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Migrant economies: opportunity structures and potential in different city types

In this paper we wish to appraise how opportunities for migrant economies and their role in urban development may differ among various city types. The article contributes to the debate about the relationship of migrant economies and urban development and takes up two perspectives: it examines local opportunity structures for migrant entrepreneurs and sheds light on migrant economies’ potential for urban development. To address the many interrelated historical and contemporary processes in cities that influence migrant economies, we adopt the rescaling and the mixed embeddedness approaches. Studies on the role of migrant economies in urban development have predominantly focused on metropolises. Based on mixed-methods case studies in two medium-sized German cities, we ask how different city types influence the opportunities and potential of migrant economies for urban development. ARTICLE HISTORY Received 27 July 2017; Accepted 23 July 2018


Introduction
Increasingly, cities are recognizing migrant economies as an asset to urban development. These economies provide employment for migrants and nonmigrants in various business sectors, foster the revitalization of (deprived) neighborhoods and their social cohesion, enrich local supply structures, strengthen transnational trading networks, and contribute to the general social, economic and political inclusion of migrants (e.g. Hall 2011;Mestres 2010;Nuissl and Schmiz 2015). Recently, in metropolitan gateway cities, particular attention has been paid to agglomerations of migrant-owned shops, cafés, and restaurants which provide marketable places of leisure and consumption (Aytar and Rath 2012). The cosmopolitan flair of these ethnic neighbourhoods is used to attract tourists and new entrepreneurs in both the knowledge economy and the creative industry alike (Shaw 2011). These effects of migrant economies on urban development have predominantly been examined in metropolitan cities, leading to a gap in knowledge about the potential of migrant economies for urban development beyond these cities.
Research has only gradually begun examining the different local factors crucial to the opportunities of migrant entrepreneurs and those entrepreneurs' potential for urban development in various city types (Glick Schiller and Çağlar 2009;Hatziprokopiou, Frangopoulos, and Montagna 2016;Ram, Jones, and Villares-Varela 2017). We conjecture that there are differences between the development of migrant economies and their role in different city types, which are still under-researched in migration studies and urban studies.
In order to fill this research gap, the specific aim of this study is to analyse factors influencing both the role of migrant economies in the development of medium-sized cities and the opportunities for migrants as entrepreneurs, using Braunschweig (West Germany) and Rostock (East Germany/former GDR) as case studies. To address the many interrelated historical and contemporary processes in both cities, we adopt a scalar perspective that differentiates four relational city types on a scalar continuum, and combine it with a mixed embeddedness-perspective (Glick Schiller and Çağlar 2009;Kloosterman, van der Leun, and Rath 1999).
We define migrant economies as businesses of firstand second-generation immigrants, irrespective of their nationality (Rath and Swagerman 2016, 153), and analyse them from a perspective of local politics. We take this definition of migrant economies as our starting point for three reasons: First, our focus lies not on analysing single businesses and migrant entrepreneurial activities in their internal structure and strategies, but on understanding how the concept of "migrant economies" is applied externally and what different meanings it evokes. Second, as this definition aligns with German statistical data and political programmes (e.g. IQ 2017), it allows us to better connect to our research field, avoiding terminological confusion. Third, empirical evidence of an ethnic enclave economy defined as a spatially dense setting of entrepreneurs and their employees who serve mainly costumers from the same ethnic background with specific "ethnic" products has only been found in a few metropolitan gateway cities thus far. Therefore, we feel that applying such a definition would result in a restricted research focus which might overlook existing patterns of migrant entrepreneurship in the medium-sized cities under scrutiny.
Germany currently provides an interesting example for examining the role of migrant economies as an asset for urban development and local opportunity structures in medium-sized cities: on a national scale, the number of selfemployed migrants has almost tripled since the 1990s, leading to around 750,000 migrant entrepreneurs today (Leicht and Langhauser 2014, 6f.). This means the self-employment rate for the non-migrant and migrant working populations is now similar. With 2.2 million employees, migrant entrepreneurs provide 18 per cent of all jobs in owner-managed enterprises. Furthermore, a changing structure in the migrant entrepreneurs' line of businesses has been observed, diagnosing an increase in knowledge-based enterprises and, thus, a significant innovation in the migrant economy. Additionally, over half of the population with a migrant background does not live in big German metropolises, but rather in small-and medium-sized cities and in rural areas (BVBS 2012;Gans and Schlömer 2014). The reasons for this spatial distribution of migrants in Germany are varied, and the distribution itself differs among various nationalities. Nevertheless, in historical perspective, one major development still shapes migrants' spatial distribution today: a system of recruiting foreign workers from abroad ("Gastarbeiter") implemented in West Germany beginning in the 1950s. This system led to the development of specific migration hotspots near industrial centres in Western Germany, which were not necessarily close to big metropolises. Moreover, with regard to the specific group of asylum seekers and refugees, a national allocation system ("Königssteiner Schlüssel") distributes newly arrived asylum seekers among the federal states, wherein they are further diffused, including to rural areas and peripheral cities. This paper proceeds by introducing the mixed embeddedness and the rescaling approach as a conceptual framework for analysing the relationship between the migrant economy's role in urban development and local opportunity structures in different city types. In a short review of current literature, we introduce some metropolitan studies on migrant economies and delve into how these relate to the few studies on smaller cities we found. The subsequent section introduces our research design, followed by an analysis of our case studies. The discussion focuses on the potential of migrant economies for urban development and local opportunity structures in medium-sized cities. We conclude with a summary of the main findings and highlight questions for future research.

Theorizing the relation between migrant economies, urban development and local opportunity structures
The rise in cities' interest in migration is related to new challenges they face in regional, national, and global competition, in which migration is increasingly being recognized as a resource in urban repositioning processes and development (Biskup and Schalenberg 2008;Colomb 2012;Feagin and Smith 1987;Hospers 2008). Cities are increasingly attempting to capitalize on their migrant population, and migrant policy-making has been moved from integration to economic development sections within urban administrations (Pütz and Rodatz 2013). As a result, there is a need to better understand not only the relation between migration and urban development, but also what opportunity structures drive or hinder the development of migrant economies in different cities. Coupling the mixed embeddedness and the rescaling approaches can help shed light on these questions.

Migrant economies' mixed embeddedness
When it comes to explaining the rise of migrant economies, we find two types of classic models in existing research (Pütz 2003;Waldinger, Aldrich, and Ward 1990). On the one hand, there are theories that understand migrant entrepreneurship as the result of individual or group-specific resources, including the assumed common ethno-cultural background and co-ethnic social networks of migrants. On the other hand, some approaches stress the important influence structural arrangements and regulations, mainly at the national level, have on migrants' opportunities as entrepreneurs. The relevant mixed embeddedness approach connects both strands based on the interaction approach (Kloosterman 2010;Kloosterman and Rath 2001;Kloosterman, van der Leun, and Rath 1999). Thus, it conceptualizes immigrant self-employment as embedded between the opportunity structures and individual resources of migrants.
Opportunity structures are defined as consisting of technological developments, production factors, market conditions, demand, welfare systems and the legal frameworks. Furthermore, opportunity structures include housing market policy, which is crucial for real estate markets and the spatial distribution of migrant economies, as well as neighbourhoods with their specific population structure, resources and spatial market structures. Individual or collective resources, in contrast, comprise qualifications, social networks and economic capital. Notably, the mixed embeddedness approach conceptualizes self-employment in terms of migrant agency: migrants self-dependently position themselves as entrepreneurs in labour markets, instead of being pushed into self-employment by blocked mobility or missing qualifications.
While the mixed embeddedness approach provides a framework for the analysis of individual resources and structural conditions at national, regional/urban and neighbourhood levels alike, there is room to improve the systematic evaluation of the city level, including through an increased awareness of various city types. Furthermore, it rather does not help in examining migrant economies' role in urban development. That is why we use the rescaling approach to complement our survey of migrant opportunity structures based on the mixed embeddedness approach.

Rescaling migrant economies
The rescaling approach is based on the idea of analysing migration in the city beyond "methodological nationalism" (Wimmer and Glick Schiller 2003). In doing so, it draws on three concepts: the global city (Friedman 1986;Sassen 1991), scale (Brenner 2004;Swyngedouw 1992), and neoliberal urban development (Brenner and Theodore 2002;Harvey 1989). The rescaling approach opposes the assumption that migrant practices and institutions are only relevant for global cities. In moving toward a relational repositioning of cities in the global and national hierarchy, the rescaling approach counters the notion of scales as a nested set of territorial units and the practice of theorizing cities relative to their national hierarchy, without regard to their global ties or historical and structural similarities (Glick Schiller and Çağlar 2009. The rescaling approach conceptualizes cities as positioned on a relational continuum from top-and up-scale (metropolitan) to low-and down-scale (medium-sized) (Glick Schiller and Çağlar 2009). Top-scale and up-scale cities have already succeeded in attracting substantial numbers of migrants. In those cities, global networks of highly educated migrants are an important resource for employers in the new economy, while a broad range of industries rely on low-skilled migrants. Additionally, migrant associations and institutions are well developed and rooted in a long-standing local migration history and supported by public resources. They have become part of the cultural capital of the city, and as ethno-cultural diversity and multiculturalism attract cosmopolitan talent and tourists, they contribute to its positioning. While there are several pathways for integration and a great degree of symbolic capital in migrant economies in top-and up-scale cities, the number of opportunities declines on the continuum to low-and down-scale cities. Here, like in top-and up-scale cities, migrants contribute to repopulating and redeveloping urban neighbourhoods. However, migrants' transnational and local ethnic networks do not suffice to give the city a cosmopolitan image, and sectors that employ highly skilled migrants are weak. Additionally, a lack of public resources and migrant professionals hinder migrant agency (Glick Schiller and Çağlar 2009).
Although the rescaling approach considers migrant entrepreneurs' role within urban development and their local opportunity structures, it does not elaborate on this mutual relation in greater detail. Thus, we must refine it with respect to our research interests.

Migrant economies in different city types
Combing the mixed embeddedness and the rescaling approach, we propose that the following categories help us understand migrant economies' local opportunity structures and their potential for urban development in different city types: (1) History: This category describes "the specific history of a city that has shaped its institutional and political structure and narratives" (Glick Schiller 2012, 897). Each city has its own experience with immigration, which determines not only the presence of different migrant communities, but also how urban populations and institutions regard newcomers and migrant economies. This influences the opportunities of migrant entrepreneurs.
(2) Economy: This category examines "the production/destruction of capital in a particular city and its region" (Glick Schiller 2012, 897). The sectoral and spatial structures of the regional and local economies also determine opportunities for migrant entrepreneurs. Other important economic factors in migrant entrepreneurship include neoliberal restructuring policies in national and international competition, and local socio-cultural lifestyles, consumer markets and tastes (Rekers and van Kempen 2000). (3) Positioning: This category elaborates on "the power hierarchies (economic, political, and cultural) within which a particular city is situated and to which that city contributes, both within and beyond their national borders" (Glick Schiller 2012, 897). Cities' economic, political and cultural positioning in a regional, national, supra-national, or global context influences the possibilities of migrant economies. (4) Migrants' infrastructure: This category scrutinizes "the ways in which these variations make it possible for migrants to situationally function as scalemakers within urban repositioning processes" (Glick Schiller 2012, 897). It examines migrant agency, including (transnational) networks and selforganizations like migrant entrepreneurs' associations. Furthermore, it describes migrants' access to funding and specific support policies, as well as migrants' representation in local political committees, the public and media. (5) Perceptions: This category highlights "the many ways in which migrants may be embraced by municipal leaderships in their efforts to regenerate and reposition their cities" (Glick Schiller 2012, 897). Local stakeholders' narratives on the importance of migration and migrant economies as assets or problems for urban development are particularly important.
With these five categories, we analysed our two empirical case studies along our two research questions: first, regarding the role of migrant economies in urban development, and, second, in terms of opportunity structures for migrant entrepreneurs. In the following section, we examine present literature on these two questions.

Migrant economies in metropolitan cities
As cities interest in the potential of migrant economies has increased, so have scientific studies on these. One prominent example is the growing body of literature concerned with the value of migrant economies as an "emerging symbolic economy" (Zukin 1995) for urban development in top-and up-scale metropolises. This literature shows branding attempts promoting discrete inner-city migrant neighbourhoods as ethnically and culturally vibrant places for visitors (Aytar and Rath 2012;Hackworth and Rekers 2005;Shaw 2011). Critical studies address these branding processes as part of negotiations around ethnic representation and belonging in contested places and demonstrate how municipal top-down branding strategies often contradict the complex identity formations within neighbourhoods (Ip 2005;Pottie-Sherman and Hiebert 2015;Schmiz 2017;Sheth 2010). Furthermore, the disregard for social, labour market, education, and housing inequality in branding processes increases social polarization (Pütz and Rodatz 2013).
A different body of literature shows how migrant economies can contribute to urban development in two further ways: in serving as nodes of neighbourhood communication and by providing their neighbourhoods with retail and service shops and ethnic products (IOM 2015). In these roles, migrant entrepreneurs are particularly important to migrant populations within their neighbourhoods (Haid 2013;Kaplan 2015;Wood 1997;Zhuang 2008). Another facet of the part migrant economies play in urban development can be seen in their contribution to processes of gentrifications. Different studies have demonstrated, for example, the creative practices of falafel snack bar owners, and how their strategic reaction to changing customer tastes makes them symbolic markers for gentrification processes in Berlin (Stock 2013;Stock and Schmiz 2017). In a similar vein, Yildiz (2013) describes how the spatial density of migrant entrepreneurs contributed to the gentrification of a marginalized area in Cologne into a hipster neighbourhood.
In addition to this body of literature on the potential of migrant economies for urban development, several studies highlight local opportunity structures for migrant entrepreneurs. Examples of structures supportive to migrant economies include transnational entrepreneurial networks, as well as city and private sector sponsorship for festivals in migrant neighbourhoods (Bergmann 2011). Generally, municipal politics play a crucial role for migrant economies, as demonstrated by Amsterdam's Chinatown, which has either flourished or declined, depending on municipal politics (Rath et al. 2017). In a similar vein, Hall (2011) highlights the influence of national regulations and city planning on migrant retail on a depressed London high street.
Thus, the increased interest of cities in migrant economies may impact how migrant entrepreneurs can compete in the marketplace. On the one hand, a monitoring by city officials may impact business internal labour strategies, leading to a formalization of working conditions, for example when informal working conditions and exploitative structures, such as illicit employment, exploitation of family and other work force, are revealed. Because self-exploitation is one of the core strategies of migrant entrepreneurship, this may lead to a loss of competitiveness (Schmiz 2013;Waldinger, Aldrich, and Ward 1990).
On the other hand, the interest of city officials in migrant economies can change the structure of the marketplace itself. It may lead to an increased competition among migrant entrepreneurs for municipal funding and competition among ethnically branded neighbourhoods within the city. This in turn increases the pressure for distinction and innovation. According to these studies, the quality of such structures determines the opportunities for migrant entrepreneurs in top-and up-scale metropolises.
While there is comparatively little research on the role of migrant economies in low-and down-scale cities, the studies which do examine such cities indicate that, like metropolises, they profit from the same potential benefits of migrant economies described above, though to a different degree (Fischer-Krapohl 2011;Fürst and Balke 2013;Idik 2010;Nuissl and Schmiz 2013). 1 One prominent example is Carstensen-Egwuom's (2011) study of the low-scale German city Chemnitz, which illustrates how municipal exhibitions stage migrant entrepreneurs as diligent, economically successful and well-incorporated citizens who boost local urban development to promote the local recognition of migrant entrepreneurs. Similarly, Glick Schiller and Çağlar (2013) focus on the specific urban restructuring and rebranding projects and policies in Halle, Germany, where local leaders' narratives about migrants reflect the development agenda. According to our review of the literature, the factors influencing migrant entrepreneurs' opportunity structures have rarely been addressed in studies on such low-and down-scale cities (but, c.f. Ram et al. 2012). That is why we feel it necessary to examine whether the premises for metropolises truly do apply to the same degree in low-and down-scale cities.

Research design
The study at hand is based on a three-year research project dealing with migrant economies' potential for urban and regional development. Given the scarcity of knowledge about migrant economies and their role for urban development in low-and down-scale cities, an explorative mixedmethod approach was applied. The fieldwork took place between March 2014 and November 2015. Starting from the research gap shown above, we compare two medium-sized cities that differ regarding structural indicators and migrant entrepreneurs' opportunity structures. We chose Braunschweig and Rostock to consider the different migration histories of the FRG and former GDR, respectively.
The research started with a statistical analysis of migrant economies for the two case studies. The qualitative part comprised a comprehensive document analysis (of integration concepts, urban and economic development plans, NGO documents, etc.) and participant observations at various formal and informal events. Following the qualitative paradigm, further data was collected through semi-structured expert interviews (Przyborski and Wohlrab-Sahr 2014). A total of forty-three interviews (n = 43, Rostock/HSR = 22, Braunschweig/BS = 21) were selected through a combination of theoretical sampling and snowball sampling (Przyborski and Wohlrab-Sahr 2014, 182ff.). These interviews highlighted, on the one hand, the role of migrant entrepreneurship for urban development in Braunschweig and Rostock. On the other hand, they concentrated on the support structures for migrant entrepreneurs and relevant stakeholders. The sample included a variety of local and regional stakeholders, such as representatives of the local administration, migrant self-organizations, and chambers of commerce (COC). Further, two group discussions were conducted to reflect interview contents with local and regional representatives from economic development agencies and other relevant institutions (Lamnek 2010, 372ff.).
The interviews were recorded and transcribed and all collected data was systematically analysed with QDA software. Inductive and deductive coding was combined and the empirical data was subjected to a qualitative content analysis with hermeneutic supplements (Kelle and Kluge 2010;Mayring 2010). The coding process began with the categories discussed in section 2 of this paper. During the analysis, we distinguished between statements that reflect the opinions of local stakeholders and those that give "context information" on the cities. All quotes were translated into English for the purpose of this article.

Comparing migrant economies in low-scale cities
In the following we present our empirical finding on each case study according to the five categories at the nexus of migrant economies and urban development discussed above, before discussing their unique qualities as low-scale cities.

Braunschweig
History (Inter-)national migration processes have been an integral part of Braunschweig's urban development since World War II. So-called displaced persons from the former eastern territories of German and refugees from the GDR, late repatriates and, particularly since the 1980s, a rising number of asylum seekers have entered the city (Bonkowski 2003, 8;Marschalck 1997, 45). Guest workers were recruited from 1959 onwards, especially for automotive industries and mechanical engineering (Bommes 1997, 258;Weber 1993, 9), making Braunschweig a node in guest-worker migration to West Germany. Our analysis revealed that migrant self-employment originated with guest workers and late repatriates as a niche economy, which later spread to a variety of sectors, such as restaurants, grocery stores, travel agencies, and tailor shops. There were sixty-two migrant-owned businesses in 1967 (Weber 1993, 42;BS_13).

Economy and positioning
Today, Braunschweig is the second largest city in Lower Saxony, located close to the state's capital Hannover and to Wolfsburg, home to Volkswagen's global headquarters. This spatial proximity to the most important drivers of the regional economy influences Braunschweig's positioning and the labour market for migrants as sub-contractors and skilled employees, as our empirical data indicate. The city's overall economy is based on manufacturing, services, and trading, with 78 per cent of jobs in the tertiary sector in 2014 (Stadt Braunschweig 2016c). In contrast, the migrant economy is concentrated in trade and craft. At 6.8 per cent in 2014, the city's unemployment rate is in line with the federal average, meaning that migrant entrepreneurs also profit from a relatively strong job market and customer base (Stadt Braunschweig 2016a).
Braunschweig brands itself with various images, particularly as a researchintensive region with a high density of international scientists and a technical university. Since January 2016, a Welcome Centre matches skilled and highly skilled internationals with local companies, shifting the city's focus to the recruitment of highly-skilled migrants. It further brands itself as a leading business location (Stadt Braunschweig 2015), focusing on the economic and innovative potential of creative industries. In addition, our interview partners consider the support infrastructure for start-ups to be well developed.

Migrants' infrastructure
Today, 25.6 per cent of Braunschweig's 253,000 inhabitants (31 December 2015) have a migratory background, 2 with people of Polish, Turkish, Russian, Kazakh, and Italian ancestry constituting the largest groups (Stadt Braunschweig 2016b, 2f.). This includes 10.2 per cent of the population who are foreign nationals, largely Turkish, Polish, Syrian and Italian citizens. We can see from the data that today, the 1,945 businesses run by people with foreign nationalities make up 11.2 per cent of all businesses (30 June 2014; Stadt Braunschweig 2014; own calculation). 3 These migrant-led businesses are spatially dispersed. Since the 1960s, migrants have intensively developed their own infrastructure, founding several migrant self-organizations. As early as 1970, the municipality became engaged in migration policy-making (Weber 1993). Nowadays, the municipal "Committee on Integration" works on access to the local labour market for refugees and asylum seekers, among other issues. As an important part of the city's cultural capital, Braunschweig's House of Cultures provides space for intercultural events. However, there are hardly any specific support measures for migrant entrepreneurs and stakeholder networks are rather poorly developed (Räuchle 2016). The missing awareness of state, market, and civil society stakeholders for migrant entrepreneurs' interests diminishes the latter's economic opportunities.

Perceptions
We have learned that Braunschweig's local stakeholders view migrant economies as a positive urban resource, albeit with some restraint. Migrant entrepreneurs are addressed as economicrather than ethnicactors that contribute to the city's economic development by adding value and economic diversity, i.e. through jobs and apprenticeship training positions. Nevertheless, the majority of interviewees value migrant economies for providing their neighbourhoods with (specialized) small retail and service shops. The following quote from a representative of a regional business development agency illustrates this sentiment: Here, we have many people with a migratory background, who have started selfemployment in the service industry or with shops from the traditional fruit shop to the traditional gastronomy or internet cafés. In these low-threshold business sectors, there is a large share of migrant entrepreneurs. (BS_6) Local leaders occasionally refer to migrant entrepreneurs' contribution to Braunschweig's urban flair and diversity, thereby also illustrating changing socio-cultural lifestyles, where dining out in migrant-operated restaurants has become an important attraction (Ram et al. 2002).
If you hear stories of Italians who have had so many ice cream parlours here, they basically have enlivened public places with their gastronomy. Our cityscape would have developed differently without them. Sitting outside, coming in contact with people, even the gastronomic culture has profited and became more cosmopolitan. (BS_4) Beyond these rather positive narratives, some interviewees from economic development agencies question the economic value and innovative potential of migrant entrepreneurship, reducing it to a by-product of blocked upward mobility due to a lack of education and language skills. Furthermore, employers like VW provide a high number of attractive jobs and thus make entrepreneurship a less attractive pathway for migrant labour market integration.

History
The low number of migrants in the former GDR population (1-2 per cent) consisted of foreign students and contract workers (Hess 2008, 74;Weiss 2013, 383f.). The latter, mainly from Vietnam, were employed in the city's key industries: seaport, textile, and construction (Müller 1996, 28f.). Our documents show that after 1990, when the former GDR economy was restructured into a free market economy, and a democratic political system was introduced, the structure of migrants in the Hanseatic city gradually changed, while remaining relatively low in numbers. New in-migration was mainly through the arrival and allocation of asylum seekers (Weiss 2013, 384). The xenophobic racist attacks in Rostock-Lichtenhagen in 1992 represented a major rupture in local integration history (Prenzel 2012, 9ff.), accelerating the development of the city's local integration policies and migrant support infrastructure (Hess 2008;HRS_7).
In the course of German reunification, when contract workers lost their jobs at state-owned companies and had little access to the poorly developed local labour market, self-employment became a central source of income. Particularly for the former Vietnamese contract workers, economic independence was linked to their right to stay. Experts in Rostock confirm: The alternative for many Vietnamese was peddling trade. They tried to survive on markets with a simple market stall. Those who were a bit cleverer bought a food truck and started an Asian snack bar. But not in a house, rather on markets and at different points in the city. (HRS_7) 4

Economy and positioning
In line with its urban development strategy "Rostock 2025", the city adopted the integration concept "Future in Diversity" in 2014 to brand Rostock as cosmopolitan, tolerant, and child-and family-friendly (Hansestadt Rostock 2014, 6;. However, migrant economies are not explicitly addressed in these repositioning attempts, as our document analysis revealed. Rostock is the largest city of the federal state Mecklenburg-Vorpommern and positions itself as the economic, scientific, and cultural centre of the region, making it a superior destination for migrants. Life sciences, logistics, aerospace, and wind energy complement the local harbour industry, all benefitting from the city's geographical location as a node in the Baltic and Scandinavian region (Hansestadt Rostock 2016). Most of Rostock's jobs are in the tertiary sector (around 84 per cent in 2014; Hansestadt Rostock 2015, 103). In 2014, its unemployment rate of 10.9 per cent was clearly above the national average of 6.7 per cent (Hansestadt Rostock 2015, 135), resulting in a weak job market for migrants and a need for alternative professional pathways. According to our interviewees, the support infrastructure for start-ups is well developed, and creative industries are increasingly considered an integral part of urban development. Despite the focus on highly-skilled internationals in knowledge-intensive sectors, the municipality and regional firms primarily recruit a domestic workforce (GD_HRS).
Migrants' infrastructure Nowadays, 6.7 per cent of Rostock's 206,000 inhabitants have a migratory background (Hansestadt Rostock 2014, 7) and 3.9 per cent are foreign nationals, with a majority within both categories coming from the Russian Federation, Ukraine, and Vietnam. The 808 spatially dispersed businesses run by people with foreign nationality make up 5.6 per cent of all businesses (30 June 2014; Hansestadt Rostock, Abteilung Gewerbeangelegenheiten 2014; own calculation). As a result of Rostock's history, local stakeholders from state, market, and civil society occasionally collaborate in developing specific support programmes for migrant entrepreneurs (HRS_23; Räuchle 2016). Nevertheless, these structures were initiated in the aftermath of German reunification, and immigrant entrepreneurship has since lost importance in local labour market politics. Apart from that, there is a huge variety of migrant self-organization in the city, and according to its self-presentation, the local "Board of migrants" represents the interests of all migrants.

Perceptions
Rostock's local stakeholders are sceptical about the relevance of migrant economies for the city's repositioning and development attempts, since the share of migrant economies is perceived as irrelevant in size and numbers, as well as less innovative. This is judged ambiguously, as the following quote of a COC's representative reflects: Only a small share of migrant entrepreneurs works in really innovative sectors [but it] is really honourable if entrepreneurs create jobs for themselves. So, for me, a 'successful' company does not only start with at least fifteen employees.
Additionally, migrant entrepreneurs occasionally form part of narratives that describe Rostock as a cosmopolitan, welcoming, migrant-friendly city that has overcome racist and xenophobic sentiments. Here, they are addressed as ethnic representatives of foreign cultures. In a similar vein, a few local stakeholders support the idea of integrating migrant economies in Rostock's branding strategies, even if this idea is not pursued in practice.

Braunschweig and Rostock as low-scale cities
Drawing on the scalar continuum proposed by Glick Schiller and Çağlar (2009), both cities rank as relatively low-scale, which affects migrants' opportunities as entrepreneurs and their role in the cities' development. As shown above, long established migrant communities provide the greatest number of migrant entrepreneurs. Both cities have, in contrast to their regional context, a relatively favourable integration infrastructure with positive influences on migrant entrepreneurs' opportunity structures. Additionally, stakeholders emphasize the role of migrant economies in the revitalization of neighbourhoods, and thus agree on their potential at the sub-local scaleone of the key characteristics of lowscale cities (Glick Schiller and Çağlar 2009, 192f.).
However, the well-developed start-up support infrastructure does not specifically focus on migrant economies. Though both cities promote themselves as cosmopolitan, migrant economies are not a strategic part of this image, especially in Rostock. Mirroring Glick Schiller and Çağlar's (2013) findings for Halle, both cities address migrant entrepreneurs primarily as economic actors and only secondarily as ethnic. Commonalities between the two case studies further show that local leaders' endeavours to reposition their cities value employed over self-employed migrants. Additionally, since 2014, local migration discourses in both cities have been dominated by debates around refugees and asylum seekers. The high numbers of newly arrived asylum seekers has strengthened the perceived dichotomy between "desirable" (highly skilled, families) and "undesirable" (asylum seekers) forms of migration, and thus has shifted urban discourse from asset-driven to problem-centred.
Braunschweig, however, cannot be characterized as low scale in all aspects: it forms part of an affluent economic region and is connected to globally competitive industrial and research networks. Furthermore, its long history of migration leads to well-established migrant communities who succeeded in developing their own infrastructures.

Discussing migrant economies beyond metropolitan gateway cities
Based on the previous theoretical thoughts and our own empirical insights, we wish to discuss the following two issues for metropolitan cities and our two case studies Braunschweig and Rostock: (1) migrants' opportunities as entrepreneurs and (2) their potential for urban development. Additionally, we draw conclusions on how our empirical results can enrich theory (3).
(1) Migrants' opportunities as entrepreneurs Established metropolitan cities draw on a long history of migrant economies, leading to a super-diverse landscape of businesses which potentially encounter a more open and tolerant climate among local stakeholders and the population as customers (Ram et al. 2002). Somebut not alltop-and up-scale cities have succeeded in developing a supportive environment of established migrant networks and organizations that offer specific support measures for migrant entrepreneurs (Rath and Swagerman 2016). Further, urban wealth and diversity lead to a diversified demand for products and services. Large firms subcontract services and depend on supply industries, creating opportunities for migrant businesses. A strong economic, cultural, and political positioning of a city fosters transnational business activities, allows for new service industries and increases funding sources for business openings from abroad.
In contrast, competition for business ideas and for the recruitment of employees in metropolises is higher (Rekers and van Kempen 2000). Moreover, the commodification of migrant economies raises questions regarding the negative impact of resource-driven policies, which support urban development processes that result in rising rents and, subsequently, displacement.
For Braunschweig and Rostock, our data shows that options for the implementation of new businesses are rather restricted by the lower presence of new creative and knowledge-intense industries, which traditionally draw a workforce of cosmopolitan consumers. Moreover, where diversity is less ingrained in the social fabric, the acceptance and consumption of ethnic goods and services is less likely. Furthermore, a lack of representation of migrant entrepreneurs in local politics and a lack of symbolic representation in urban space in both cities negatively impacts inclusion in local development programmes and support structures. Thus, it seems metropolitan cities provide better opportunity structures for migrant entrepreneurs.
(2) Migrants' potential for urban development As research on top-and up-scale cities has shown, such cities profit from migrant economies in many different ways. Migrant economies can offer significant symbolic value, for instance, which can help cities attract creative and knowledge-based industries as well as cosmopolitan workers and tourists. As such, agglomerations of migrant economies can play a major role in urban branding.
The conceptual distinction between immigrant enclaves and middleman minorities helps to differentiate possible contributions of migrant economies to urban development (Blalock 1967;Bonacich 1973;Portes and Manning 1986). Middleman minorities, defined as spatially dispersed migrant economies that serve a non-ethnic clientele, might contribute to neighbourhood development by securing local supply and preventing vacancies. However, in a dispersed form, their capability to generate a symbolic value for urban neighbourhoods is limited. The relational comparative perspective reveals that migrant economies mainly function as middleman minorities in our low-scale cities Braunschweig and Rostock, while they do both in top-and up-scale cities.
Furthermore, it can be assumed that the socio-political potential of migrant economiesmeaning the signaling effect of successful entrepreneursmay be higher in our case studies Braunschweig und Rostock. Studies suggest that marketing campaigns for the public image of migrant entrepreneurs have a higher visibility in low-and down-scale cities; i.e. successful migrant entrepreneurs are publicly presented (Carstensen-Egwuom 2011; Glick Schiller and Çağlar 2013). Our data confirms this.
(3) Theorizing back As we have shown, the rescaling approach allows for a qualitatively comparative perspective on migrants' opportunities as entrepreneurs and their potential for urban development in various cities. In doing so, this approach offers a relational typology of cities.
However, based on a systematic literature review and our empirical research, we suggest extending the concept for comparative migrant entrepreneurship research. Even though our case studies can be characterized as low-scale cities, few criteria spread across the whole scalar continuum and cannot clearly be assigned to one city scale. This raises questions about the meaningfulness of generalizing city models and, with that, assumed causalities (Ward 2010). In addition, the rescaling approach is based on the notion of neoliberal, linearly-progressing globalization and, with that, reproduces to a certain extent a teleological idea of city development. Given the broad scope of the comparative categories, further operationalization is needed, depending on the specific research question. In our case, this concerns a systematic clarification of relevant factors for the local opportunities of migrant economies and their potential for urban development. For the conceptualization of their impact on urban development, we suggest including theoretical insights from migrant economy research in the rescaling approach (see above). Additionally, insights from gentrification research help to theorize possible outcomes of urban development in diverse neighbourhoods and thus include migrant entrepreneurs' role as scalemakers (Parzer and Huber 2015;Stock and Schmiz 2017).
For the analysis of entrepreneurial opportunities, we support the call to more strongly contextualize entrepreneurship research within the mixed embeddedness approach (Kloosterman 2010;Welter 2011). While research already considers "context" on a national and global scale, the contextualizing of the local scale can still be improved. This can be achieved, for instance, by including local stakeholder networks to a greater extent, considering migrant economies in different policy fields (integration, economy and urban development), and integrating local consumer tastes into the analysis of migrant entrepreneurs' local opportunity structures, as others have noted (Ram, Jones, and Villares-Varela 2017;Rekers and van Kempen 2000).

Conclusion
The paper at hand argues for a context-sensitive analysis of migrant economies in different cities. It applies a rescaling and mixed embeddedness perspective to the medium-sized cities Braunschweig and Rostock to assess to what extent these results differ from the trends in such studies on metropolises.
The analysis has identified three findings: first, the roles and opportunities for migrant entrepreneurs in urban development processes differ between various city types, despite some similarities. Our research shows limited potential for migrant economies as a driver of urban development for lowscale cities. It further demonstrates that the relatively low positioning of a city diminishes migrants' opportunities as entrepreneurs. Second, the study shows different shortcomings of both the rescaling and the mixed embeddedness approach and highlights the need to refine the approaches to the specific area of research. Third, we demonstrate that even though municipalities worldwide find themselves under increasing pressure to seek competitive advantages, they do not all view migrant economies as an urban resource.
In future research, it will not only be necessary to compare the differing potential of migrant economies to influence urban development processes in various city types. Instead, international comparative analyses of migrant economies in a variety of low-scale cities are also needed to gain a better understanding of constricting local, regional, and global conditions, the contrasting roles of migrant entrepreneurship, and the role of cities in global repositioning aspirations. Such research would especially help to overcome the risk of staying within methodological nationalism in urban comparisons within a nation state. Notes 1. Recently, this has to be mentioned, a few studies have also tackled issues of migrant economies in rural areas of Europe (Munkejord 2017;Webster 2017). 2. "Migratory" or "migrant background" is an official statistical category from the German Federal Statistical Office and describes foreigners, migrants who have received German citizenship, people born in Germany with a foreign nationality, and persons born in Germany as Germans but with at least one migrant parent. 3. In Germany, local statistics on entrepreneurship only consider an entrepreneurs' nationality and fail to allow for their migratory background, unless they have a foreign citizenship (Hillmann and Sommer 2011). As a result, listed figures for Braunschweig and Rostock do not encompass all migrant entrepreneurs; the actual numbers are even higher. 4. Self-employment of mainly Vietnamese in Rostock in the 1990s has to be understood as a bottom-up process. Local policy makers implemented specific support politics mainly as a reaction to the rising numbers of migrant entrepreneurs.