Understanding international students beyond studentification: A new class of transnational urban consumers. The example of Erasmus students in Lisbon (Portugal)

For the last 10 years the city of Lisbon has been receiving an increasing number of international students, expanding considerably the supply of student accommodation. In spite of the resulting rise of a new and underdeveloped housing market directed to students, studentification is not exhibiting the usual concentration and segregation patterns of clustering across the city. On the contrary, the effects of student-related economic activities are spreading throughout Lisbon, overlapping with several urban transformations. An examination of international students’ lifestyles in Lisbon seems to demonstrate that diverse youth cultures of Erasmus students are colonising different districts and activities through diverse processes of belonging and distinction. Beyond the studentification literature (and its housing-supply centred perspective) it is necessary to recognise that international students become involved in broader urban processes such as the tourism industry, marginal gentrification or entrepreneurial creativity, thus becoming a new class of transnational urban consumers.


Introduction
Over the last decade, the new (neoliberal) global industry of higher education has been experiencing a time of expansion (Verger et al., 2016), especially the dynamic sector of internationalisation, that will grow from the 5 million that studied outside their home countries in 2015 to the expected 7 million mobile students by 2022 (OECD, 2015). International students are also a growing presence in European cities, mainly through the Erasmus programme, which is the most renowned and successful programme ever launched by the European Commission. Higher education students from 34 European countries make annually around 270,000 exchange stays (from 5 to 10 months) in different universities through a programme of credit equivalences and grants funded by the European Commission (European Commission, 2014). The absolute success and cultural importance of the Erasmus programme led to the production of several studies to evaluate the outcomes of the Union's 'flagship programme', often from an institutional perspective: the politics of internationalisation of higher education in Europe (Kehm and Teichler, 2007), the employment rates of former Erasmus students (Teichler and Janson, 2007), the learning process and the acquisition of competences while abroad (Maiworm, 2001), or the emergence of feelings of European identity among students after the stay (Sigalas, 2010;Van Mol, 2013).
More interesting is the student migration literature that addresses several other social processes related with the experiences of international students: the impact of staying abroad on social identity (Valentin, 2015), the friendship patterns of students when abroad (Hendrickson et al., 2011), the causes of student migration -the 'Pull & Push factors' (Liping et al., 2015) -or the multiple contact points between studying and working abroad in students' transnational biographies (Robertson, 2014). However, the importance of their everyday activities in a foreign country, the non-formal educational contexts they frequent and their consumption patterns when living abroad were generally ignored: searching for a home, frequenting particular bars, participating in social movements, getting attached to the new place. In this sense, the role of international students (or the more particular case of Erasmus students) as a new class of transnational urban consumers has been widely disregarded, and only the socalled studentification literature has assessed the impact of student populations on their urban contexts of arrival. In the case of the UK's studentification, particular neighbourhoods were affected by severe transformations related to the formation of 'student ghettos' that were increasingly segregated and concentrated in some urban areas (Duke-Williams, 2009).
However, Chatterton observes that studentification is not primarily a housing issue but a general commodification process of student life engaged with gentrification and urban regeneration (2010: 513). Following this statement, we propose to see Higher Education Students (hereafter, HES) as a transnational, distinctive social class of consumers and producers of urban culture (Florida, 2003) in the context of the neoliberal 'entrepreneurial turn' (Harvey, 1989). Among HES, international students seem to be particularly relevant in urban change because they participate in knowledge economy (as students), in travel economy (as strangers), and in leisure economy (as youth) from a socio-economic position that is above the average in their home countries. As a consequence, their distinctive lifestyles often (re)produce new, transnational, middle-class urban identities, mobilising several economic sectors directed to foreigners that are different from those directed to locals, such as in several apartments, nightlife spots, retails shops and tourist sites, as we will see later. In this sense, it is undeniable that international students benefit from (and take part in) the processes of gentrification in inner cities. They are beneficiaries of the planetary class-displacement, which is one of the major consequences of the global strategy of the financial forces that produce the 'rent-gap' also at a planetary scale (Slater, 2017). However, the current excessive dependence of gentrification/studentification literature on production and supply theories to explain the complexity of urban lifestyles could represent a backward step both in the acknowledgement of students' agency and in the recognition of their migrant trajectories as relatively autonomous processes .
After presenting the expanding sector of international students in Lisbon, we pose in this article some direct questions for the 'canonic' studentification literature: is this theoretical framework broad enough to analyse the complex contact points between student mobility experiences and urban change in geographies other than the UK? What is the meaning of students' patterns of clustering across the urban space when the 'segregation' and 'concentration' effect is missing in Lisbon's studentification? Beyond the housing-centered perspective, and taking international students as a new transnational urban middle-class, we will examine how they nurture the characteristics of knowledge-based, cognitive-cultural urban capitalism (Scott, 2014). In this sense, we explain the role of international students in favouring the expansion of the travelling economy (along with tourists and migrants), in 'discovering' new exploitable urban spaces (through marginal gentrification), and in producing urban value in cultural and creative industries. Finally we discuss the interdigitation of demand and supply theories in the field of gentrification in the light of international students.

Methodology
Although works on students and urban change often declare their debt to the seminal study of Chatterton on Bristol student geographies (1999), none have applied its ethnographic approach to the spatialisation of students' lifestyles within the consumption-oriented city. The following outline of the residential patterns and the lives of exchange students in Lisbon derives from evidence drawn from two years of fieldwork in Lisbon (2013Lisbon ( -2014. This comprised 32 in-depth interviews with international students (25), university staff (3) and members of organisations devoted to international students (4). Among the 25 students, 12 of them coming from different national origins and youth cultures were selected to participate in three focus groups on student lifestyles, and were met in their homes. In addition, countless informal conversations were recorded in participant observation sessions within student contexts such as pub-crawls, city walks, student parties, guided tours and a range of other events shared with foreign students in Lisbon. This last set of ethnographic encounters was based in Holton and Riley's (2014) innovative methodology 'the place-based walking interview', which capture the identities and senses experienced by the students within the urban space. Owing to the lack of information on student housing, these interviews, conversations and focus groups with the students were the unique available data to understand the patterns of occupation through the city. All these data were stored, classified and analysed using CAQDAS software, changing the participants' original names in order to protect their identities.

Erasmus students in Lisbon
As in other European cities, Erasmus students (among other international students) are a growing and noticeable presence in Lisbon, the capital and largest city of the Portuguese Republic which is located in the western part of the Iberian Peninsula where the River Tagus flows into the Atlantic Ocean. The city has a population of half a million (with 3 million in its metropolitan area) and is an Atlantic hub for commerce and finance, employment and leisure, communications and flows of capital and people, connecting with North America, Brazil, the PALOP 1 and the rest of Europe. Its Mediterranean climate, cheap prices and the cultural legacies of the Romans, the Moors and the rich architectural reminders of the Colonial Period make Lisbon an important destination for tourists worldwide. In this respect, several dynamics of urban transformation related to the growing presence of tourism and the politics of urban neoliberalisation have been observed in recent years (Rodrigues, 2010;Tulumello, 2016) while urban inequalities continue to grow (Carmo et al., 2015). However, Lisbon's municipality has been developing a strategic cluster of knowledge, innovation and creativity which has attracted several companies and entrepreneurs. According to the last known data, the academic year 2015-2016, 148,000 HES enrolled in the 95 higher education institutions (hereafter, HEI) sited in the metropolitan area of Lisbon, most of them inside the city: 71 centres with 125,000 students are located within the municipality limits (84.4 km 2 ). 2 Around 14,000 of this annual population of tertiary students (11%) hold a citizenship other than Portuguese, the majority (about 10,000) of whom live permanently in Lisbon for the entirety of their studies. Most of the students in this group come from countries historically and linguistically linked with Portugal and its former colonies: middle-class and wealthy people from Brazil and the PALOP (specially Angola and Cape Verde) who seek to graduate (Bachelors, Masters or PhD) in the European education system. 3 Other foreign students come to Lisbon for a shorter period of time (one or two semesters) on a range of exchange programmes, the vast majority of them being Erasmus students (around 4000), a relevant population of transnational mobile young people which is the focus of this article. 4 The growing attraction of Lisbon for foreign students has demonstrated a new trend over recent years when the enrolment of European students (mainly through the Erasmus programme) more than doubled its representation in the capital city of Portugal. Between 2008 and 2012, the percentage of Europeans (mostly Spaniards, Italians and Germans) grew from 15% to 35% of the total foreigners, surpassing Brazilians (despite their numbers growing slightly from 20% to 23%) and almost equalling the nationals from PALOP who have declined from 62% to 37%. This is the most important change in international student demographics in Portugal since the country became a net importer of Erasmus students (receiving more than sending), beginning a spectacular growth with Lisbon playing a leading role. In absolute numbers, Portugal was the ninth most popular destination among Erasmus students during the academic year 2012-2013, but the country has ranked second out of 15 in its growth rate (59%) for the last 5 years (6232 to 9894), only surpassed by Poland, a country 3.7 times more populous and 3.4 times bigger than Portugal and, therefore, with an expansion potential equal to the capacity of their cities and territory. As a result of this growth, the ratio of Erasmus students to the general student population in the country is astonishing: 34% of the foreign students in Portugal are Erasmus (fourth position out of 20) and 2.53% of all tertiary students in Portugal are Erasmus (second position out of 20, only surpassed by Ireland). Thus, returning to Lisbon (which receives a steady proportion of 40% of total Erasmus students in the country) around 30,000 Erasmus students have circulated through Lisbon between 2000 and 2013 (62% of them during the last 5 years). These are huge numbers for a city of its size and population: the transnational circulation of young exchange students within the limited urban territory of Lisbon should be of increasing significance in explaining some urban processes such as the shift to a leisure-centred urban economy and the transformation of the rented housing market.
But who are these students arriving in a new urban territory and how they differentiate from the regular local HES? International students could be considered broadly a 'migratory elite' (Musgrove, 1963) because they come from educational and socioeconomic backgrounds that are slightly above the average of HES in general (Windle and Nogueira, 2015). The same could be said about the family origins of the subpopulation selected in this article: Erasmus students (Souto-Otero, 2008). As a group of wealthier international students (when compared with their local peers) the Erasmus illustrate the capacity of this transnational urban population to induce processes of urban change through their middle-class practices of consumption. First of all, they are the broader, recognisable student-lifestyle community in European cities, very well known for their daily alcoholfuelled, sexually uninhibited events and parties, and for their strong desire to socialise with the entire community of young foreigners during the stay abroad. They are also very young (the average age is 22.5 years) and usually receive financial help from their parents (the grant provided by the European Commission is very low). This makes them consumers more than producers (in contrast, a considerable number of Brazilian students in Lisbon have part-time work) and specifically consumers of young, European middleclass to upper-middle-class lifestyles. Summarising, the massive arrival of Erasmus students in Lisbon could be seen as the temporary (but repeated cyclically, every semester) colonisation of a particular territory by a new class of transnational urban consumers.

Lisbon's studentification process
Studentification literature is devoted to understanding the effects of student populations in processes of urban change that affect particular districts around colleges. However, despite the growing numbers, the processes occurring in Lisbon are not characteristic of the classic boundaries expressed in the studentification literature: that is, differentiated housing geographies between segregated populations of either students and non-students or international and local students. The first scientific outline of studentification 'under the wider rubric of gentrification' (Smith, 2005: 75) was focused on the particular phenomenon of urban change caused by the formation of 'student ghettos' in English college towns. As a consequence of the massive growth in the number of HES, distinctive UK districts, centred around universities, started to receive a huge seasonal migrant youth population (from the UK and worldwide). Some actors (house owners and small-scale capital investors) supplied student accommodation, converting the existing single-family housing stock into houses of multiple occupation (hereafter, HMO). On the other hand, wellfinanced economic actors prompted the construction of new-build developments (cultural and retail services for students, university-maintained accommodation) as part of a wider strategy of gentrification in these areas (Hubbard, 2009). These middleclass residential districts were progressively occupied by significant concentrations of young people in shared student houses and residences which brought particular lifestyles and patterns of socialisation and consumption to the neighbourhood, causing the transformation of retail outlets, services and entertainment venues in the area. In any case, the studentification literature has dealt with variances of segregation, concentration and the density of student populations in particular urban areas (Smith and Hubbard, 2014), criticising the lack of interaction between different urban populations (Munro and Livingston, 2012;Smith, 2008Smith, , 2009).
However, in Lisbon it is not possible to point to specific studentified areas because student accommodation (for both locals and foreigners) is more or less spread over the entire city, also covering the most central neighbourhoods in spite of being far from the university or college faculties or being poorly connected by public transport. This also appears to contradict the studentification literature which stresses proximity to the campuses as the main driving force in choice processes and clustering (Sage et al., 2012: 599). Nevertheless, the medium size of Lisbon, its transport system and the structure of urbanism make the distances from home to the faculty irrelevant when compared with UK studentified clusters. AndreḾ artins, CEO of Erasmus Life Lisbon (ELL), an association that organises parties and tours for international students and also assists them to find accommodation through their huge rooms database, emphasises the impossibility of pointing out the main student housing areas in a map: '90% of international students are spread in an area that goes from Campolide to Saldanha and from Santos to Santa Apolo´nia, which means most of the city centre'. Rita Ferraz, CEO of Erasmus Lisboa (EL), an organisation for foreign students which provides an online booking service for finding accommodation, points to the stabilisation of Avenida Almirante Reis as the cause of this spread of student housing throughout the entire city centre: 'The area of Martim Moniz, Intendente and Anjos used to be dangerous, but in the last five years it has changed a lot and today there are student flats everywhere'. As a consequence, local and international students are dispersed throughout Lisbon in an extensive housing area sited between two opposite extremes of the municipality: the leisure nightspots of Santos, Cais do Sodre´and Bairro Alto, and the faculty areas around Avenidas Novas and Campo Grande. Although these specific districts are occupied by students in some density, it is not possible to consider them studentified as described in the literature: that is, forming segregation patterns or rapidly changing the social composition of the neighbourhood. The only segregation pattern we could find in Lisbon is a minority of Portuguese-speaking students (including the international ones coming from Brazil and PALOPs and the 38% of Portuguese students who moved to Lisbon from other districts) that tend to live separately from 'Erasmus environments' (that is, partyguided, English-speaking communities). However, this is not a trend: the majority of student houses present nationally mixed populations, including several Portuguesespeaking individuals. Both patterns of inhabiting are equally spread over the entire city, just as their effects on gentrification processes (as we will see in the next section).
In an attempt to find student concentrations within urban structures that are different from those of the UK, a group of Spanish researchers coined the term 'vertical studentification' (Garmendia et al., 2011). They stress the role of housing morphology in the impact of studentification: in a landscape of medium or tall buildings, clustering exists only on some floors of some buildings, thus limiting the impact on the neighbourhood. In the case of Lisbon, a mixed model of housing morphology is found: older structures in the city centre, characterised by some single-floor houses and small low-rise buildings (from two to four floors), whilst the Avenidas area has high-rise blocks with more than five floors and several separated apartments on each level. However, the cheap price of leisure activities brings most students to the night-life venues, moderating the effect of house parties and the subsequent pressure on non-student neighbours to abandon the building. Finally, another feature concerning the concentration of students that softens the studentification effect in Lisbon is the lack of development of purpose-built student accommodation (PBSA). These new developments, often associated with processes of new-build gentrification (Hubbard, 2009;Sage et al., 2013), should allow the progressive demise of the private supply of unregulated flats all over the urban territory, considered a 'risky business' for all parties involved (Smith, 2009(Smith, : 1801. However, rental and subleasing through informal agreements (no legal contracts, no receipts, verbal understandings) continue to dominate the market as the main option for exchange students in Lisbon. This type of accommodation is often located in old buildings where the students occupy different-sized flats (from three to six rooms generally). The landlord is rarely a resident in the flat, but is sometimes a visitor in order to control the young tenants and solve the problems generated by such deteriorated buildings. Rita Caeiro, a professional student housing supplier, complains: 'At this moment the great majority of lettings are made informally by private individuals. Unfortunately, until now the authorities have not paid any attention to this situation' (Worx, 2013: 6). According to the report by the Real Estate Consultants, Worx, there is a lack of supply of 10,000 beds in Lisbon, which is provided for by the unregulated market, mostly non-professional, low-capital landlords (Worx, 2013).
Summarising, the UK-centred definition of studentification (HES residential concentrations in specific areas around colleges in the form of HMO, development of PBSA) or even the Spanish adaptation 'vertical studentification' seems to be inadequate for understanding the diversity and fragmentation of student housing in other urban areas (such as Lisbon). As Collins has suggested, 'there are serious limitations to the focus of student geographies on the notion of studentification' (2010: 950). In the following section we go beyond the alleged dependence of student lives on the housing market by providing a portrait of the most important group of international students in Lisbon (Erasmus students). Their transnational patterns of socialisation, consumption identities and migratory experiences are strongly related with the colonisation of new urban areas and practices, in Lisbon's ongoing process of gentrification.

The fragmentation of the studying abroad experience
International students must be recognised as social actors involved in a short-term migration process (King and Raghuram, 2013), which means that their social incorporation in the destination is often mediated by migratory networks, identity issues, and processes of distinction (Murphy-Lejeune, 2002). Foreign students are, above all, in the midst of an experience abroad that involves a process of transition to adulthood (Tse and Waters, 2013) in which they try to shape their lifestyles in a new urban context. In fact, the ability of international students to build their own social worlds, identities, and consumption preferences when living abroad has been recognised as a powerful collective strategy for their incorporation in the destination . According to this vision, international students seem to impact on shifting urban forms in a deep and diversified way through their everyday practices and collective lifestyles as transnational new middle classes living (temporarily) in the contemporary city. As stated before, it is necessary to understand that the importance of international students in prompting processes of urban change is that they belong to a wealthier group of students, and consequently are holders of specific and distinguished lifestyles, when compared with their local peers. This universe of social segregation (expressed mostly in night-life spaces, but also in some apartments) between international and local students is analogous to the boundaries between traditional and nontraditional student lifestyles and identities in Bristol (Chatterton, 1999). In the following subsections we will present the examples of distinctive groups of Erasmus students in Lisbon prompting or joining ongoing processes of gentrification and urban change. These marketing operations spread the prestige and the image of the city through travelling imaginaries converting the urban visitor industry (directed to middle-class tourists, students or migrants) in a central field of activity in the new planetary urbanisation. In this sense, some authors have noted that international students usually choose their academic destination attracted by the leisure activities and the overall image of the city or country they want to travel to (Llewellyn- Smith and McCabe, 2008). Consequently, their sojourn could be classified as 'educational travel' ( Van't Klooster et al., 2008) or 'academic tourism' (Rodrı´guez et al., 2012). Therefore, the local leisure industry, municipal authorities, HEIs and travel operators work together in very similar marketing operations in order to attract a broad audience of young people to the urban environment. As a consequence, young tourists and international students together consume the same institutionally promoted commodities in the form of apartments and museums, night-life venues and coffee shops, retail services and music festivals. Following the tourist approach, international students socialise and develop their everyday lives primarily among themselves (particularly with conationals) and with a minority of local students, mostly former exchange students or English-speaking individuals (Bochner et al., 1985;Waters and Brooks, 2011). In Lisbon, different student associations devoted to orienting and controlling international students' consumption of the city, organise activities and parties from Monday to Sunday, promoting a segregated environment where Erasmus students become a socialising community, similar to the observations of Chatterton in Bristol's traditional students group (1999). The everyday lives of these Erasmus students are characterised by almost daily alcoholic intoxication, some tourist travel to other cities and places of interest during the year, circulation in particular urban districts through bars and clubs that are frequented by foreigners, and an unstoppable fever for socialising focused on other international students and always expressed in English. Local Portuguese students and also alternative Erasmus students -who avoid interacting with them as much as possible -call them 'the typical Erasmus', because their practices correspond to the imaginary forged around Erasmus students. Moreover, there is a gathering place -also promoted by the student associationswhich is central for this group of students: the Erasmus Corner, a gathering spot for foreigners in the most important night-life district in the city: the Bairro Alto.

International students within the tourist city
I like the Corner because you always can meet with somebody you knew in a party the last weekend, or from the faculty, and you just walk to them and start a conversation. Even if they are total strangers it's really easy to get to know new people and maybe finishing the night together in some disco. (Adrian, 23, Germany) Every night hundreds of Erasmus students (and also Portuguese who want to socialise with them, pickpockets, drug dealers and tourists) reunite here -at the crossroads with four bars -to drink something until 3 am, when the bars close and the people go to the discos, in other districts such as Cais do Sodre´or Santos. Adrian went to the Corner for the first time the night he came to Lisbon guided by his flatmates and repeated almost every night for the next weeks, as the starting point of a long night out. After some time, his dense and complex friendship network had reached people from many countries, faculties and neighbourhoods in Lisbon: all English-speaking international students. The Erasmus Corner is a space of representation for the temporary identities, affections and practices shared by this community of (socalled) 'typical' Erasmus students.
But the Corner is not the only place where international students and young tourists consume the same leisure goods. Particularly, it is possible to track down the growing presence of Erasmus in some environments affected by processes of urban change such as the vintage-style night-life venues that are spreading in the formerly run-down Cais do Sodre´district (Nofre, 2013). Likewise, in the recently renovated Mouraria neighbourhood the offer of multicultural sound ambiances in different urban spaces attracts both tourists and other foreigners (Sa´nchez, 2017). For the last 10 years, attracting tourists has been considered a driving force of gentrification processes (Gotham, 2005), especially in Spain and Latin-America, where 'state-led tourism gentrification' was identified as a paramount policy in urban development (Janoschka et al., 2014). In the perfectly equitable case of Lisbon, the investment in cultural heritage, higher education and the tourism industry (through a united strategy of urban marketing) attracts massive flows of visitors, who are often interchangeable in terms of consumption. This process includes the displacement of former inhabitants in particular districts to provide short-term rented apartments for visitors (tourists or international students). Therefore, in spite of being international students they participate in the production and consumption of Lisbon as a tourist destination, favouring the general ongoing process of gentrification.

Alternative exchange students or marginal gentrifiers?
Students' desire to differentiate themselves from other groups by strategic processes of distinction (Bourdieu, 1979) leads them to build complex urban lifestyles in their short-term migratory contexts. In this sense, some students create particular 'universes of belonging' (Cuervo and Wyn, 2014) in opposition to the default Erasmus circuits and overcrowded events directed to foreigners. As critics of the uniformity of 'studentland' (Chatterton and Hollands, 2003), they reject both homogenised international lifestyles ('typical' Erasmus) and same-country segregation (national-oriented friendships), stating, often literally, that they 'aren't the typical Erasmus'. It is possible to distinguish two transnational alternative youth cultures regarding their particular -and spatially localised -'student habitus' (Chatterton, 1999).
The largest and most significant alternative Erasmus culture in Lisbon is the neobohemian. 5 These authenticity searchers are characterised by their attraction for living in old city centre neighbourhoods where they seek 'real contact' and 'familiarity' with the local culture and people. As a consequence, they often live, and go out at night, in areas such as Alfama, Grac xa, Mouraria or Bica, far away from the 'vulgarity' of night-life districts such as Bairro Alto, Santos or Cais do Sodre´where the 'typical' Erasmus and also the vast majority of local students go. 'Neobohemians' identify the smooth rhythm of life of the 'real Lisboa', with their own new-age lifestyles, trying to differentiate themselves both from 'immature' 'typical' Erasmus students and from tourist 'vulgarity'. However, they are actually consumers of Lisbon's cultural commodities, dwelling in the 'typical' and 'authentic' neighbourhoods instead of just visiting them: I love living in Alfama. There is a hidden traditional coffee shop that I discover recently: you can eat something, a very simple and tasteful soup, or drinking a beer in the outside, just like the other neighbours. It's beautiful because it's a calm and peaceful environment. (Lukas,24,Germany) However, when Lukas's family came to Lisbon, he accompanied them through the city as an improvised tourist guide, following the official cultural agenda and sightseeing circuits. Lukas and his circle of friends were all Erasmus students of arts, humanities and languages, living in Alfama and Grac xa, and they came from different European countries. Their night-life habits included going to Miradouros (viewpoints located on Lisbon's hills) and doing botello´n (the habit of buying bottles of alcoholic drinks to share with friends in the street while smoking joints). In our conversations about their preferences for these old city centre districts they always expressed a desire to coexist with the 'genuine' and the 'authentic' elements that they found in these districts. This quest could be attributable to some kind of experience curriculum for their careers. They are the cultural workers of the future, colonising the frontiers of the unexplored city. Considering their low economic capital and their diversity-seeking appetites (Blokland and VanEijk, 2010), these students could be considered 'early' or 'marginal' gentrifiers (Rose, 1984). In Lisbon city centre, lowcapital Erasmus students are participating in this process of marginal gentrification by residing in old non-rehabilitated buildings that have been divided in private rooms, primarily in impoverished, but culturally stimulating neighbourhoods, such as Bairro Alto (Mendes, 2011), Alfama (Malet Calvo, 2013 or Mouraria (Malheiros et al., 2013).
Another important alternative culture of marginal gentrifiers is formed by the 'politicised' Erasmus students. These international students frequent places of militancy, such as assemblies, taking part in local protests and demonstrations, and also supporting international campaigns whilst abroad. From a generational perspective of transnational mobilisations, they are the leading figures of antiausterity and Occupy protests, where these students acquired political consciousness and became involved in politics (Postill, 2014). This is the case of the many Spaniards in Lisbon, who participated in the 'Indignados' demonstrations: I came to my Erasmus after spending several time in the streets, camping out in Madrid's Puerta del Sol, and I came very angry, and this created conflict with my former flatmates. Everything was a struggle: recycling in home, my vegetarianism, talking about politics or the fact that I'm not shave my legs. (Maria,22,Spain) After some time in the default circuits of 'typical' Erasmus students, Maria finally met up with other 'politicised' Erasmus students who frequented spaces of alternative consumption and militancy along with local youngsters. These urban ambiances are concentrated in the deprived areas of Intendente, Anjos and Mouraria, which are multicultural, working-class districts in the early stages of gentrification and still associated with marginalisation, drug-addiction and occasional minor crime. These groups of 'politicised' Erasmus students are often formed of mixed groups of Spaniards and Italians who frequent local, non-tourist and politicised spaces of consumption, and eventually move to these areas to live. When asked for the reasons for moving to these neighbourhoods for the next semester they mention the cheaper accommodation opportunities but, above all, proximity to the marginalised populations with whom they sympathise in the context of the 'austericide': working-class low-income Portuguese, immigrants from Brazil, Africa and Asia, and homeless individuals.
Following Caulfield's arguments (1989), marginal gentrification is a desire-led prelude to freedom, emancipation and social mixing prior to capital investment in a particular deprived area. Marginal gentrifiers such as neobohemian or politicised Erasmus students that have been attracted to particular urban spaces, contribute with their presence to rising rents and eviction processes (Slater, 2006). Thus, these low-income marginal gentrifiers are producing attractive lifestyles that will be consumed -after capital re-investment and urban renewal -by higher social classes.
The transformations of a university town into a creative city Finally, in this limited classification of lifestyles it is important to note those Erasmus students who are very committed to their academic career plan and other formal learning processes: the Erasmus scholar. Whilst other Erasmus students may regularly miss lessons because of their leisure and nighttime activities, these students always attend classes and dedicate most of their time to study and to doing homework after class. As migratory students, their priority is to make the most of their stay by travelling within Portugal, visiting museums and cultural events, and -in some cases -practising sports and languages on a regular basis. Their housing preferences are possibly the most well defined among the students: they often live in student residences within walking distance of their universities in order to maximise their days for studying and related activities. Sometimes, instead of residences, they may live in shared flats with other students but always in a private way, and rarely in noisy central neighbourhoods far from the faculties. Conscientious Erasmus students wake up early and enrol in several activities and courses during the day, also attending dinners and house parties during the evening. Although their presence in Lisbon's international night-life is not unusual they return home relatively early (2 am) and do not go out every day or every weekend, as their peers do.
The same as in my home: I don't use to go out at night. It's funny because this could be seen as a strange behaviour. I mean, not get drunk every night and miss the lessons, but I meet with lots of people like me. I can assure you that there are hundreds of Erasmus out there, in this city, with the same habits as me. (Patryk,24,Poland) Some of these hardworking students would return to Lisbon to complete their studies, enrolling in a Masters or PhD if their Lisbon HEIs encouraged them to do so. Offering programmes to attract international students has become a priority in several countries in order to recruit talent for the national productive network and improve their position in the knowledge economy (Wei, 2013). Attracting international students is one of the main strategies for European HEIs since the 'Lisbon Agenda', which wished to turn Europe into 'the most competitive and dynamic knowledge-based economy in the world' (European Council, 2000). The learning economy and the idea of innovation as the motor for economic change were strongly criticised for being guided by neoliberal principles and authoritarian practices within the European Union (Batory and Lindstrom, 2011). However HEIs still work hard to attract foreigners to universities as one of the most important forms of income (foreigners pay much higher fees than nationals). Continuity of the learning economy and the integration of foreigners in national productive networks is assured by the European Union, which recently launched a directive (2016/801 of 11 May) allowing non-European students to remain in EU territories for 9 months after their studies to find a job or to start their own business.
Municipal authorities have also understood the advantages of keeping international students in the local economy, with the creation of start-ups and business incubators centred on knowledge and entrepreneurship. In the case of Lisbon, the municipal authorities have recently developed a programme to attract international students worldwide: 'Study in Lisbon', which seeks to increase the enrolment of foreigners in the Portuguese Higher Education System and their involvement with Lisbon's knowledge economy. 'Study in Lisbon' is a network of several partners: the HEIs of Lisbon, students associations, city entrepreneurship start-ups, Lisbon's trade association 'Lisbon Shopping Destination' and the Garage Erasmus foundation, an employment-seeking platform directed at former Erasmus students. It is difficult to calculate the amount of international students who return or circulate between their home countries and Lisbon, because of a lack of studies in this direction. However, those who wish to integrate into Lisbon's productive system carry with them images and expectations of a certain urban life. In this sense, 'Study in Lisbon' used a particular 'Technology of recruitment' (Rizvi, 2011) presenting Lisbon itself as an axis of interest for young students, entrepreneurs and researchers, synthesising the role of cities as lifestyle clusters for the attraction of talent: 'Lisbon is a cosmopolitan and tolerant city. Lisboners like to welcome people of all nationalities (.) With sun shining during most of the year and 15 minutes from the beaches, you can enjoy your free time to take a beach bath, do surf, bodyboard or kitesurf' ('Study in Lisbon' website). Therefore, the existence of engaging urban lifestyles is a condition sine qua non for the attraction of talent to knowledge-economy cities, and the subsequent colonisation of this talent by capitalists (Wyly, 2013: 389).
In the previous examples of youth cultures presented in this article, there is a continuous overlap of international students' practices, settings and lifestyles with the processes described in the gentrification literature. The entanglement between student's migratory experiences and youth cultures helps to understand the important role of international students as agents of urban change beyond the narrow view of studentification as housing clustering. In this sense, international students often return to the host country in future years, in the form of tourists, to continue their studies (Masters or PhD), or to start some economic activity -ranging from precarious work to the meditated entrepreneurial start-up of small companies. In all the cases they return with particular middle-class patterns of consumption which, in the rise of the creative city, turn international students into 'apprentice gentrifiers' (Smith and Holt, 2007) whose practices will reconfigure 'the socio-spatial patterns of knowledge-based, post-industrial societies and economies' (Smith, 2008).

Concluding remarks: Integrating demand and supply theories
All these distinct forms of incorporation and consumption in Lisbon are the result of complex interlinking of cultural, national and class-based appetites with the continuous production and renovation of transnational youth cultures. Students' preferences and choices are always mediated by subjective processes of elective belonging that existed before (and beyond) investors' planningeven when finally capital managed to reach the goal of commodifying every single aspect of students' life. The selection of a city or an urban area in which to live and consume is a key element in the construction of the experience abroad, displaying contiguity between housing supply and subjectivity, between socio-spatial capitalisation and place-consumption. Or as expressed by David Ley: 'the interdigitation of economic and cultural competencies and pursuits in the gentrification field makes any statement of monocausality questionable. It is not a matter of whether economic or cultural arguments prevail, but how they work together to produce gentrification as an outcome ' (2003: 2541-2542).
In this sense, the excessive dependence on production-driven theories in the gentrification/studentification literature contributes to concealing the diversity of the social processes that lead to urban change and class displacement. When looked at closely, the lives and cultural pursuits of international students provide valuable clues as to how this interaction between place-makers (investors and new urban classes) could work. An ethnographic study with a group of Erasmus students could serve as an example (Malet Calvo, 2013): In 2008 the owners of a hostel in Lisbon bought the ground-floor apartments occupied until then by a group of alternative Erasmus. Next year, students' innovative practices (installing benches at the patio to socialise and organise parties) and their alternative aesthetic preferences (such as new-age decorations) were identified and developed as commodities for tourism consumption by those owners. It is true that international students are consuming tourist goods, gentrifying some districts, and participating in the knowledge economy that others may have planned for them. However, at the same time they are inventing and spreading new urban lifestyles that only could be colonised by urban investors after their local discovery (which occurs successfully only from time to time). Thus, gentrification as an urban process prompted by international students operates through the simultaneous presence of vital pursuits, economic interests and place colonisation, in particular, and globally interrelated, urban settings. As stated by Wyly, the new conditions of the cognitive-cultural (global) system of production, in which international students are the real core, 'are dissolving the relevance of the sharp categorical distinctions and polarising binaries of the gentrification debates' (Wyly, 2015(Wyly, : 2533.

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Urban Studies 55 (10) Further research needs to examine how students' differentiated habitus -demonstrated in order to become distinctive among their international peers -seems to be encouraging the diversification of their impact on the city. Additionally, ethnographic case-studies with particular groups of students could be valuable in understanding how -in specific settings -the emotional gesture of youth lifestyles can engage with the private economic interest of urban change, together (re)producing the landscape of contemporary cities.

PALOP (Paı´ses Africanos de Lı´ngua Oficial
Portuguesa), meaning: Portuguese-speaking African countries. 2. Municipal institutions calculate HEIs' students counting each faculty separately which leads to these huge numbers, corresponding to 35 universities of different sizes. Only five of them, located in the city, concentrate the vast majority of students. These data and those following are collected from PORDATA, Study in Lisbon Platform, Erasmus + National Agency (Portugal) and Eurostat, 2012. 3. Portugal has been receiving a large number of foreign students from countries where Portuguese is the official language (55%). As a result, in 2012 it was ranked the second European country for foreign students coming from countries with the same language (OECD, 2015). 4. From this characterisation, hereafter, we will not differentiate between the terms 'international', 'foreign', 'mobile' and 'exchange' when referring to the Erasmus students. 5. In this paragraph quotation marks are used to represent the emic language of neobohemian group.