New Puppets in the Old School: The Applicability of Traditional Internationalisation Theories in the Sharing Economy

: Sharing Economy platforms have expanded their operations all around the globe at an unexpected rate. Due to its “asset-lite” nature, traditional internationalisation theories may not be able to fully explain or predict their expansion patterns. This lack of theoretical background puts at risk the phenomenon’s future and stops traditional companies from coming up with a solid plan to compete against platforms. To ease the creation of a Sharing Economy internationalisation paradigm, this paper intends to review the existing research regarding the internationalisation of sharing platforms as well as the applicability of existing theories. Through a systematic literature review, the existing research was reviewed, and afterwards, internationalisation theories and their distinct factors extracted were noted to address the applicability of these within the singularities of the sharing phenomenon. This classiﬁcation of factors was done according to the exiting literature in the ﬁeld. After this research, we can conﬁrm the lack of explanatory power of traditional theories regarding sharing platforms and conﬁrm the insufﬁcient research regarding these operations. We propose a list of factors that should be considered for future research as a guideline for the further development of the Sharing Economy internationalisation theory. Additionally, the factors classiﬁcation is tested upon the case of the internationalisation of Blablacar, the most extensive carpooling network operating, to check if the theoretical and the practical approaches converge.


Introduction
The platform business model has grown both in size and scale dramatically over the last decade, and has contributed to driving up productivity in multiple ways (Evans and Gawer 2016), proving not to be fragile or a temporary notion (Fan et al. 2019). This system has been celebrated by consumers and investors (Wirtz et al. 2019) by achieving an unprecedented rate of global success (Parente et al. 2018), despite not having a clear definition (Botsman 2013;Frenken and Schor 2017;Sundararajan 2014). Instead of focusing on developing and commercializing products, this model concentrates its efforts on creating an efficient and convenient virtual marketplace that connects users and allows them to match accordingly to time, place, and individual preferences (Parente et al. 2018).
With an expected market value of $335 billion by 2025 (Statista 2020) and millions of direct and indirect employees, platforms have become a significant economic force and a global phenomenon (Evans and Gawer 2016). To maximise the payoffs, SE platforms have expanded quickly to other countries, in some cases without taking enough time to evaluate how to adapt their methods and strategies, resulting in mixed results from these internationalisation processes (Kozlenkova et al. 2021). This international expansion has attracted a great deal of attention, but most questions related to these processes still need to be addressed by the literature (Kozlenkova et al. 2021;Parente et al. 2018). Although, in general, the SE is a recent concept, the academic interest in this area is continuously growing (Sassanelli et al. 2019), boosted by the request for answers by traditional companies and the society in general, which are concerned about the legality and fairness of this competitive model (Dunne 2017) and their long-term impact on communities all around the world (Marchi and Parekh 2016).
According to Marano et al. (2020), SE platforms seem to be less challenged by internationalisation-related challenges than traditional companies, and, at the same time, platforms have been said to be able to formulate novel ways of international expansion (Nambisan et al. 2019), extricating themselves from existent paradigms. Although, assessing the size of the sharing sector is difficult (Schor and Vallas 2021). In a survey carried out by the Center for a New American Dream (2014), between 10% and 14% of Americans had participated in a sharing exchange. Regarding Europe, and according to ING Bank's (2015) study, around a third of Europeans consumers have heard of the sharing economy, and around 5% have declared to participate actively on it during the previous year. This same study anticipated the growth that was about to come within the coming years, which was mainly driven by technological innovations, cultural practices, the economic conditions, and the Great Recession, together with the discourses of SE founders and designers (Schor and Vallas 2021). By enacting a new way of work, which offers a more flexible and personalise schedule (Sundararajan 2016), lower entry barriers and a more inclusive environment for people from all types of backgrounds (Zanoni 2019) the SE has expanded all over the world at an unprecedent rate, challenging both, traditional companies, and scholars.
By taking into consideration this information, the main objective of this paper is to review the most prominent international theories, and point out how they can be used to explain the internationalisation processes of SE platforms and where they fail to do so. With this paper, we aim to understand the applicability of traditional theories in the SE and open new research paths to formulate a new custom-made theory that takes into consideration the SE specificities. Therefore, during this research, the following research questions will be addressed: RQ1: Are existent internationalisation theories able to explain the foreign expansion processes of SE platforms? RQ2: How can the SE specific characteristics interfere in the applicability of internationalisation theories?
This study is the first attempt to analyse the applicability of the factors derived from the main internationalisation theories and comes justified by several reasons. First, it presents an overview of the current internationalisation theories and their key factors. Second, by analysing the SE in this context, the relevance of each factor can be evaluated under the perspective of this model, which will allow sifting among those factors which can be useful when explaining internationalisation processes and those which are not. This sieving will confirm if any of the actual theories is fully applicable to this model, and in the opposite case, which factors should be considered when analysing the expansion processes. Finally, by bridging the disconnect between the SE model and the internationalisation theories, we aim to provide a foundation for future research regarding these processes and stimulate this discussion.
To shed light on this theoretical question, the case of Blablacar's internationalisation process was analysed under this new perspective. This platform is the world's leading long-distance carpooling platform, with a community of 80 million drivers, passengers in 22 countries and 600 employees (Mogavero 2020). It contributes to bringing people closer and creating a unique space and has double the occupancy rate of cars, contributing to carbon-saving. Moreover, this platform, among other examples as Lift or Ola, has changed the old-fashioned mobility systems worldwide (Wirtz et al. 2019) without owning any vehicles (Mogavero 2020).
To reach the objectives set, first, both topics are reviewed, and the relationship between them and their most important aspects exposed. Afterwards, these two elements will be combined and analysed in deep to distort the factors according to their applicability. These results will be applied to the case of Blablacar's internationalisation process. Finally, the discussion and the conclusion section will be addressed, going through the principal results, and showing the way for the further advancement of the field.

Literature Review
With the rise of information technology in the late 20th century, the spread of personal computers, mobile communication and location-based services, the global consumption scheme is changing (Kim and Suh 2021). Furthermore, factors such as the abundance of idle capacity, the growing awareness regarding sustainability, and the economic recession, which implies higher unemployment rates, have constituted the perfect environment for the EC to flourish (Cheng 2016;Kathan et al. 2016). This system offers more convenient access and the possibility of gaining profits from underutilised assets (Cheng 2016;Kathan et al. 2016;Parente et al. 2018), and returns, in some way, to the consumption method followed in the pre-industrial era, when people lived in smaller communities and used to share their limited resources thanks to mutual trust and previous experience (Hawksworth 2014).
This phenomenon has been named as: "Collaborative Economy", "Access economy", "Collaborative consumption" or "Sharing Economy", with this last name being the most widely used. Although there is still no agreement on defining this model (Botsman 2013;Frenken and Schor 2017;Lamberton and Rose 2012), it has some characteristics widely agreed among scholars. These include aspects, such as the critical role played by digital platforms (Möhlmann 2015;Munkøe 2017;Stokes et al. 2014;Tussyadiah 2016) or the reputation systems incorporated within them (Allen and Berg 2014;Frenken 2017;Munkøe 2017). In addition, the elimination of idle capacity of goods (Allen and Berg 2014;Richardson 2015), the preference of access over ownership (Dredge and Gyimoothy 2015;Lindblom et al. 2018;Perren and Grauerholz 2015), or the community of peers (Frenken 2017;Hamari et al. 2016;Perren and Grauerholz 2015), that builds up around platforms (Alonso-Almeida et al. 2020;Baumber et al. 2019;Kassan and Orsi 2012), are considered relevant as well.
Due to the lack of agreement when it comes to defining the phenomenon, different classifications have arisen as well. For example, according to Schor (2016), platforms can be classified depending on the platform orientation (for-profit/non-profit), and the type of provider involved (peer-to-peer/business-to-peer). For Frenken et al. (2015), the SE is compound by three elements: a costumer-to-costumer interaction, temporary access, and a more efficient use of physical resources. If only two out of these three elements are present, they no longer consider it SE, but another economic form of exchange, on demand economy (customer-to-customer and access), second-hand economy (customer-to-customer and goods), or product-service economy (access and goods). Oskam and Boswijk (2016) divided value networks in four groups according to two dimensions. From this analysis, open and not-for-profit systems were identified, as well as peer-to-peer market places based on open systems, closed protected systems for the common good (called collectives) and hyperconnected and distributed platforms with a commercial goal (network capitalists). These different definitions and classifications lead to a very disorganised research field as well as to difficulties with collecting and processing information to obtain empirical data, which results in a lack of official statistics (Schor and Vallas 2021).
In general, it could be said that through this system, similarly to multi-sided marketplaces or triadic business model (service enabler-service provider-customer), platforms rely on information technologies to allow different agents to share their assets and to find a substitute alternative to ownership (Parente et al. 2018). The success of this model relies on the strength of this interaction (Kumar et al. 2018). In addition, this shift from bilateral to multilateral relationships allows members to have varying and dynamic roles through their time within the platform (Nambisan et al. 2019). The effects of the SE continues to trigger an intense debate among scholars (de Streel and Larouche 2015), and traditional industries are opening to newcomers which compete with existing companies through different strategies and methods (Russo and Stasi 2016), challenging traditional ways of doing business and changing the global organization of economic activities (Vitkovic 2016).
Due to the virtual nature of the platforms, users access them through web browsers or mobile apps, which means that they can be used all around the world, allowing them to be international "by default" (Shaheer and Li 2020). Although this opportunity is presented, most platforms make deliberate foreign market entry decisions (Stallkamp and Schotter 2019) expanding aggressively and not being conditioned by cultural or economic discrepancies (Parente et al. 2018). However, these internationalisation decisions are often made without much information, making platforms unsure of how to proceed (Coviello et al. 2017), resulting in different degrees of success (Kozlenkova et al. 2021). This quick international expansion has attracted a significant amount of attention (Parente et al. 2018), but this is a topic still to be developed, which could have its foundations in traditional business theories.
International business strategy has been an area of interest for many years, which has contributed to the development of different theories aiming to explain the processes undertaken by companies. Traditionally, these theories were focused on large multinational corporations (Johanson and Vahlne 2009;Mtigwe 2006), but the focus recently has been on the analysis of smaller companies, international new ventures, and born-global companies, as they seem to internationalise faster and differently (Oviatt and McDougall 2005;Smith et al. 2012).
Although the internationalisation research field has increased over the last few decades, literature dealing with the internationalisation of SE platforms is almost non-existent (Parente et al. 2018;Stallkamp and Schotter 2019). This is relevant because traditional internationalisation-related challenges are less relevant for SE firms (Marano et al. 2020), and, therefore, underlying reasons for internationalisation may be different. Due to their nature, there is a need to formulate novel ways of international expansion models (Nambisan et al. 2019), as although traditional theories could be considered, their theoretical assumptions are significantly challenged by this new system (Parente et al. 2018).
From traditional international business literature, three main perspectives can be found aiming to explain internationalisation processes (Table 1) (Akter et al. 2019;Andersson 2000;Burgel et al. 2001). These three domains identify how internationalisation has been explained through previous theories, either by growth and expansion, or though strategies and methods, therefore considering an internationalisation theory any paradigm which study:

Theories Key Assumptions Derived Factors Authors
Resource-Based View of Internationalisation (Firm Level)

Resource-Advantage Theory
Assumes that the international resources of a firm influence the internationalisation of small business Firm's performance Firm's territorial location Barney (1991) Competency-Based Theory

I-Model
Firms start involving in international trade with those countries having psychologically distinct features. Export activities vary for small firms depending on the decision-makers of the firm. The process of decision-making is the key to the process of internationalisation.
Past or present experience Exploration for market knowledge Previous experience and reputation, founders learning and positive behaviour Bilkey and Tesar (1977) Czinkota (1982) Reid (1981 Network Theory of Internationalisation Emphasise personal relationships as the key factor to enter the international market. Personal networking Johanson and Mattsson (1987) Munro and Coviello (1995) Laforet and Tann (2006) The Evolutionary

Approach of Internationalisation
Internationalisation is dependent on contingent on the nature of the knowledge. The quality and nature of knowledge developed by an organization and its deployment are dependent on the institutional settings and social communities where the firm is located.
Quality of knowledge Nelson and Winter (1973) Kogut and Zander (1993)

Process Theory of Internationalisation
The internationalisation process of a firm is initiated in a reactive mode in response to unsolicited export orders. Spontaneous international orders provide entrepreneurs to accumulate knowledge of internationalisation and learn both their organization's capabilities as well as international market needs.

International orders Experience in international transactions
Firm's perception Vernon (1966) New Venture/Born Global Firm's Theory of Internationalisation Economic Perspective: The economic perspective, based on Smith (1776) and Ricardo (1891) conceptualise internationalisation as an independent phenomenon for profitmaximization, and places the firm's distinctive advantage central to internationalisation and conjectures rationally (Seifert 2010).
Resource-Based View Perspective: This theory, initially proposed by Penrose (1960), and actualised several other times by authors like Wernerfelt (1984) and Barney (1991), became the dominant paradigm in strategic planning (Barney et al. 2001) and later, an influential approach in internationalisation research (Peng 2001). Through this theory, the internationalisation of companies is explained as an adaptive response to environmental complexity, with the aim of gaining a competitive advantage by organizing the resources, skills, and routines (Teece et al. 1997).
Behavioural Perspective: Behavioural theories of internationalisation appeared as an alternative to the economic view of internationalisation (Akter et al. 2019). The central assumptions of behavioural theories of internationalisation are: (1) path dependency; (2) goal complexity; (3) contextual contingency; and (4) weak rationality requirements (Seifert 2010). This perspective has provided a solid background for new perspectives on understanding internationalisation.

Methodology
The qualitative research here has involved a systematic literature review (Grant and Booth 2009;Petticrew and Roberts 2006;Tranfield et al. 2003) to investigate the previous research analysing the relationship between the SE and the internationalisation of the platforms. The main goal of this step is to check if there is any specific research that analyses the internationalisation of SE platforms, and if so, what has been said about these processes.
The search strategy was based on the bibliographic database Web of Science (WoS) Core Collection, as it is the most widely accepted and frequently used database for the analysis of scientific publications (Castillo-Vergara et al. 2018;Dzikowski 2018;Guerras-Martín et al. 2020;Yang et al. 2013).
We identified the research area for the systematic review and studied the scope and objectives, setting the SE as the central concept. Afterwards, we determined the inclusion and exclusion criteria. All of the articles and reviews in the database containing the keywords "sharing economy", "collaborative economy", or "platform economy" were retrieved. This approach yielded a total of 2564 results. The sample was downloaded and reviewed to remove duplicates and confirm their fit within the model. The authors undertook this process manually, including 1898 papers in the final database. This search was conducted in April 2021.
For this specific research, a subgroup of publications was analysed, selecting from the previous sample those articles that relate the sharing economy with the internationalisation processes, including those papers studying specific cases. Again, the documents were individually reviewed by the authors to confirm their fit within the topic. In addition, selected references from the articles identified were carefully screened for other relevant studies.
After the initial query, the sample was personally revised by the authors to eliminate non-related papers and possible duplicates. Once this step had been undertaken, the remaining papers were analysed in depth. Several new articles were included because they appeared in the bibliography of some of the selected papers and dealt with the topic in question. Finally, nine papers were identified that studied the relationship between the SE platform and internationalisation ( Figure 1). These nine studies can be found in Table 2.
The next step was analysing which of the factors extracted from existing internationalisation theories can be used to explain the internationalisation process of SE platforms. First, the internationalisation theories were examined, and their most representative factors noted to study. Afterwards, these factors were individually addressed from a theoretical point of view to analyse if, according to previous literature regarding the SE, its characteristics and processes, each individual element could be used to explain the international expansion activities of platforms. In order to address the applicability of the factors, and due to the lack of literature regarding these specific processes, general literature regarding the SE was used, relating the internationalisation factors extracted with the closest existent literature. The reasoning behind the classification of each element is explained in detail in Sections 4.1-4.3, and summarised in Table 3, where the factors, their suitability and the literature supporting the classification are presented. After this process, the resulting division of factors was tested on the case of the internationalisation process of Blablacar, to check if the theory driven classification was true in a practice driven example.
Adm. Sci. 2021, 11, x FOR PEER REVIEW 7 of 24 and exclusion criteria. All of the articles and reviews in the database containing the keywords "sharing economy", "collaborative economy", or "platform economy" were retrieved. This approach yielded a total of 2564 results. The sample was downloaded and reviewed to remove duplicates and confirm their fit within the model. The authors undertook this process manually, including 1898 papers in the final database. This search was conducted in April 2021. For this specific research, a subgroup of publications was analysed, selecting from the previous sample those articles that relate the sharing economy with the internationalisation processes, including those papers studying specific cases. Again, the documents were individually reviewed by the authors to confirm their fit within the topic. In addition, selected references from the articles identified were carefully screened for other relevant studies.
After the initial query, the sample was personally revised by the authors to eliminate non-related papers and possible duplicates. Once this step had been undertaken, the remaining papers were analysed in depth. Several new articles were included because they appeared in the bibliography of some of the selected papers and dealt with the topic in question. Finally, nine papers were identified that studied the relationship between the SE platform and internationalisation ( Figure 1). These nine studies can be found in Table  2. The next step was analysing which of the factors extracted from existing internationalisation theories can be used to explain the internationalisation process of SE platforms. First, the internationalisation theories were examined, and their most representative factors noted to study. Afterwards, these factors were individually addressed from a theoretical point of view to analyse if, according to previous literature regarding the SE, its

Results from the Applicability of Selected Factors from Internationalisation Theories within the Sharing Model
The first step of the process was searching for papers analysing the internationalisation of the SE. Table 2 presents the final sample of documents obtained after applying the different criteria stablished.
After corroborating the statement about the scarcity of research regarding the internationalisation processes, selected theories were tested upon the sharing model. Table 3 shows a list of derived factors from internationalisation theories (included in the last column of Table 1) and their expected suitability to explain the internationalisation expansion of SE platforms according to previous literature of the field. Some of these factors were grouped with other similar ones. In order to make this classification, and due to the small amount of specific literature regarding the internationalisation processes, general literature about the SE field was used. Therefore, previous literature was checked to analyse how each specific element would interact the SE characteristics and attributes, and therefore infer if, at the time of international expansion, that element would be relevant when explaining the methods and decision behind the operation.

Non-Influential Factors
The main goal of platforms is to provide a common land for users, therefore, platforms do not undertake any production activity nor generate costs further than those which arise from the platform maintenance and responsible for this. By being "asset-lite" (Parente et al. 2018) and relying upon their users' goods to provide their service, platforms do not benefit from any cost reduction by operating in one or another location, neither general labour nor transport costs (Anwar 2018;Frenay 2018;Parente et al. 2018;Wirtz et al. 2019). This implies that the search for lower production costs is not as influential for sharing platforms as it is for traditional companies.
By acting as an intermediary between users, platforms do not have suppliers, so they cannot be influenced by the chance of being an intermediate supplier. According to Wirtz et al. (2019), platforms have disintermediated industries by facilitating people to transact directly with one another in unprecedented ways (Caldieraro et al. 2018). As platforms do not focus on developing or commercializing products, but in creating an efficient marketplace to connect users (Parente et al. 2018), the product's heritage value cannot influence the internationalisation decision.
The relationship between firm performance and internationalisation does not seem relevant, as platforms usually do not wait to have a solid performance in the home country before moving to others (Kozlenkova et al. 2021;Ochieng and Takawira 2020). Due to their specific characteristics, platforms will be influenced to a lesser extent by risks (Brouthers et al. 2016) than traditional companies. This lack of relevant risks could be a critical factor in the accelerated internationalisation process, as they can start operating internationally before any company following a traditional business model could (Parente et al. 2018). This lack of risks and the flexibility inherent to the model (Nambisan et al. 2019) places the firm's territorial location as a less relevant factor when making the internationalisation decision. Digital businesses have implied the "death of distance" (Cairncross 2001) due to its ease when expanding through the use of the internet and technologies. Hence, the territorial location is not an inhibiting factor anymore.
The exponential growth of the SE (Frenay 2018) supposes that this model is known and present almost anywhere, so platforms can, at least, foresee the success opportunities of their business in different locations. This fact can be considered advantageous as platforms do not need to adventure in new countries to explore and increase their market knowledge. From the begging, platforms can know the market conditions or have easy access to locals who can provide with knowledge (Ochieng and Takawira 2020), which influences speeding up internationalisation processes (Kozlenkova et al. 2021) and the establishment in said location. By being able to access local knowledge, the information or experience accumulated by platforms before the establishment in new countries is not much. However, this factor does not hinder their expansion intentions. Regarding this factor, older platforms could have a slight advantage over younger competitors (Anwar 2018).
The SE has proved that it is neither a tendency nor a temporal phenomenon (Fan et al. 2019). Although its popularity has increased over the years and it is possible to find platforms almost anywhere, internationalisation decisions are not based on demands of potential users in other locations or client chasing strategies. Instead of basing their decisions on international orders, platforms seek opportunities to broaden their business portfolio (Anwar 2018). As previously indicated, the risks assumed by platforms are, theoretically, smaller than those assumed by traditional companies, so the risk perception is lower as well (Nambisan et al. 2019). The "asset-light" condition of these platforms reduces the size of the investment needed to enter new markets, allowing a rapid expansion and limiting asset exposure (Marano et al. 2020). Due to the novelty of the SE field, and although the industry is in different life stages depending on the country to be analysed, neither of them can be considered to be in a mature or declining stage, so the main reason behind the internationalisation of platforms is not a decline in the local demand, but the opportunity to keep growing in potentially successful locations (Liu and Chen 2020; Razeghian and Weber 2019).
Finally, platforms businesses are more flexible than traditional businesses. This characteristic allows them to adapt quickly to changes (Wirtz et al. 2019), therefore not being so much influenced by other competitors' decisions. Although there is an increasing number of multi-country platforms (Kim and Suh 2021), there is still a significant proportion of non-internationalise equally successful ones, so, therefore, it cannot be said that platforms are internationalizing because of an adaptive response to challenging environments, but rather are deciding on their own when, where, and under which conditions they want to internationalise (Parente et al. 2018).

Influential Factors
Due to the nature of the operation carried out through SE platforms (Parente et al. 2018;Wirtz et al. 2019) the internationalisation is fundamentally different from traditional companies, mainly in terms of speed, scope and territorial expansion (Frenay 2018;Marano et al. 2020). Instead of offering any product or service, these platforms aim to create a shared virtual space to connect people with similar needs (Alonso-Almeida et al. 2020;Hamari et al. 2016;Stokes et al. 2014). This mainly digital nature allows platforms to expand their operations within territorial spaces almost from creation (Shaheer and Li 2020).
As commented previously, the novelty of the SE places it in the first stages of its lifecycle, although it can vary among these first stages depending on the territorial location. This growth has led platforms to invade markets (Frenay 2018) and enjoy rapid global growth opportunities (Marano et al. 2020). This rapid growth has been influenced by the platform's characteristics and its way of achieving competitive advantages. According to Chasin et al. (2018), these competitive advantages depend on having a big community of users, both on the supply and the demand side, and therefore create interconnections among partners (Nambisan et al. 2019). The more local users that both sides of the network have, the more attractive it will be for new users (Stallkamp and Schotter 2019). Since sharing platforms do not possess any other source of competitive advantage, as difficult to imitate assets (Parente et al. 2018), this generation of a network of users is a critical factor for their internationalisation. In the same way, platforms generate value by leveraging the resources and users of communities, lowering transaction costs and fostering trust and ecosystem governance (Wirtz et al. 2019). According to Rogers (2016), these platforms deliver value differently from traditional businesses, achieving a differentiation degree that translates into a higher perceived value by users (Kozlenkova et al. 2021).
The growth experienced by platforms has, on some occasions, has been hindered by different barriers, as legal and regulatory problems (Dunne 2017;Vitkovic 2016). These laws can affect platforms and the experience of users (Kozlenkova et al. 2021) as they can see their experience modified due to these limitations. In addition to the legal barriers and the reaction from local competitors (Felländer et al. 2015), platforms need to take into consideration other kinds of barriers as trust, sustainability and societal issues or institutional concerns (Anwar 2018;Kozlenkova et al. 2021;Marano et al. 2020). Regarding this last aspect, factors related to the local institutional conditions affect the platforms' internationalisation decisions (Tsukanova 2019). According to Uzunca et al. (2018), countries with lower levels of institutionalization may be more accessible for platforms to enter and achieve power due to their lower barriers and the ease for platforms to gain society's approval.
Finally, as it has been stated before, over recent years, the SE has experienced exponential growth in terms of users, platforms and industries where it is possible to find collaborative alternatives (Anwar 2018). This global tendency of access preference has sped up the internationalisation process (Frenay 2018), and platforms have become an important economic force (Evans and Gawer 2016). Together with the better exploitation of market imperfection by platforms (Parente et al. 2018;Razeghian and Weber 2019), this fact has created a perfect environment for the SE to grow and expand their operations all over the world.

Potentially Influential Factors
There are some other factors that, while not being indispensable, may help explain platforms' internationalisation decisions. The quick speed of growth within the SE has benefited most platforms, although it has brought some challenges. Due to this speed, platforms willing to internalise have felt the urge to take quick decision, which on some occasions has been an advantage and in other a drawback. According to Ochieng and Takawira (2020), those first-mover platforms have faced many disadvantages as competitors were aware of their decisions to avoid their errors and take advantage of their knowledge. On the other hand, some platforms were willing to take these risks, as the benefits of first movers outweigh the disadvantages (Felländer et al. 2015). However, wishing to enter a location as quickly as possible, platforms can ignore their lack of knowledge regarding the local conditions (Frenay 2018) or forget to adapt their strategies to the country-specific factors. These facts may be the main reason for many unsuccessful operations (Kozlenkova et al. 2021), becoming, therefore, a relevant factor to take into account when expanding operations cross-borders.
In order to avoid as many threats as possible, platforms might tend to internationalise in those countries in which they can achieve context-specific advantages (Nambisan et al. 2019) and where the local conditions are similar to those faced in previous countries (Kozlenkova et al. 2021). The study of demographic characteristics and usage patterns can help determine the most advantageous conditions for the SE to flourish (Kumar et al. 2018;Shaheen et al. 2017) and decide future destinations based on said data. Among these conditions, the local language may be a determinant factor for some platforms. They may find it easier to enter countries with similar languages (Ochieng and Takawira 2020;Stallkamp and Schotter 2019). Meanwhile, this factor may not be relevant for other platforms, as platform software can be translated easily without incurring high costs (Marano et al. 2020).
Although the SE is characterised by their aim for growth and expansion (Anwar 2018), their past experience can condition this expansion, for example, regarding the speed (Ochieng and Takawira 2020) or the evaluation of local conditions (Kozlenkova et al. 2021) in order to avoid previous errors or repeat successful strategies, as for example collaborations. By complementing their system with complementary asset provides, for example, insurance companies (Mogavero 2020), platforms can manage their ecosystem and assure a sufficient number of users on both sides (Parente et al. 2018) as well as achieve an excellent knowledge about local conditions (Ochieng and Takawira 2020). Furthermore, these alliances may influence internationalisation decisions by encouraging platforms to expand to those countries where their partners are present or a higher chance to reach agreements.
Finally, when talking about factors related to the entrepreneur/manager figure, contrary to the born global companies, which mainly depend on the entrepreneur will to internationalise (Bouncken et al. 2014;Kuivalainen et al. 2012), there is no evidence of SE platforms being highly dependent on the entrepreneur goals and perceptions. In contrast to traditional business, platforms require a management team that facilitates a strong network connection, controls all resources orchestration, and fosters liquidity and quality matching (Wirtz et al. 2019). Rather than being dependent on the manager's skills, orientation, perception, or know-how, platforms seem more motivated by external factors, such as the popularity of the sharing model in the target country, government decisions, or population characteristics (Ochieng and Takawira 2020).

The Applicability of Traditional Internationalisation Factors to Platforms: The Blablacar Case
Blablacar (established in France in 2006) is an online platform offering carpooling services, connecting people who need to travel with drivers who have empty seats (Cruz et al. 2018). Blablacar posts itself as the world's leading carpooling community which enables low-cost city-to-city travel by connecting people with drivers going the same way. This platform has 90 million users and is present in 22 countries, with 25 million travellers per quarter (Blablacar 2021), and by combining their ability for identifying share ride opportunities with the SE growth, they have come up to an efficient and popular system. By merging social media with a reservations platform, a feeling of trust and safety was achieved, contributing to the company's establishment (Shaheen et al. 2017). With the vision of bringing fairness, freedom, and fraternity to the world of travel, this platform has revolutionised the mobility sector in Europe.
Blabacar's main business relies on providing a common land for people who have free seats in their cars and people wishing to travel (Mogavero 2020), offering a trendy and innovative product. This new consumption alternative did not only offer a better value in economic terms, but it did also rely on a more sustainable and environmentally friendly option (Font and McCabe 2017), addressing two highly requested topics by users. Due to its recent appearance, both the SE and Blablacar can be considered to be in the growth stage of their life cycle, or nascent market (Casprini et al. 2019), characterised by growing demand and by the expansion of platforms (Klepper 1997). This is the general situation, together with the high aggregated value this alternative has achieved by granting access to goods which, otherwise many users could not access it, has meant that Blablacar has achieved a competitive advantage and a product differentiation resulting from the big and efficient global network of users (Casprini et al. 2019). By achieving a balance between the supply and demand of car seats, the platform reached a point of efficiency in which they believed they had a product that could be successful in different countries (Shaheen et al. 2017). Therefore, by relying upon factors, such as the nature of their product, their stage along the life cycle, or their competitive advantage achieved through the superior value of their product and the network of users created, Blablacar decided to take a step toward internationalisation.
As pointed before, the use of technological means and the mainly online nature of platforms suppose that their cost structure is fundamentally different from traditional business, implying lower costs associated with internationalisation processes and lower operating costs (Gilibert and Ribas 2019). Although Blablacar has been expanding into different countries, their headquarters have stayed in France, their home country, complemented with regional offices in some specific settings to provide users with a close, knowledgeable contact according to their location in the globe, and constituting this with a corporate strategy (Aversa et al. 2021). By establishing their offices where most needed are, instead of where the lower costs are located, in operating, labour, and transport terms, the platform is proving that their internationalisation steps are not toward lower costs but towards better and more efficient service for all agents involved and a wider range of options for their users.
At the moment of the first internationalisation, the number of users and car seats offered in France was still rising (Shaheen et al. 2017). Although the platform was not facing a decrease in their numbers, the generalization of the SE tendency along different countries was a growth opportunity, as although there was not an explicit request for these services, there were countries that presented an ideal set of circumstances that favoured Blablacar's business model implementation (Zalega 2020). Due to these being their first steps towards the international expansion, neither the platform nor the management team, which was more focused on programming and web services (Blablacar 2021), had enough accumulated experience or knowledge about the foreign markets as to be influenced when making decisions, an aspect which change as the platform gain experience and started following a quicker internationalisation rhythm. Although before undergoing the first expansion, Blablacar waited until having a solid performance in their home country, after this first expansion, the pace becomes quicker and the performance less relevant, which fits in with the idea of a gradual "foreign gateway market" followed by quick internationalisation decisions (Ochieng and Takawira 2020).
As shown in Table 4, in the beginning, Blablacar expanded its operations in close countries, which have a greater chance of having similar demand structures and socio-economic conditions. It could be said here that, in this case, they are following an incremental internationalisation. By aiming at this, the process could be smoother, and the challenges faced less demanding (Kozlenkova et al. 2021). Even though each country has its particular institutional conditions, by expanding into countries which are not only neighbours and therefore similar in cultures, but also into countries which operate under similar institutions, as the European Union, Blablacar was able to design an expansion strategy which could be applied in several countries at the same time. As the platform expanded into different countries, the virtual space was translated into local languages, facilitating its adoption by users (Blablacar 2021). Although these factors had a higher relevance at the beginning of the internationalisation process, as Blablacar acquired experience, they began to lose importance, and the platform expanded its operations into additional locations and different cultures.  By being one of the pioneering platforms in carpooling of Europe (Mogavero 2020), Blablacar benefited from some monopolistic advantages, as their early start provided them with some years of experience and accumulated knowledge, which allowed them to take advantage of market imperfections and create a network of users who, although having alternatives, would still rely on their platform. To keep their users loyal and stay ahead of possible changes in the industry, Blablacar started building relations with different agents to offer complementary products to their main one. The most well-known one is their collaboration with the insurance company Axa (Gassot 2017), which oversees covering any incident that arises during a trip among members of Blablacar. This partnership allowed the platform to start charging a fee to every transaction made between users, which percentage changed according to the length of the trip and the anticipation of the booking (Mogavero 2020). Although this measure was controversial among users, Blablacar justified it with the new incorporation of the insurance service, which added an extra safety point to the service.

Date of Internationalisation
Apart from this, additional services were added to Blablacar recently: buses and soon trains. By doing this, the platform is not only securing their innovative company image, which assists on renew themselves and boost their competitive advantages (Calabrò et al. 2016) but also fulfils the same need, travel from one place to another, by different means. This helps to reach a higher potential market share, and therefore building an ecosystem of services for the community (Gassot 2017). These new operations and the previous ones and the internationalisation processes have been funded through funding rounds, the most recent one in April 2021. This funding round secures financial stability to the platform to keep working toward their main goal, facilitate mobility between places with shared transportation (Dillet 2021). This compatibility strategy can lead into a new phenomenon and influence on the travel mode choice of urban residents (Lu et al. 2019).

Discussion
After analysing the case of Blablacar, we can say that traditional internationalisation theories cannot fully explain the process undertaken by platforms. In this specific case, the analysis of the extracted factors resulted in the expected results, with some exceptions (Table 5). Blablacar started its international expansion process in countries with a small psychic distance, expanding later into more distant ones (Gassot 2017). This can be explained by the fact that the platform's home country is located in the middle of the European continent, which places them in an ideal location to expand their processes into several neighbour countries at the same time. Contrary to expectations, in this case, the platform's performance was a key factor for the first internationalisation process (Shaheen et al. 2017). However, it lost most of its value as the expansion consolidated and Blablacar started operating into more countries. Finally, although according to the co-founder and CEO, the actual strategy of Blablacar is focusing on their actual operating countries instead of keeping expanding their activities (Dillet 2021), given the funding data and the growth expectancies, this platform keeps positioning itself as the leading carpooling company of Europe and a referent company in the mobility sector in general. Previous literature had already acknowledged the lack of research regarding the internationalisation processes within this model (Stallkamp and Schotter 2019) and the need to formulate a new theory due to the different challenges faced and methods followed by sharing platforms (Marano et al. 2020;Nambisan et al. 2019). This paper has corroborated these statements by verifying that none of the existing theories can be fully applied to the SE model. Sharing platforms share some attributes of ibusiness (Brouthers et al. 2016) and triadic business models (Ochieng and Takawira 2020), reflecting on aspects, such as their quicker international expansion (Parente et al. 2018) or the strength of the interaction between users (Kumar et al. 2018), which significantly influence the success of the business model.
When analysing existing internationalisation literature, two big approaches can be found: the gradual internationalisation and the born global (Paul and Rosado-Serrano 2019). Their main difference is that, while the former says that companies will internationalise in countries closer in proximity to the domestic market in terms of physical distance (Johanson and Vahlne 1977), the latter are created to do global business from inception, internationalizing within three years of founding and generating at least 25% of the total sales in foreign countries (Knight and Cavusgil 2004). Some scholars (Gardinni et al. 2021) suggest that the SE would fit better in the born global model due to their digital nature, asset-free nature, and quick expansion. Although this is a real possibility, more empirical research will be needed to check if platforms fit within this model, as, for example, born global firms are said to need managers with a strong international orientation, which drives them to develop better competitive advantages both in goods and technology (Knight and Cavusgil 2004).
Sharing platforms generate competitive advantages by creating networks of users and facilitating transactions among them, which implies that the bigger the size of the community, the greater value the platform will generate and the more attractive it will be for new users (Stallkamp and Schotter 2019). This suggests that factors related to local culture, features of markets and government positions, and institutionalization factors may affect more of these processes than those factors related to internal aspects of platforms (Razeghian and Weber 2019;Uzunca et al. 2018;Wirtz et al. 2019). On the other hand, factors related to production factors, like transport or labour costs, lose almost all their importance because of the asset-free nature of platforms and the opposite cost structure they have compared to traditional companies (Anwar 2018;Frenay 2018;Kozlenkova et al. 2021;Parente et al. 2018). In the middle of these two extremes, some factors may play an important role for some platforms. Among these factors, some like the relationship with foreign partners (Mogavero 2020;Ochieng and Takawira 2020;Parente et al. 2018;Wirtz et al. 2019), local languages (Marano et al. 2020;Mascareñas Pérez 2011;Stallkamp and Schotter 2019) or the monopolistic advantage achieve by platforms (Anwar 2018; Stallkamp and Schotter 2019) can be found. Contrary to born global companies, in sharing platforms, the role of founders and entrepreneurs is not as determinant in the internationalisation of the company (Wirtz et al. 2019). Through the analysis of these factors, RQ1 was answered, and the applicability of current internationalisation theories was addressed.
Regarding the development of a future theory that addresses the internationalisation processes of SE platforms, considering their singular nature, and as a response to RQ2, it will need to include factors regarding aspects such as the nature of the products/services offered, the level of development of the SE in the location, or the value creation method followed individually by platforms. It should also consider the importance of local conditions, from the social characteristics to the institutional constraints and the technological development of the country or the acceptance towards the online operations. On the other hand, factors related to the production or distribution of goods should be relegated to the background.

Conclusions and Future Research Opportunities
The SE has proved to be more than a temporary trend and is challenging companies from all around the globe (Parente et al. 2018), while becoming a significant economic force at the same time (Evans and Gawer 2016). Due to its specific characteristics, traditional internationalisation theories, which are mainly centred on production and distribution factors, can only provide a partial explanation of why, how, and when sharing platforms internationalise. Therefore, further research within this field is required. This paper has analysed the potential applicability of existing internationalisation theories in the SE by extracting the most relevant factors of each theory and studying their applicability taking into consideration the singular characteristics of the sharing model. By extracting these factors and studying their suitability, a detailed picture of the applicability of each theory is provided, which will assist scholars when formulating a new theory adapted to the set of characteristics of these platforms. It must be considered that the classification of these factors has a theoretical focus, and it is based on previous literature of the SE field, so when applying them to real examples, some of the factors may act differently from expected. Another limitation of this research comes from the set of internationalisation theories selected and the derived factors, which could be complement with more theories regarding growth strategies. It should be considered as well that the SE is in constant change and, therefore, research must evolve as platforms do, so what is applicable today, may not be tomorrow. This fact, instead of being a daunting factor for scholars, only encourages the constant development of new research.
In line with the previous statement, the academic implications of this paper come from the fact that, from a theoretical point of view, the reviewed internationalisation theories do not seem to be sufficient when it comes to explain the geographical expansion of sharing platforms, therefore confirming what other authors said previously (Marano et al. 2020;Parente et al. 2018;Stallkamp and Schotter 2019). Although theories cannot be fully applied, some of their more relevant factors seem to influence internationalisation decisions of platforms more than others. By listing the relevant factors, some guidelines are provided for the future development of a theory which can address in a better way these expansion processes. This theory should consider aspects such as the value creation model of platforms, the barriers to trade to face or the institutional conditions. By providing this breakeven point, we expect to foster research regarding the SE in general and their expansion process in specific. This research would not only be helpful for academics researching this topic but also managers of platforms and traditional companies. The former would be able to count on guidelines regarding the steps to follow to have a smooth internationalisation process within the inherent risks of this strategy and achieve a better rate of success. The latter would have been able to have more information regarding the most recent threat to their business model, and the environmental factors that could make their market attractive for sharing platforms. Therefore, they have a more room to manoeuvre when taking steps toward their answer to these questions and doubts raised toward their systems. This paper will also help those reluctant economic entities to realise that the SE is more than a temporary trend and that platforms could pose a problem to their business, as they do not only compete among platforms, but also with their models (Dunne 2017). Finally, there are some governments which are not sure about how to regulate and deal with the SE (Rifkin 2000;Vitkovic 2016) and are delaying this regulation on the grounds that this phenomenon may be temporal. This research can help them realise the international potential of the SE and urge them to look for solutions which accommodate all the implied agents.
To further develop the research field, scholars should analyse in depth the operations already taken by platforms, looking at the previous and posterior data, at the industry involved, at the specific market characteristics, as well as to the reaction of competitors, both from the sharing and traditional field. This research should count on the platforms' managers collaboration, which will assist in obtaining obtain empirical data, testimonies, and motivations, and therefore, count on a more extensive amount of information coming from different sources.