The study of irregular migration as a specific social phenomenon took off during the 70s in the US. Since then, the academic interest has continually grown and spread, first to Europe and, in the last years, to other regions worldwide. This interest can certainly be related to the increasing attention paid to the study of migrations more in general (Castles & Miller, 1993). The trend can be linked to those broad and complex social and economic changes, often subsumed under the concept of globalization. The specific focus on irregular migration, though gaining momentum throughout the 1980s, reached preeminent attention in the 1990s. On both sides of the Atlantic, the explosion of the so-called “migration crisis” (Zolberg & Benda, 2001) and the emergence of irregular migration as a widespread social fact raised the attention of public opinion and academics alike. Moreover, in recent years, what seemed at first to be an issue concerning only the high-income regions of the planet, now involves also medium and low-income ones, making irregular migration a truly global structural phenomenon (Cvajner & Sciortino, 2010a; Düvell, 2006).

Accordingly, after a lapse of two decades, a topic that for a long time had been relatively marginal (Anderson & Ruhs, 2010; Bloch & Chimienti, 2011) became the object of numerous studies and of a consistent and diversified literature. Given the complexity of the phenomenon, its multiple dimensions, and levels of social interaction, its study has inevitably taken a multidisciplinary path. The literature has rapidly expanded in many directions and, today, irregular migration constitutes an important subfield within migration studies.

This chapter will present a general overview of the main directions and developments that the research on irregular migration has taken. Even if some scholars have lamented a limited cumulative effort, many studies are available and it is now possible to refer to them as a solid starting point for analysis. To avoid getting trapped in difficult and sometimes redundant disciplinary distinctions, this overview will focus on the key issues that have been researched from different perspectives. In this respect, it seems possible to identify six main general thematic fields.

1 Definition and Taxonomies

Since migration is a complex and multifaceted social phenomenon, an important and on-going debate has focused on terminology issues. Many terms and definitions have been proposed: irregular, illegal, undocumented, clandestine, unauthorized, informal, unregistered, sans papier, etc. (Baldwin-Edwards & Kraler, 2009; Düvell, 2006; Jordan & Düvell, 2002; Triandafyllidou, 2009; Vasta, 2011). Each of these has a different focus or emphasis, as well as some advantages and problems.

As pointed out by Nicholas De Genova, the choice of a term does not occur in a social vacuum and it is not politically neutral, for this reason, it should therefore not be taken uncritically (De Genova, 2002). In fact, within a field that has become increasingly politicized, it is not surprising that the selection of terms has assumed a contested nature (Anderson & Ruhs, 2010). Researchers have had to deal not only with classic epistemological problems of definition and perspective but also with the social meaning and connotations that the different terms have in specific contexts. Especially in the last decade, this issue has become increasingly problematic. A number of negative social myths and stereotypical images, usually associated with crime (Castles, 2010; Coutin, 2005b; Dal Lago, 2004; Koser, 2010), have been connected to irregular migration in the public debate and media (Van Der Leun, 2003; Van Meeteren, 2010). Perhaps the most heated dispute has surrounded the use of the term “illegal migration”. On the one hand, some scholars have considered that the use of this term contributes to the negative social myths (Koser, 2010; Schrover, Van Der Leun, Lucassen, & Quispel, 2008) and has a criminalizing effect (Düvell, 2006). In a similar fashion, others have stated that its use is simply incorrect since an act can be illegal, whereas a person cannot be so (Castles, 2010; Schinkel 2005 in Engbersen & Broeders, 2009). On the other hand, some scholars have alleged that the term must be used, but in a critical way. From this perspective, it is precisely the process of social and political construction of “illegality” and its consequences that needs to be researched, in particular, the way in which migrants become “illegal migrants” (De Genova, 2004; Willen, 2007).

Behind this terminological debate, there is hidden a related, more substantial one, which is conceptual. Whatever term is adopted, two questions need to be addressed: (a) to what phenomenon does it refer?; (b) from whose perspective?

A certain but far from unanimous consensus has been reached about the fact that the term should refer to the relations between a migrant and a set of rules established by the state, and not to a migrant him/herself (De Genova, 2002). Irregular migration would then be the outcome of the interaction between human mobility across social spaces and the enactment of policies within those very same spaces. In this sense, “the adjective, irregular, does not belong to the domain of description of the migration flows, but only to their interactions with political regulations” (Sciortino, 2004b, p. 21). The complexity of the first question becomes evident once it is recognized that there are many possible types, degrees and dimensions of irregularity (Baldwin-Edwards & Kraler, 2009; Broeders & Engbersen, 2007; Düvell, 2011c; İçduygu, 2007; Triandafyllidou, 2009; Williams & Windebank, 1998).

The term, in fact, can refer to migrants’ non-compliance with the rules of entry, residence, employment or a combination of these (Van Der Leun, 2003; Van Meeteren, 2010); to a number of legal statuses implying very different social and economic conditions (Chavez, 1991; Massey et al., 1998; Van Nieuwenhuyze, 2009); and to different forms of social stratification and hierarchy (Castles, 2004; Cvajner & Sciortino, 2010b; López Sala, 2005; Sciortino, 2013; Vasta, 2011). Status, moreover, is not as clear-cut as one might expect, and there is room for forms of legal ambivalence, semi-legality, legal illegality, and formal informality (Düvell, 2011b). Furthermore, “behind the notion of irregular migration there is today a set of interpretative frames, stereotypes, folk wisdom, icons and slogans that makes it a part of a complex symbolic discourse” (Cvajner & Sciortino, 2010b, p. 390). Finally, “the meaning of irregularity shifts across time and space, it is a fluid construction” (Schrover et al., 2008, p. 10); “It is not an “on-off” condition, but rather a bundle of statuses variously significant in different contexts” (Ruhs & Anderson 2006 in Bommes & Sciortino, 2011, p. 219). Depending on where migrants are, they can move in and out of irregularity (Reyneri, 1998), in different ways (Van Der Leun, 2003), for longer or shorter periods. States, on their side, can turn irregular migrants into legal foreign residents, or the other way around “with the single stroke of a pen” (Sciortino, 2013).

In an attempt to organize this diversity of possibilities, once the aspiration for a clear-cut, yes or no, all-embracing definition was abandoned, two main paths have been followed. The first has aimed to develop more flexible definitions, in order to see irregularity not as a fixed status but as a process (Bloch & Chimienti, 2011; Castles, 2010; Jordan & Düvell, 2002). From this perspective, it has been proposed to go beyond the illegal/legal divide and, instead, to understand irregularity as a particular set of conditions within a continuum between two ideal types. On the one hand, there is the “total irregular” (entry, residence, work, illegal practices) and, on the other, “the perfect citizen”, somewhere in between all the different cases of “semi-compliant” migrants (Bridget Anderson & Ruhs, 2010). In a similar fashion, irregularity has been defined as an “in-between state among regularisability and deportability” (Garcés-Mascareñas, 2012).

The second path has been to develop taxonomies of different types of irregularity (Bloch & Chimienti, 2011; Haidinger, 2007). Many criteria have been used: ways into irregularity (irregular border-crossing, visa overstaying, refused asylum-demand, violation of the obligation to leave the territory, ineffective deportation, bureaucratic failure/befallen irregularity, birth from irregular parents); duration of stay (limited-, circular- or settlement-irregular migration); types of law violation (irregular entry, residence or work); channels and motivations (smuggled, trafficked, voluntary or forced irregular migrations); irregular migration composition (family, refugees or labour irregular migrations) (Düvell, 2011b; Koser, 2010; Sciortino, 2004b; Vogel & Cyrus, 2008). Regarding the different ways in and out of irregularity and, in order to capture the diversity of possibilities, what has recently been proposed is the distinction among geographical or migration flows, demographic flows and status-related flows (Kraler & Reichel, 2011).

The choice of a certain term implies also the adoption of a specific point of view and of a certain “subjective” perspective. Though this is inevitable, it is important to bear it in mind at every stage. From this perspective, it is possible to distinguish between both taxonomies from above (i.e. the state’s point of view) and from below (i.e. the migrant’s point of view) (Bloch & Chimienti, 2011). Many scholars have discussed how the term illegal migration entails the adoption of the point of view of the state, which tends to interpret the phenomenon as problematic and challenging (Frank 2008 in Anderson & Ruhs, 2010). This point echoes a more general epistemological and methodological critique of what has been defined as “methodological nationalism” (Castles, 2010; Mezzadra, 2011; Wimmer & Glick-Schiller, 2003). The uncritical adoption of a terminology developed within a statist paradigm, it is argued, leads to distorted representations and to the misperception of a “constructed reality” as if it were the natural one. In this regard, it is important not to forget that much of the terminology used to address issues relating to migration has been developed by state administrations in order to deal with these very issues. Van der Leun, recalling the work of Scott, has warned against those “state simplifications” that are produced and continuously refined to classify migrants (Scott, 1998; Van Der Leun, 2003).

An interesting distinction that the term illegal is unable to capture is the one between what is considered legitimate by the state (“legal”) and what is legitimate for people (“licit”). Many trans-border movements of people are illegal because they defy authority, but they are quite acceptable, “licit”, in the eyes of participants. Since the state controls those who occupy, use or cross its territory, individuals who contest or bypass controls are bringing into discussion the legitimacy of the state, by questioning its ability to control its territory (Schrover et al., 2008). This example shows the possible conflict between the legal and the political terminologies. Furthermore, if it is considered that, in every national context different legal and political cultures, ideas of national identity, and perceptions of migration are at work (Boswell & D’Amato, 2012; Düvell, 2011b; Kraler & Rogoz, 2011), a full picture of the complexity surrounding the definition and social meaning of irregular migration becomes evident.

The term that has been chosen for this study is irregular migration. Even if this term is not free from possible critiques, its extensive use, especially in the European literature, its flexibility and its relatively neutral perspective make it a suitable tool.

2 Irregular Migration from an Historical Perspective

Even if the interest surrounding irregular migration was only aroused in the 1970s, the phenomenon certainly did not appear then. An important line of research has investigated the historic origins and evolution of irregular migration. This task has produced two main types of research. On the one hand, there have been more general accounts on the origin, evolution and trends of irregular migration (Garcés-Mascareñas, 2012; Hollifield, 2004; Schrover et al., 2008; Sciortino, 2004b; Torpey, 1998). On the other, there have been more specific, case-centred studies that enquired into the reasons, ways and moments in which irregular migration appeared in different regions or countries throughout the world. These efforts led to the development of specific national studies and, to a lesser extent, in recent years, to a number of international comparative studies.

If irregular migration is the result of the interaction between migrations and state enforcement of controls over migrants, the history of irregular migration “coincides with the history of attempts by states to gain control over the composition of their population” (Sciortino, 2013). It was the attempt by states to “monopolize the legitimate means of movement” (Torpey, 1998) that made irregular migration emerge as a correlated by-product. Yet, if it is true that, as Sciortino citing Paul of Tarsus has pointed out, “where there is no law, there is no violation” (Sciortino, 2013) it is also true that the existence of a law does not automatically imply its violation. In this sense, the history of irregular migration is not simply the story of migration controls and their implementation, but the story of the interplay of the latter with actual migrants. From this perspective, although the conflict between controls and migrations occurred in a differentiated manner throughout history and geography, and even today there is not one single picture, four broad historical phases seem to be discernible.

The first phase goes from the moment in which nation-states started to coalesce as the main form of political organization, in the sixteenth century, to World War I. This period was mostly marked by weak controls and unrestricted migrations. The old forms of political, territorial and population control were slowly transformed into new, statist ones. National borders became more important than other territorial boundaries, such as the municipal ones (Fahremeir 2007 in Schrover et al., 2008). The process was driven by the diffusion of nationalist ideologies and the idea that a specific population corresponds to each state. Along these lines, states started to develop both legal and administrative mechanisms to register and control their populations, to regulate their borders, and to manage foreign populations (Torpey, 1998). Although instruments to control the movement of vagrants, poor foreigners or unwanted populations (for ethnic, racial or religious reasons) had previously existed at a local level in many contexts (Schrover et al., 2008; Sciortino, 2013, 2017; Zolberg, 2003), “the idea that spatial movements should be considered primarily in terms of their having complied, or failed to comply, with a certain set of generalized, abstract regulations” emerged only at this time (Sciortino, 2013).

Nevertheless, the effective ability to enforce this idea was slowly and unevenly accomplished (Torpey, 1998). For a long time, the ability of state to “effectively control the legitimate means of movement” was still in an embryonic phase. At the same time, although its characterization as a laissez-faire era is certainly overstated, this period can still be considered one of relative openness. The point is not that there were no controls or restrictions at all, but that, since there was a certain equilibrium between the need of migrants in certain societies and overpopulation in others (Hollifield, 2004; Torpey, 2000), migrations were habitually welcomed. The combination of these two circumstances, the embryonic condition of immigration controls and the welcoming character of immigration fluxes made irregular migration quite a marginal if not negligible phenomenon (Hollifield, 2004).

The second phase corresponds approximately to the interwar period. This phase can be regarded as one of increased controls and limited unwanted migrations. States came close to realizing “the bureaucratic fantasy of achieving total control over society” (Ronsenberg, 2006, p. 7 in Schrover et al., 2008). Both their ability and aspiration to control populations were prompted by a number of factors. On the one hand, the material possibilities of states increased thanks to the technological and economic improvements brought by scientific and industrial revolutions. This led to the creation of large and effective bureaucracies capable of regulating and conditioning most social transactions (Garcés-Mascareñas, 2012). The identification and registration of populations were seen as the first steps in order to be able to “read” societies, “embrace” them and make surveillance effective (Broeders, 2009; Scott, 1998; Torpey, 1998). By the 1920s, “the legal and administrative apparatus able to distinguish between citizens and foreigners and, within the latter category, between lawful and unlawful residents” (Sciortino, 2013, p. 6) had become widespread. In this sense, “the urge to control became the ability to control” (Schrover et al., 2008, p. 16).

On the other hand, this period was characterized by the strong affirmation of nationalism, often conflated with racist and xenophobic ideas (Brubaker, 1992; Hobsbawm, 2012). The main consequence was a restrictive turn against migrations that was firstly enacted by the US (Ngai, 2014) and then by most of the other receiving countries (Baldwin-Edwards, 2008; Lucassen & Lucassen, 2005; Schrover et al., 2008). This second period saw the concomitant rise of controls and a decrease in international migration. Whereas the two factors are certainly related, the reduction of international fluxes also had other explanations, mostly related to the changed conditions in the sending countries. In this context of increased control-competency and diminished migratory pressures, irregular migration remained a minor phenomenon.

The third period goes from the end of World War II to the 1970s. This phase can be characterized by a further increase in the control capacity of states, accompanied, however, by a high demand for foreigners. In the aftermath of the war, the demand for workers rapidly increased in Northern European countries and in the US. As pointed out by Baldwin-Edwards, the types of migration varied according to historical, cultural and geographical parameters. The classic immigration settler societies chose permanent immigration over labour migration; postcolonial countries opted for inflows of their colonial citizens; other countries, like Germany, Austria, Switzerland and Belgium, relied on temporary labour schemes (Baldwin-Edwards, 2008). While this categorization describes preponderant patterns, most countries combined strategies and shared the illusion of “migration management” (Garcés-Mascareñas, 2012; Ngai, 2014). Since the priority was to fulfil the demands of a booming economy, those migrants that were able to enter the countries irregularly and found employment were usually and tacitly regularized. Thus, irregular migration was not considered a major problem but rather a transitional phase in the path of migrants. “Expulsion, albeit formally a generalized sanction for irregularity, was mainly interpreted factually as a selective measure to deal with foreign misfits and troublemakers” (Sciortino, 2013, p. 6).

The fourth period goes from the 1970s to our days. Increasingly conflictive relations between receiving states and migratory pressures have characterized this phase. The combination of powerful control systems and masses of migrants willing to travel and, finally, able to do so, set the conditions for irregular migration to become a widespread and sizable phenomenon in unprecedented terms. This explains the vast attention that this period has received and the production of an extensive literature. Scholars have widely discussed the complex structural changes that have occurred in industrialized countries since the mid-1970s. These changes, often referred to as “the end of Fordism”, “the rise of the post-industrial economy”, or “the economic restructuring” have greatly affected the productive organization, the labour-market structure, and labour relations in the receiving societies (McNevin, 2009; Mezzadra, 2011; Morokvasic, 1993; Piore, 1980; Sassen, 1996; Schierup, Hansen, & Castles, 2006; Wallerstein, 2004).

The impact of these changes has had a long-term effect on the approach to migration and on its management. The turning point was the 1973 oil crisis which implied the abrupt end of the recruitment programmes and the setback of the tolerant and flexible attitude towards irregularity (Engbersen & Van Der Leun, 2001; Zolberg, 2003). It was at this point that the unintended effects of migration policy became manifest, with migration increasingly dealt with as a problem rather than as a resource (Arango, 2005; Broeders, 2009; Sciortino, 2000; Van Meeteren, 2010). The idea that migrants could be used as a commodity in the productive process proved false. Migrants had no intention to return to their countries of origin. Moreover, they had acquired a full set of rights that entitled them to benefit from welfare state provisions, to reunify their families, and to eventually become citizens. Besides, they had developed their own businesses and networks. All this implied that, once started, migrations displayed a self-sustaining dynamic, largely independent from political decisions (Massey, 1999). “The response to this perceived threat has been a building up of visible and invisible walls” (Garcés-Mascareñas, 2012, p. 23). The goal was not only to prevent new entries but also to shelter the welfare state and make access to rights increasingly complicated. As mentioned, the idea that states had lost control over migration became popular both among politicians and the public opinion and started to produce long-lasting effects. Consequently, despite the economic recovery and the renewed demand for migrant labour in the years to follow, the restrictive attitude was maintained.

The 1970s’ economic crisis did not only affect the so-called developed societies. Its causes and effects have also been seen as part of broader processes of economic and political change that have had a global reach. It is precisely in these processes that researchers have found the roots of globalization and, regarding the international flux of people, the beginning of the “age of migrations” (Castles & Miller, 1993). A number of socio-economic transformations have been analysed from different perspectives: the economic restructuring of peripheral economies and the imposition of a neoliberal agenda by the FMI (McNevin, 2009; Mezzadra, 2011; Sassen, 1998; Schierup et al., 2006); the geopolitical shift after the end of the Cold War and the fall of exit barriers in most countries (Massey, 1999; McNevin, 2009); the out-burst of ethno-national conflicts (Zolberg, 2006); the emergence of transnationalism (Glick-Schiller, Basch, & Blanc-Szanton, 1992); the flexibilization, delocalization and internationalization of productive processes (Schierup et al., 2006); and the development of transportation and communication technologies (Castles & Miller, 1993). As a matter of fact, one of the most significant effects of these complex transformations was the great incentive towards international migrations.

The combination of restrictive policies and sustained demand for labour on the one hand, and of a potentially unlimited supply of migrants on the other, set the conditions for what has been called the “migration crisis” of the 1990s (Castles, 2004). Since these two forces could not match by using the legal channels established by states, alternative strategies quickly developed. Irregular crossing of borders, visa overstaying, the improper use of asylum policy, just to name the most important, became widely used channels to circumvent the states’ barriers. Thus, irregular migration emerged as a structural characteristic of current migration processes.

This “unexpected” outcome sharply increased concerns in receiving societies, paving the way for widespread social attention, the anxiety of public opinion and a rapid politicization (Castles, 2004; Vollmer, 2011; Zolberg, 2006). Governments reacted by prioritizing migration policies in their agendas and the main target was precisely irregularity. The result was a multiplication of policies, mechanisms, and investments both at national and international levels, in an attempt to regain control over migration. These extraordinary efforts, nevertheless, have been largely wiped out by counterstrategies enacted by migrants and by those interested in the continuation of the fluxes. These dynamics between states and migrants have been compared to an arms race in which action provokes reaction (Broeders & Engbersen, 2007). The most notable effect of these dynamics has been the diversification of the characteristics and modes of irregularity (Bloch & Chimienti, 2011).

3 Numbers

One of the most difficult tasks regarding the study of irregular migration has been assessing the magnitude of the phenomenon. It is precisely its irregular character that provides the reasons for such difficulties. If a certain elusiveness of their objects is an inevitable problem for social sciences, this issue becomes even more complex when the object in question is defined as “irregular”. Contrary to what occurs with the majority of other social phenomena, with irregular migration it is not possible to count on official statistics. The ways in and out of irregularity are many and available data are limited to only a part of these fluxes.

At the same time, the politicization and social anxieties that have surrounded irregular migration have been a powerful reason for both administrations and public opinion to ask for numbers. After all, in order to assess the extent of a threat, it is firstly necessary to know its magnitude. This has implied the proliferation of analyses, journalistic reports, and official and unofficial estimations. The sensitive aspect of the topic, especially for states that, on the basis of those numbers, could be publically judged as either efficient or inadequate, entailed an inevitable tendency to manipulation (Dal Lago, 2004; Vollmer, 2011). Numbers have often been exaggerated, minimized, hidden or dramatized, depending on the political goal behind their use. In this respect, Vollmer has underlined the relevance of “number games” in the construction of political discourses about irregular migration (Vollmer, 2011).

The complexities related to the estimations of irregular migration and to their use have raised an interesting scientific debate as to their utility. Some scholars have argued against the proliferation of statistics, by stressing the methodological pitfalls and the political misuse of numbers (Koser, 2010; Triandafyllidou, 2012). Others, on the contrary, have emphasized the necessity for the collection of valuable data (Düvell, 2011b; Koser, 2010). More specific debates have developed around the methodological (Espenshade, 1995; Jandl, 2011; Koser, 2010; Triandafyllidou, 2009) and ethical problems related to the use of statistics (Düvell, Triandafyllidou, & Vollmer, 2010; Triandafyllidou, 2009).

Kraler and Reichel have recently stressed that irregular migration estimations and numeric analysis “can be useful for assessing broad trends regarding the dynamics, patterns, as well as structure of irregular migration” (Kraler & Reichel, 2011, p. 121). While it is true that precise numbers are not attainable and that their use is permanently at risk of political mistreatment, the recent proliferation of estimations of the irregular population in different national contexts is certainly welcomed. For a discussion on general trends and the numerical relevance of irregular migration see, for instance: (Castles, 2010; Düvell, 2011c; Kraler & Reichel, 2011; Triandafyllidou, 2009; Vogel, Kovacheva, & Prescott, 2011). For specific reports by country, see: (Passel, Cohn, & Gonzalez-Barrera, 2013; Triandafyllidou, 2009).

4 State Policies and Irregular Migration

As a by-product of the interaction between states and migrations, one important strand of research has focused on the study of those policies that directly or indirectly affect irregular migration. The attention to policies is relatively recent and can be linked to the inability of scholars to fully explain the migration crisis at the end of the twentieth century, using their classic tools. The combination of push-pull theories, agent’s microeconomic theories and network theories had been fairly successful in describing migration mechanisms, at least as they occurred in accordance to state will. After the oil crisis of the 1970s, and increasingly throughout the 1980s, theoretical efforts were made to interpret the new setting (Massey et al., 1998). Only in the 1990s, however, did the study of the role of the state become central for migration studies (Massey, 1999; Zolberg, 2000). Since then, a vast and diverse literature has emerged. Most of this work has either implicitly or explicitly dealt with irregular migration. Irregularity, being a sort of nemesis of state policies, has been one of the main targets and somehow the measure of the failure and success of these policies. The consolidation of irregularity as a structural phenomenon in all receiving societies, exactly at a time when major efforts were being made to control migration, raised a number of questions. Were states losing control of their borders and populations? Were there hidden interests that secretly favoured irregular migration? How could policies be improved in order to successfully deter unwanted migrants? In relation to these questions, the study of policies and their evolution appeared as a crucial step in order to understand the opportunity structure within which irregular migration emerges and develops as a social phenomenon.

The research on policies has dealt with four main questions: (a) how and by whom are policies decided?; (b) What are the main types?; (c) How are they implemented? (d) Why do they fail? This chapter will analyse the debate around the first three questions; the fourth will be one of the main topics of Chap. 3.

4.1 Policy Formation

A first important issue scholars had to deal with concerned the production of migration policies. Two questions appeared critical: how are policies decided and in which arenas? What actors, forces and interests concur to their configuration? These questions are extremely relevant to the discussion on irregular migration. In order to understand to what extent irregularity is the result of a deliberate policy or not, it becomes crucial to identify what interests have favoured its formulation.

Regarding the relevant actors and ideas, a variety of hypotheses have been proposed. The discussion has generally followed general sociological- and political-science theories on policy formation. Some scholars have emphasized the role of domestic political factors, such as: national identities and cultures (Düvell, 2011b; Freeman, 1995; Jordan, Stråth, & Triandafyllidou, 2003), conception of citizenship (Brubaker, 1992), and migratory history (Arango, 2003; Massey et al., 1998; Zolberg, 2006). Others have focused on the role of domestic actors, for instance: employers, labour unions, interest groups, courts, ethnic groups, trade unions, law and order bureaucracies, police and security agencies, local actors and street-level bureaucrats, and private actors (Abella, 2004; Freeman, 1995; Lahav & Guiraudon, 2006; Piore, 1980; Portes, 1978). In this respect, Czaika and de Haas have stressed that, since migration policy is typically the result of a compromise between multiple potentially-competing interests, it can be useful to pay attention to the “discursive coalitions” that may form (Czaika & De Haas, 2013). Another important branch of research has underlined the relevance of legal frameworks, political institutions and their functioning in establishing the procedures and limits of the bargaining around migration policy (Freeman, 1995; Hollifield, 1992; Joppke, 1998; Lahav & Guiraudon, 2006; Money, 1999; Shughart, William, Tollison, & Kimenyi, 1986). Another has focused on the interests of states as sovereign and self-preserving actors (Rudolph, 2005). Finally, many scholars have focused their attention on the role of forces external to states. Within this line of enquiry, what has been emphasized is the role of the global economy (Sassen, 1998; Wallerstein, 2004), of human rights regimes (Jacobson, 1996; Soysal, 1994), and of international legal frameworks and institutions (for instance the EU) (Geddes, 2001, 2003). For a more detailed analysis of these traditions, a number of review essays on immigration policies provide a wide analytical panorama of them (Meyers, 2000; Money, 2010).

Once the existence of a variety of actors and of frequently-irreconcilable interests has been recognized, attention has shifted to the decision process. In relation to this, different positions have emerged on the role of the state. Garcés-Mascareñas has highlighted two main perspectives: theories that consider states mainly as brokers of civil-society demands (Freeman, 1995) and theories that consider states and their interests as the main force behind migration decisions (Garcés-Mascareñas, 2012; Rudolph, 2005). Within this debate, attempts to produce more complex accounts of state imperatives and functioning have been advanced (Boswell, 2007; Lahav & Guiraudon, 2006; Sciortino, 2000). These efforts will be discussed in detail in Chap. 4.

4.2 Policies that Affect Irregular Migration

The study of the policies that affect irregular migration has gone hand in hand with their development. After the oil crisis of 1973, most receiving countries observed a proliferation of policies, mechanisms, administrative structures, and legal frameworks dedicated to dealing with the control of international migrations. The real or perceived sense of failure signalled by the migration crisis of the 1990s intensified the development and implementation of newer and increasingly-sophisticated policies. This perpetual escalation of control measures, on the one hand, and migrants’ countermeasures on the other, is far from being concluded in our days. The main consequence for research has been a corresponding proliferation of studies, taxonomies and classifications in the attempt to analyse a constantly evolving landscape. The remainder of this section proposes a classification and a brief description of the main policies that affect irregular migration. It is important to mention that, although the hypothesis of an on-going convergence among state practices has been advanced (Cornelius, Martin, & Hollifield, 1994; Doomernik & Jandl, 2008), national approaches still present important differences. Therefore, each state displays a different combination of policies and a peculiar trend of implementation (Castles & Miller, 1993; de Haas, Natter, & Vezzoli, 2018; Düvell, 2011b; Freeman, 2006; Lahav & Guiraudon, 2006).

A first important distinction in classifying migration policies is the one proposed by Hammar (1985) between immigration policy and immigrant policy (Hammar, 1985). Immigration policies include those directed at controlling and selecting or deterring migration fluxes. Within this broad group, two main sub-groups can be distinguished: external control policies and internal control policies (Brochmann & Hammar, 1999; Broeders & Engbersen, 2007; Cornelius, 2005; Cornelius et al., 1994; Doomernik & Jandl, 2008; Van Meeteren, 2010). The first group includes: border enforcement policies (Cornelius & Salehyan, 2007); remote control policies, such as carrier sanctions, international and bilateral agreements, visa regimes and entry policies (Finotelli, 2009; Finotelli & Sciortino, 2013; Garcés-Mascareñas, 2012; Guiraudon & Joppke, 2001; Massey, Durand, & Pren, 2015; Triandafyllidou, 2009; Triandafyllidou & Ambrosini, 2011; Zolberg, 2000, 2006); and policies aimed at reducing push factors in sending countries (for instance, funds for development) (Hollifield, 2004). The second group includes three main sub-groups: (a) policies directed at making irregular residence difficult and costly through labour market controls, for example, employer sanctions, employers’ deputation to check for identities, labour site inspections) (Brochmann & Hammar, 1999; Broeders, 2009; Broeders & Engbersen, 2007; Cornelius, 2005) and policies aimed at the exclusion of irregular migrants from public services (identification checks in order to use services) (Broeders, 2009; Van Der Leun, 2003; Van Meeteren, 2010). (b) Policies directed towards the identification, detention and expulsion of irregular migrants (identification and surveillance systems, random checks in public spaces, administrative detention, readmission agreements) (Broeders, 2009; Engbersen & Broeders, 2009; Schinkel, 2009; Schrover et al., 2008; Van Meeteren, 2010). (c) Policies directed at the regularization of irregular migrants (collective and individual regularization, de jure and de facto regularizations) (Baldwin-Edwards & Kraler, 2009; Boswell & D’Amato, 2012; Chauvin, Garcés-Mascareñas, & Kraler, 2013; Engbersen & Broeders, 2009; Finotelli, 2006; Papademetriou, 2005; Schrover et al., 2008).

In a different way, immigrant policies address the management of the immigrant populations, their integration, and the improvement of their living standards (Van Der Leun, 2003). Though usually not explicitly directed towards irregular migrants, these policies can have a tremendous impact on their lives. A first important policy within this group is the one that establishes the limits, rights, conditions and progression of migrants’ status towards obtaining citizenship (Chavez, 2007; Finotelli, La Barbera, & Echeverría, 2018; Garcés-Mascareñas, 2012; Isin, 2009; Joppke, 2010; Mezzadra, 2011; Ngai, 2014; Ong, 2005). While the classic distinction among citizens, denizens and aliens (Hammar, 1990) is fundamental, many scholars have shown that a greater variety of statuses and, hence, of hierarchies subsist within those categories (Broeders, 2009; Castles, 2004; Cvajner & Sciortino, 2010b; Finotelli & Sciortino, 2013; López Sala, 2005; Sciortino, 2013; Vasta, 2011). Probably the most relevant aspect of this policy concerns the establishment of the conditions for denizens to keep a regular status and the period of time before eventually becoming citizens. While an open, limitedly-conditioned policy may lead to an efficient progression along statuses, a closed, strongly-conditioned policy may imply drawbacks, slow advance and the possibility of cases of befallen irregularity. A policy within this cluster, that has a direct influence on irregular migrants, is the one that establishes the rights to which they are entitled. In this respect, a variety of arrangements can be discerned, ranging from the absolute exclusion and negation of rights in the Gulf Countries to the full entitlement to social services in countries, like Spain (Arango, 2005; Massey, 1999). For a schematic view of all the main policies affecting irregular migrants, see Table 2.1.

Table 2.1 Policies that directly affect irregular migration

4.3 Policy Implementation

The efforts to identify, classify and comparatively analyse migration policies in order to understand more fully irregular migration, have proved inadequate. Since the early 1990s, many scholars have highlighted the existence of a gap between the laws and policies stated on paper and what they effectively achieved in “reality” (Cornelius et al., 1994). This awareness stimulated an intense debate over the need for a more comprehensive understanding of policies and their interaction with social life. Within this debate, a group of scholars underlined the necessity to shift the focus from policy formation or policy classification to policy implementation (Castles, 2004; Guiraudon & Lahav, 2000; Van Der Leun, 2003). Whereas many studies existed on laws, explicit regulation, policy documents and decision-making processes, scarce attention had been given to their implementation as well as to the resilience of lower-level counterforces (Lahav & Guiraudon, 2006; Van Der Leun, 2003). As pointed by Van del Leun, a large body of literature not directly concerned with the study of migrations, had already “warned against straightforward ideas about the process of implementation of public policies” (Van Der Leun, 2003, p. 28).

The shift of attention to implementation dramatically increased the complexity of the picture. This has posed a number of methodological and epistemological problems. As long as the focus was on laws and regulations, researchers could refer to the official documents and statements by politicians and administrators. Enquiring into implementation, instead, forced them to get out of the libraries and adopt qualitative strategies to find and recompose the pieces of the puzzle. The information gathered in interviews with politicians, bureaucrats, migrants and many other social actors offered a prism of different perspectives that were rarely coincident. Moreover, because of the sensitive character of the information requested, the probability of getting embellished answers or no answers at all was high.

Notwithstanding these difficulties and the relatively recent attention given to implementation, the efforts made in the last two decades have produced significant results.

On the one hand, theoretical attempts have been made to develop frameworks of analysis. Since every national context produces distinctive practices of implementation, two questions have been raised: (a) what determines the specific mode of implementation? (b) How is it possible to explain differences? Four aspects have been suggested as crucial in order to understand different practices: the peculiar national regulatory styles and traditions; the organizational culture of bureaucracies and the degree of discretionality; the grade of isolation of bureaucracies from external pressures; the social attitude and toleration towards informality (Guiraudon & Lahav, 2000; Jordan et al., 2003; Lahav & Guiraudon, 2006; Van Der Leun, 2003). This approach also implied an extension of the actors to be taken in consideration: not only politicians and legislators, but also bureaucrats, policemen, civil servants, teachers, healthcare servants, etc. The focus had to be given to those “street level bureaucrats” that, at the end of the command chain, really enforce policies (Heyman & Smart, 1999; Scott, 1998).

On the other hand, researchers have analysed policy implementation in different countries with the purpose of detecting possible common trends. Lahav and Guiraudon have indicated an on-going shift of focus in the implementation of policies. While before the migration crisis of the 1990s, controls were limited to border enforcement and were implemented exclusively by states’ central institutions, after that, controls have been moving “away from the border and outside of the state” (Guiraudon & Lahav, 2000). This process has followed a threefold strategy: a shift outwards, with the adoption of remote control policies; a shift upwards, with the development of international frameworks for control; a shift downwards, with the delegation of control duties to the local institutional level. In 2008, Doomenrik and Jandl proposed another interpretation of this process. They suggested that states’ controls are expanding: forwards, externalizing implementation outside the borders; backwards, adopting internal controls and checks in public places and workplaces; and inwards, with an expansion of the requirements placed on migrants (Doomernik & Jandl, 2008).

Another group of scholars have observed a slow but constant shift in the logic of policy implementation (Broeders, 2009; Broeders & Engbersen, 2007; Engbersen, 2001). Broeders characterized this shift as the alternation between two contradictory logics of exclusion: exclusion from documentation/registration and exclusion through documentation/registration (Broeders, 2009). The first logic intended to exclude irregular migrants, denying them the possibility to acquire the documents necessary to access public services. While it may have been effective in fencing migrants’ access to welfare, this logic did not prevent the growth of irregular migration and was ineffective in expelling them. The main objective of the second logic was precisely to make expulsions effective. The correct identification of migrants was the main condition that origin states asked for, in order to accept their citizens back, once they were expelled. While this process has occurred principally in Northern European countries, the second logic has been central to the European Union common policy and seems to be gaining importance in the rest of receiving counties. More in general, many authors have underlined the growing importance for the implementation of migration policies of identification technologies and surveillance systems (Engbersen & Broeders, 2009; Leerkes, 2009).

Finally, a number of scholars have suggested the need to look beyond policies closely related to immigration control in order to fully grasp migration management (Finotelli, 2009; Garcés-Mascareñas, 2012). In a recent article, Czaika and de Haas have written:

Many policies affect migration such as labour market, macro-economic, welfare, trade and foreign policies. Because they affect fundamental economic migration drivers, their influence might actually be larger than specific migration policies, which perhaps have a greater effect on the specific patterns and selection of migrants rather than on overall magnitude and long-term trends, which seem to be more driven by structural political and economic factors in origin and destination countries (Czaika & De Haas, 2013, p. 5).

It seems possible to conclude that only the joint analysis of the interaction and the implementation of migration and refugee policies, labour market policies and welfare policies allows for a full picture of the framework within which irregular migration emerges and evolves.

5 Irregular Migrants Lived Experience

From a very different standpoint, a whole bunch of studies on irregular migration has devoted its attention to enquiring into migrants’ lived experiences. These studies, more from a sociological and anthropological perspective, have researched into a number of different issues, producing a vast and differentiated literature. The emphasis was on the agency of migrants, on their interaction with the structures of the receiving society and on the consequences of such interaction on their lives. The leading questions have been the following: (a) How do irregular migrants manage to live in a society that does not recognize them as legitimate members? (b) What strategies do they implement to be able to work? (c) How do public opinion and civil societies react in hosting countries?

For a more schematic analysis of this literature, it was chosen to consider three main broad thematic groups.

5.1 Life, Adaptation and Social Interactions

The shift of focus from policies to migrants’ experiences and social interactions raised important methodological questions and produced a number of different perspectives. Different analytical tools have been proposed to make sense of a complex and dynamic phenomenon in which both structures and individuals’ agency need to be considered. The concept of strategy is the one that has been prevalently used in the literature (Engbersen, 2001). Van Nieuwenhuyze has recently used the concept of trajectory. Her aim was “to gain an insight into the transitions and choices made by immigrants, and to explore their decisions and motivations within a specific economic and political opportunity structure”(Van Nieuwenhuyze, 2009, p. 19). Cvajner and Sciortino adopted the concept of career, intended as “a sequence of steps, marked by events defined as significant within the structure of actors’ narratives and publicly recognized as such by various audiences”(Cvajner & Sciortino, 2010a, p. 2).

The different emphasis given to either structures or agency has fostered an interesting and on-going discussion on the appropriate understanding of irregular migrants’ conditions. Should they be considered as victims that passively undergo the consequences of an unfair destiny or as active agents that consciously choose irregularity as a life strategy (Bloch & Chimienti, 2011)? Are they “modern-day slaves” or “villains” that break the law for their own interests (Anderson & Ruhs, 2010)?

The accounts that have adopted the first perspective have underscored the difficulties experienced by irregular migrants. On the one hand, many scholars have researched on their working and social conditions. A propensity towards precarious work, social immobility, poor housing and limited access to healthcare has been widely registered (Ambrosini, 2011, 2012, 2016, 2018; Bloch & McKay, 2017; Bloch, Sigona, & Zetter, 2009; Chavez, 1991; Goldring & Landolt, 2011; Mahler, 1995; Van Der Leun, 2003; Van Nieuwenhuyze, 2009). Studies on the US case have reached milder conclusions (Chavez, 1991, 1994; Massey & Espinosa, 1997). The extensive analysis of the Dutch case has led Engbersen and his colleagues to propose the marginalization thesis. The main idea is that the enforcement of internal control policies and the augmented pressure on irregular migrants have increasingly deteriorated their social conditions. The impossibility to access social services and get employed have pushed them “further underground”, forcing them to accept exploitative conditions or even to turn to crime (Engbersen, Van Der Leun, & Leerkes, 2004; Leerkes, Van Der Leun, & Engbersen, 2012).

On the other hand, the personal feelings, attitudes and identity negotiations that irregular migrants develop in relation to their status have been investigated (Coutin, 2005a; De Genova, 2002; Engbersen, 2001; Fernández-Esquer, Agoff, & Leal, 2017; Vasta, 2011; Willen, 2007). Engbersen has argued that the illegal status is a master status, “a dominant social characteristic overshadowing all other personal characteristics” (Engbersen, 2001, p. 240). In this sense, illegal status influences the establishment of all social relations and migrants need to learn to live as irregular migrants. De Genova underlined how the “palpable sense of deportability” and not deportation itself, has a concrete effect on the existence of migrants. “The spatialized condition of “illegality” reproduces the physical borders of nation-states in the everyday life of innumerable places throughout the interiors of the migrant-receiving states” (De Genova, 2002, p. 439). This way, “a spatialized and typically racialized social condition”, that becomes functional to the exploitation of migrants, is produced. Willen has studied how the condition of irregularity and the permanent possibility of being detected translate into observable behaviours and “somatic modes attention” on the part of irregular migrants. “Migrant illegality affect not only the external structure of migrants’ worlds, but can also extend their reach quite literally into illegal migrants’ “in-ward parts” by profoundly shaping their subjective experiences of time, space, embodiment, sociality, and self” (Willen, 2007, p. 10).

After a critical review of this literature, Van Meeteren has argued that the survival perspective has become a widespread convention. The main limit has been an excessive emphasis on structure over agency and, therefore, a limited ability to acknowledge phenomena like irregular migrants’ upward mobility; the inability to distinguish different irregular trajectories and outcomes; a tendency to underestimate the role of migrants’ strategies, aspirations and skills. Building on this critique and trying to understand more in depth the incorporation of irregular migrants, Van Meeteren developed a model of analysis based on irregular migrants’ aspirations. From this perspective, contexts do not mechanically constrain or construct irregular migrants’ actions. Instead, they create a certain window of opportunities and migrants, on the basis of their own personal characteristics, may take advantage and react to it. This implies that, within the same structural context, irregular migrants with different aspirations may attain different grades of incorporation (Van Meeteren, 2010, pp. 31–32).

Although the passive perspective has unquestionably been preponderant, a noteworthy group of scholars have been adopting a different perspective. The acknowledgment that very few irregular migrants live an underground life and that, on the contrary, they generally live in the midst of host societies, has forced some initial persuasions to be reconsidered (Düvell, 2011b). Analyses moved away from dichotomies, like included/excluded or victims/villains. The focus was placed on migrants’ individual characteristics and social skills, in the search for variables that could help or deter their incorporation. In this regard, many factors have been discussed, for instance: the role of networks and ethnic communities (Ambrosini, 2017; Cvajner & Sciortino, 2010b; Mahler, 1995; Triandafyllidou, 2017; Van Meeteren, 2010); the role of social, economic and cultural capital (Bourdieu, 1986); the role of time (Cvajner & Sciortino, 2010b); and the role of transnational networks (Portes, 2003; Van Meeteren, 2010). The multiplication of variables in the framework of analysis inevitably leads to a much more complex scenario regarding outcomes. Not only do different contexts set different windows of opportunities but, within each context, different migrants are more or less capable of seizing those opportunities.

On the basis of these developments, in the last few years, efforts have been made in the direction of a diversified understanding of irregular migration (Cvajner & Sciortino, 2010a; Van Meeteren, 2010; Van Nieuwenhuyze, 2009). In this respect, while the most promising tool to advance in this direction is the development of comparative analyses of irregular migrants, in different contexts the available studies are still limited (Van Meeteren, 2010).

5.2 Work and Subsistence

Probably the aspect that has received most attention regarding the lived experience of irregular migrants has been related to their economic integration. Also within this debate, a shift from a survival to a more nuanced perspective has been recorded. A number of issues have been researched. First of all, the employment sectors (Baldwin-Edwards & Kraler, 2009; Düvell, 2011b; Kraler & Rogoz, 2011; Vogel et al., 2011). Even if important geographical and contextual differences exist, irregular migrants are usually employed in similar sectors, in particular: agriculture, construction, textile industry, domestic- and care-work, service sector, and prostitution (Düvell, 2011b).

This particular pattern of employment has been widely analysed in connection with the process of restructuring in the economies of the receiving countries. The work of Piore has been path-breaking in signalling the emergence of dual-labour markets (Piore, 1980): on the one hand, highly-skilled, well-paid, secure jobs; on the other, increasingly precarious, insecure, low-skilled jobs. Whereas the segmentation of labour markets was initially considered a pattern affecting only post-industrial economies, the works of Sassen have convincingly shown that it is a feature affecting most of the global economy (Sassen, 1998). Many other scholars have advanced similar analyses and have proposed different concepts to describe this process: flexibilization, informalization, precarization, etc. (Castles, 2010; Goldring & Landolt, 2011; Kloosterman & Rath, 2002; Sassen, 1998; Schierup et al., 2006). A whole sub-category of studies has focused on the relation between the informal economy and irregular migration (Kraler & Rogoz, 2011; Papademetriou, O’Neil, & Jachimowicz, 2004; Reyneri, 2004; Samers, 2004; Sassen, 1998; Triandafyllidou, 2009).

Another group of scholars have studied the employment strategies of irregular migrants. Many tactics have been discovered: informal employment; self-employment; use of fraudulent papers; and renting of authentic papers (Coutin, 2003; Van Meeteren, 2010). As an answer to the increased controls on the labour market, the recurrence to middlemen and sub-contracting has been a widespread strategy (Broeders & Engbersen, 2007; Massey, 1999; Schierup et al., 2006; Sciortino, 2004a). Engbersen and his colleagues have argued that the fight against informal employment may push irregular migrants to constantly change their sector of employment or even to turn to minor criminal activities as the only option to get an income (Broeders & Engbersen, 2007; Engbersen, 2001; Engbersen & Broeders, 2009; Engbersen et al., 2004; Leerkes et al., 2012).

5.3 Irregular Migrants’ Counterstrategies

As just mentioned, an important strand of research on irregular migration has concentrated on the strategies that migrants develop in order to bypass state controls. From this perspective, migrants are all but passive victims of state action. Indeed, they observe, analyse, share information, develop counterstrategies, and adapt to new conditions (Cornelius & Salehyan, 2007; Schweitzer, 2017; Stavilă, 2015). As noted by Düvell, irregular migrants are often individualist and entrepreneurial, highly responsive to labour-market needs and more mobile than indigenous populations (Düvell, 2006, 2011b). To act like this, they can usually count on extensive networks of friends, relatives, co-nationals and co-ethnics.

Various concepts have been proposed to address this complex web of actions, tactics, informal networks, etc. Scott has proposed the concepts of “weapons of the weak” and “shadow institutions” to acknowledge those everyday forms of resistance that are put in place by the less favoured in contexts of social inequality (Scott, 1998, 2008). A similar idea lies behind Hughes’s concept of “bastard institutions” (Hughes, 1994 in Leerkes, 2009). Engbersen has suggested the notion of “residence strategies” to refer to those “strategies aimed at prolonging residence and avoid deportation” (Engbersen, 2001, p. 223). More recently, Bommes and his colleagues have used the concept of “foggy social structures” to highlight those “social structures that emerge from efforts by individuals and organizations to avoid the production of knowledge about their activities by making them either unobservable or indeterminable” (Bommes & Kolb, 2002, p. 5 in Engbersen & Broeders, 2009, p. 868; Bommes & Sciortino, 2011;).

As regards the specific tactics developed by irregular migrants, a diversified picture has been sketched. Engbersen has identified six tactics: mobilization of social capital, bogus marriages, manipulation of identity, operating strategically in the public space, legal action, and crime (Engbersen, 2001). Vasta has focused her attention on the functioning of the paper market. She has shown how irregular migrants engage in a dialectic process with the structures and control mechanisms of receiving societies. Buying, renting, and borrowing someone else’s papers are part of a productive process by which they permanently construct and re-construct their subjectivity (Vasta, 2011). Van der Leun, working on the Dutch case, has shown how irregular migrants are able to find and actively exploit the loopholes existing in the legislation and in the implementation of control policies (Van Der Leun, 2003). On the one hand, the complexity of legislation, the different dimension and sectors of application and the existence of various and often-uncoordinated levels of governance determine the presence of legal ambiguities, contradictions and voids. On the other, irregular migrants and their networks, often with the help of lawyers, NGO’s and even street-level bureaucrats, successfully learn to take advantage of them (Ambrosini, 2017).

6 The Consequences of Irregular Migration

To conclude, an important group of studies has enquired into the effects of irregular migration on receiving societies. These have been analysed from a number of perspectives and have usually given way to heated debates. In particular, three questions have been crucial: (a) What are the effects of irregular migration on the economies of the receiving countries? (b) What are political effects? (c) What are the social effects?

6.1 Economic Consequences

From an economic point of view, many questions have been raised, for instance, the effects of irregular migration on: production, consumption, fiscal outcome, wages distribution, segmentation of the markets, etc. (Düvell, 2006; Espenshade, 1995; Hanson, 2007; Koser, 2010; Portes, 1978). As pointed out by Hanson, in receiving societies, there is a widespread belief that irregular migration negatively affects the economy. Nevertheless, these ideas are rarely rooted in comprehensive economic analyses and derive more often from politicized opinions or simple prejudices. A more objective approach needs to acknowledge both the benefits (the increased availability of workers, the better use of resources, the boost on tax revenues) and costs (the use of public services and infrastructures, the lowering effect on some wages) of irregularity. Moreover, it needs to consider that these effects are not uniformly distributed and that, while some parts of society may benefit, some others may lose. On the whole, Hanson concludes that irregular migration has a limited impact. In the case where it persists, it is because a strong economic rationale subsists, at least on the part of the productive structure. In particular, for those businesses that are subject to market fluctuations, irregular migration represents a much more efficient and flexible solution than legal migration (Hanson, 2007).

Another well-established idea about irregular migration hypothesizes a substitution effect between irregular migrants and native workers. Research has shown little evidence of this. On the contrary, a complementarity role has appeared more plausible (Düvell, 2011a, 2011b; Jordan & Düvell, 2002; Reyneri, 1998, 2004; Samers, 2004; Van Meeteren, 2010). As pointed out by Düvell, irregular migration may even create “new markets for jobs and allow indigenous populations to enter the labour market” (Düvell, 2011a, p. 64; Young, 1999). In this respect, he presents an example of how the availability of irregular workers can generate a positive economic cycle. Their low wages make it affordable for lower-income households to hire migrants as domestic workers. This, on the one hand, creates a new employment market. On the other, it “frees indigenous women from housework and allows them to re-enter the labour market”. Households’ incomes increase, state revenues rise and a new market of lower-priced goods and services is generated for low-wage workers (Düvell, 2011a, p. 64).

Considerable attention has been focused on the impact of irregular migration on the welfare state (Baldwin-Edwards, 2004; Bommes & Geddes, 2000; Düvell, 2006, 2011a; Sciortino, 2004b) and, more in general, on the state budget. Bommes and Geddes have underlined that, since every national context is different, generalizations are problematic. Each state is based on a different historically-established concept of nation, a different mode of defining loyalty, a different immigration history, and a specific welfare regime. Each state, then, provides a distinct repertoire of public services by using different organizational infrastructures (Bommes & Geddes, 2000; Esping-Andersen, 1990). This implies that the impact of irregular migration will be necessarily differentiated and that each case needs to be analysed autonomously. On the whole, however, as highlighted by Düvell, “in many countries irregular immigrants have no, or only limited, access to public services and avoid any interaction with statutory agencies; therefore, often there is almost no negative welfare aspect” (Düvell, 2006, 2011a, p. 64).

A number of other possible negative effects of irregular migration have been alleged: unfair labour competition, decrease in wages, displacing of indigenous workers, undermining of power relations between organised workers and employers, tax evasion, illegitimate claim for, or use of, social services, congestion of the housing market, undermining of the rule of law, and exploitation and emergence of criminal milieus. Nevertheless, these phenomena tend to occur on a small scale because numbers are very limited (Düvell, 2011a; Koser, 2010).

6.2 Political Consequences and Social Consequences

Political and social consequences of irregular migration are another topic that has been extensively enquired. Also in this case, research has had to struggle against widespread preconceptions.

The idea of an on-going invasion, often fostered by the sensationalized use of images and titles in the media, raised doubts about the actual strength of states. In particular, irregular migration seemed to threaten their sovereignty and endanger their internal security (Broeders, 2009; Dal Lago, 2004; Koser, 2010). This second aspect gained relevance especially after the terrorist attacks in the early 2000s in the US and Europe (Huysmans, 2006). In a number of countries, right-wing parties emerged to mobilize and give voice to anti-immigrant opinions (Freeman, 1995). More in general, a phenomenon that had been until then essentially marginal, started to gain more and more attention and to become the object of public discourses (Kraler & Rogoz, 2011).

Notwithstanding the real extent to which irregular migration challenged receiving states (for a thorough discussion, see Chap. 3), the attention that the phenomenon reached in the public opinion and the fast politicization that followed, induced most governments to give top priority to the issue. The main result, as mentioned before, was a general trend towards restriction and a widespread implementation of policies and initiatives explicitly directed against irregular migrants. The change of paradigm was skilfully represented by the metaphors and slogans that were used: “zero migration policy”, “Fortress Europe”, “Panopticon Europe”, and “prevention through deterrence” (Broeders, 2009; Cornelius & Salehyan, 2007; Engbersen, 2001). These developments had a number of consequences. As regards migration, the financial and human costs of crossing the borders dramatically rose; previously circular or seasonal fluxes transformed into permanent settlement and the role of people smugglers and human traffickers increased (Broeders, 2009; Cornelius, 2005).

As shown in this chapter, irregular migration has received increasing attention in recent decades. This has resulted in a wide and diversified literature that has adopted a number of perspectives and has tried to provide answers to a number of questions. The attempt to briefly review this extensive literature was made not with the aim to exhaustively cover all that has been written. The aim, instead, was to offer an overview of the main issues that have arisen and the main approaches that have been adopted to provide possible answers. This overview has deliberately concentrated principally on the descriptive works or on the descriptive parts of the works that have been analysed. In the next chapter, the focus will shift to the theoretical explanations that have been put forward to explain irregular migration.