller & Çağlar, 2009). This would involve an inherent tendency to connect and problematise a broad range of issues with ethnicity, such as studies on how ethnic communities do on the labour market or the role that ethnicity plays in policies. The core argument to move beyond ethnic lensing is that focusing only on ethnicity risks defying social complexity and the importance of intersectionalities between ethnicity and, for instance, class, citizenship, education, location, cultural, or political disposition, etc. Dahinden (2016) calls in this context for a “de-migrantisation” of migration studies to avoid the naturalisation of migrants in relation to all sorts of issues and problems. Vertovec (2007) develops the concept “super-diversity” in this context to capture the social complexity of migration-related diversities.

Another strand of critical reflection concerns the field’s relationship to policymaking. Studies like those by Scholten et al. (2015) and Ruhs et al. (2019) offer critical reflection on the role that the relationship between migration studies and broader policy settings has played in the conceptual and methodological development of the field. On the one hand, the evolution of the field has been spurred on in its policy relevance, for instance in research on migration management or ‘migrant integration’. This relationship has contributed to the co-production of knowledge and key concepts, such as ‘integration’, and impeded the critical and independent development of the field. On the other hand, the field also leaves important gaps in research-policy relations, leaving important areas of knowledge production hardly connected to knowledge utilisation. Such studies have raised awareness of the necessity of research-policy relations for the societal impact of the field, while also problematising the nature of research-policy relations and their impact on the development of the field itself.

Finally, also in the context of growing public awareness on racism, the field has increasingly become self-reflexive in terms of how it deals with issues of discrimination and racism. This includes a growing awareness of institutional racism in the field itself, such as in institutes or training programs. Besides contributing to the broader field, there has been an increase of instances where institutes revise their own management and procedures in order to enhance racial justice. This includes participation of scholars from the global south, but also a proliferation of diversity policies in the field. At the same time, criticism remains on the extent to which the field has acknowledged issues of racial justice, for instance in studies on integration, migration management, or social cohesion.

4 Mapping Migration Studies Today

4.1 Co-Citation Communities

Nowadays, migration studies has become a more interdisciplinary field. In the last 15 years, as the “embryo” development in Fig. 1.4 shows, it became more oval-shaped without sharp “tails”. This form indicates a cross-disciplinary osmosis; a growing interlinkage of epistemic communities. Co-referencing of authors from different disciplinary orientations became more common in the twenty-first century. Such developments can be attributed, on one hand, to the rapid digitisation of libraries and journals, as well as the multiplication of migration-focused journals, which accepted relevant contributions to discussion on migration, no matter the discipline. On the other hand, interdisciplinary endeavours were encouraged externally, for instance via grants (see European Union, 2016) and interdisciplinary master programmes created in various universities. It became fashionable to work at the intersection of disciplines, to an extent that nowadays it is often difficult to determine the disciplinary origin of a publication about migration. Whether such developments have yielded any theoretical or empirical breakthroughs is yet to be seen. In any case, it is clear that migration studies moved from being a multi-disciplinary field (with few connections between them) to an interdisciplinary field (with more connections between multiple disciplines) (Levy et al., 2020).

Let us now dive into the most recent co-citation clusters. Such clusters are, of course, not only categorised in terms of disciplines. They also have certain topical focuses. Figure 1.6 below zooms in to the data from Fig. 1.4 and shows the co-citation network in the period 2005–2014 in more detail. We can see seven different groups of migration scholarship that are nevertheless rather interlinked, as the oval shape of the network indicates. At 1 o’clock we can see the cluster we have elsewhere called the “Global systems school”, which has developed around such scholars as Vertovec, Soysal, Levitt, Favell, Faist, and Glick-Schiller, who introduced and developed the concept of transnationalism since the late 1990s. Contrasting with longstanding conventions of looking at migration as having an ‘endpoint’ in the countries of reception, they developed a different view of migration as a global, on-going, and dynamic process impacting receiving as well as sending societies, along with the identities, belonging, and ‘sense of home’ of migrants themselves. Nowadays, this cluster includes a very diverse group of scholars with different thematic focuses, such as the migration-development nexus (see also Chap. 18, this volume) including de Haas, Carling, and Castles; prominent scholars on Asian migration, such as Ong and Yeoh; and many others, Guarnizo, King, Anderson, Sassen, Joppke and Baubock. Yet, the fact that they all belong to one cluster, proves that their work has been cited in the same reference lists, thus constituting an interlinked conversation on migration as global phenomenon.

Fig. 1.6
An image of the co-citation map. The different citation topics are highlighted such as mobilities, ethnic or race relations, race, migration, health, economics, sociology, and demography.

Co-citation map of authors with 10+ citations in migration research in the period 2005–2014. (From Levy et al. 2020, p. 17)

Closer to the centre of the network, we find a blue cluster, centred around Portes, a widely-cited founding father of migration studies in the USA. Next to him we also see other leading American scholars such as Waldinger, Alba and Zhou, Waters, Rumbaut, and Putnam, whose primary concern is the (economic) integration of immigrants. This cluster of scholars has elsewhere been understood as the “Michigan-Wisconsin” school of migration research, given the two universities’ success in training migration scholars in the US (cf. Hollifield, 2020). Traditionally this scholarship has developed in the USA and has been very prominent in the field for decades. Especially Portes is cited extensively, and widely co-cited across the epistemic communities of the whole field.

This cluster is closely interlinked with the neighbouring (at 4 o’clock) cluster of economists, demographers, and other quantitative social scientists (turquoise). At the centre of it is Massey, another giant of migration studies, who mainly conducted his migration research from a demographic perspective. Here we also see economists such as Borjas, Chiswick, and Stark, who predominantly studied the immigration reality of the USA.

Then, at 6 o’clock, we see a light-green cluster. The highly cited scholars in its core are Williams and Krieger, who study migration- and race-related differences in health. For instance, Williams’ highly-cited paper is about the experiences of racism and mental health problems of African Americans, while Krieger investigated how racism and discrimination causes high-blood pressure. Health is one of the ‘younger’ topics in contemporary migration studies; the amount of research on the intersection of migration and health has increased significantly in the last decade (Pisarevskaya et al., 2019).

Closely interlinked with ‘health’ is the cluster of ‘acculturationists’, positioned at 7 o’clock. The cluster is formed around J.W. Berry, a social-psychologist who introduced a theory of immigrant acculturation (1997). Scholars in this cluster investigate cross-cultural and intercultural communication from the psychological perspective. Other prominent authors in this cluster include Phinney, Pettigrew, Ward and Tajfel who studied cognitive aspects of prejudice, and Stephan famous for their integrated threat theory of prejudice (Stephan & Stephan, 2000).

Another significant group of scholars is positioned between 9 and 12 o’clock of the co-citation network. These are scholars focused on the politics of ethnic and race relations; prominent critical sociologists such as Foucault and Bourdieu are frequently co-cited in this cluster. Among the key authors in this group are Hall, Gilroy, Brubaker, Kymlicka, Asante, Du Bois, and Bonilla-Silva.

At 12 o’clock, we can see an orange cluster, positioned between the ethnic/race relations cluster and the “Global systems school” – this is a relatively new cluster of scholars working on the topic of mobility, developed by Urry, Scheller, and T. Cresswell. Other researchers within this loosely connected cluster focus in their research on mobilities from related to work and studies from the perspective of social and economic geography. The focus on mobility has been on the rise; it entered top three most prominent topics in migration studies in the period 2008–2017 (Pisarevskaya et al., 2019).

Overall, in the twenty-first century, the scholarship of migration in its variety of approaches and intertwined themes has seemed to move away from “‘who’- and ‘what’- questions, to ‘how’- and ‘why’-questions”, compared to the early days of this field. Efforts towards quantifying and tracing geographies of migration flows and describing migrant populations in the receiving countries have somewhat declined in academic publications, while research on the subjective experiences of migrants, perceptions of migrants’ identity and belonging, as well as attention to the cultural (super)diversity of societies has become more prominent (ibid.).

4.2 Internationalisation

Since migration is a global phenomenon, it is important that it is studied in different countries and regions, by scholars with different academic and personal backgrounds, as well as for knowledge to be transferred around the world. Only by bringing together the diversity of perspectives and contexts in which migration is studied we can achieve a truly global and nuanced understanding of migration, its causes, and its consequences.

Over the course of the field’s development, migration studies has internationalised. Even though analysis of internationalisation trends has only been conducted on English-language literature, the trends seem to be rather coherent. The number of the countries producing publications on migration has increased from 47 to 104 in the past 20 years. Publications from non-Anglophone European countries have increased by 15%, to constitute by today almost a third of English-language publications on migration, while the relative share of developed Anglophone countries (USA, UK, Canada, Australia) has declined (Pisarevskaya et al., 2019). The proportion of migration research that is internationally co-authored has also increased over the past 20 years, from 5% of articles in 1998 to over 20% in 2018 (Levy et al., 2020).

Nevertheless, international collaboration is not equally spread across the world. European and North American migration scholars have produced the highest absolute number of international collaborations between 1998 and 2018, though the relative share of collaborations among Europe-based scholars is much higher (36%) than that of their North American colleagues (15%). The suggested reasons behind these trends could be that critiques of national paradigms in migration studies have been taken up in Europe more eagerly than in North America. This has not happened without facilitation by broader science policies, particularly in the European Union, which funded the creation of the IMISCOE Network of Excellence, a network which intensified international collaborations between the research institutes working on migration and integration issues in various European countries.

In the global south, similar initiatives have been established, such as the Network for Migration Research on Africa and the Asia Pacific Knowledge Network on Migration. In these regions, international co-authorships are not uncommon, but the absolute number of publications in English compared to those from the north is small. We have thus observed an “uneven internationalisation” of migration studies (Levy et al., 2020); in the case of the gender and migration nexus, for instance, Kofman (2020) argues that the concentration of institutions and publishers in migration studies headquartered in the north perpetuates such inequalities.

5 An Outlook on This Interactive Guide to Migration Studies

This book is structured so as to provide an overview of key topics within the pluralist field of migration studies. It is not structured according to specific theories or disciplines, but along topics, such as why and how people migrate, what forms of migration are there, what the consequences of migration are, and how migration can be governed. Per topic, it brings an overview of key concepts and theories as well as illustrations of how these help to understand concrete empirical cases. After each chapter, the reader will have a first overview of the plurality of perspectives developed in migration studies on a specific theme as well as first grasp of empirical case studies.

The book is designed as an ‘interactive guide’; it will help connect readers to readings, projects, and reports for the selected themes via interactive links. To this aim, the book outline largely follows the official taxonomy of migration studies at migrationresearch.com. Throughout the text, there will be interactive links to overview pages on the Migration Research Hub, as well as to specific key readings. This marks the book as a point of entry for readers to get to know the field of migration studies.