Sharing is an act intrinsic to humanity, which gains sharing consumption status with internet access (Belk, 2014b). Based on the idea that sharing suggests alternatives such as market exchanges with collections (sale and rent, for example) and free items (donations), for Belk (2007) sharing would be the action and/or process of distributing what is ours for what others can use. Similarly, it refers to the action and/or process of receiving something from others so that it can be used. Thus, sharing involves different situations, occurs with or without profit, with or without the exchange of property, and includes a set of tangible and intangible resources (Belk, 2014a).

The debate about the real frontier between pure sharing and its derivations causes the emergence of different views that do not corroborate the composition of a unified concept for SE. There are several ambiguities and confusions in the use of the sharing principle (Belk, 2014a), which generate variations in the use of the term (Burnett, 2014; Demailly & Novel, 2014; Frenken & Schor, 2017). These variations are identified when it is seen that different authors explore terms with different concepts. However, in general, the definitions involving SE are not contradictory in nature, but distinct in scope and breadth of the elements that compose it (Allen & Berg, 2014).

SE emerged around 1990 in the United States (Botsman & Rogers, 2010; Olsen & Kemp, 2015; Schor & Fitzmaurice, 2015), contributing to the vision in which sharing and exchange between peers has its roots in American culture (Burnett, 2014). It is believed that the economic crisis of the 2000s created a process of distrust in outdated technological concepts, fostering new technological, economic and social approaches (Botsman & Rogers, 2010; Heinrichs, 2013; Schor, 2014). In this context, the SE emerges that grows and gains global amplitude in the world economic crisis observed in 2008 (Belk, 2014b; Schor, 2014).

Amid its growth, agents or peers on the consumption side of SE, called user peers, seek to reevaluate what is, in fact, valuable, considering views about having or simply having access. Despite the intense debate, there is still no united concept of SE (Cockayne, 2016; Demailly & Novel, 2014; Frenken & Schor, 2017). The term Sharing Economy is accepted as generic and capable of representing several meanings (Frenken, 2017; Heinrichs, 2013; Sundararajan, 2016).

SE is considered a new business modality in the light of the traditional economy, as it is characterized by the sharing of assets classified as tangible and intangible, acts in the reduction of intermediaries, and is able to improve direct connections between the different agents (Belk, 2014b; Carfagna et al., 2014). Additionally, Botsman and Rogers (2010) affirm that SE is based on the sharing of idle goods and services, which can occur free of charge or in a remunerated way. For that, it is necessary: the generation of value (monetary and non-monetary) from the exploration of idle assets; the valuation of peers on the supply side, whether companies or not, from an economic and social point of view; benefit peers on the demand side with the ability to obtain products and services more efficiently, being able to generate only access and not necessarily ownership

Botsman and Rogers (2010) corroborate with the SE literature in a broad perspective, which address both supply and demand side (i.e., production and consumption). In addition, we can see social and behavioral fundamentals in the SE capacity to act in scenarios composed by multiple economic agents, such as public and private initiatives. The transactions involved in SE, according to Rustrum et al. (2014), include buying and selling, rent, loan, simple exchange or even the gift-giving exercise. Botsman and Rogers (2010) are more comprehensive about SE transaction and claim that different modalities exist, such as sharing, rent, loan, donation, exchanges and even barter (Pereira & Silva, 2018; 2017).

Therefore, SE is considered the result of the union of three economic trends: the second-hand economy, the economy of products and services and the economy on demand. Such configurations cover different consumption models of SE, such as P2P consumption, whose role of a mediating company is eliminated, the consumption of underutilized goods, when the concept of circular economy acts in the optimization of resource use and, finally, the consumption without the exchange of ownership, in which access is more important than ownership (Frenken, 2017).

The consultancy Altimeter (Owyang, 2016), as well as Botsman and Rogers (2010), considers that SE results from the combination of three drivers or groups of factors: social, bringing an increase in population density, the search for sustainability and altruistic actions); economic ones due to greater financing flexibility, access being more valuable than ownership, monetization of different types of idle assets and increased investments dedicated to collaborative projects) and technological ones (marked by the growth of social networks, the diffusion of mobility with the use of smart and interconnected devices and the improvement of the payment system through the internet).

In a similar way, there are approaches that define SE as a system promoted by the connection of economic, social, and environmental factors (Daunorienė, Drakšaitė, Snieška, & Valodkienė, 2015). As indicated by Krupinsk (2015), in SE there are different roles that can be identified for both individuals and companies: providing products or services, fostering the market, or providing digital platforms. Thus, based on the roles, relationships can be observed: those between peers (Peers to Peers - P2P), companies - pairs (Business to Peers - B2P), between companies (Business to Business - B2B) and in the triangulation pairs - companies - peers (peer to business to peer - P2B2P) (Glind, 2015).

The non-uniformity observed in the concepts/definitions, elements, nomenclature, and performance of the economic agents involved in SE, also occurs in their taxonomies. That is, different taxonomies are observed based on different criteria such as the orientation of the digital platforms used - profitable and non-profit or in the market structures planned and already mentioned - P2P or B2P (Schor, 2014). Moreover, there is a classification oriented according to collaborative activities (Botsman & Rogers, 2010). Considering these arguments and based on the discussion presented by Pereira e Silva (2018), it is understood that there must be a search to advance in studies on sharing economy. Thus, CE is defined as:

A socio-technical business model (which includes economic, social and technical elements), that is capable to promote shared access to goods, services, data and talents, through a hybrid market model, which travels between ownership and donation, of transactions between peers, normally supported by digital platforms.

Following this definition, we have that the socio-technical approach of SE and must consider both the relationships between the actors, as well as the digital technology used to promote the distribution, sharing, reuse, and other forms of the transaction of excess capacity of assets. The use of this definition involves semantic derivations (other concepts) and allows our research to increase the expected results. Figure 1 proposes a scheme of the proposed concept of SE, and accepts its umbrella condition, in which its main elements (systems, drivers and forms of transaction) and its amplitude are exposed.

Figure 1. Source: Own elaboration (2018).

Given the multiple contributions that SE offers, it is possible to see it as an alternative towards sustainability. Within this debate, there are many discussions that corroborate the prerogative that SE contributes to sustainability (Heinrichs, 2013; Rubicon, 2015; Schor, 2014). For example, according to Carfagna et al. (2014) and Daunoriene et al. (2015), SE can restore the balance between economic, social, and environmental factors. Additionally, the SE meets the so-called holy trinity (efficiency, consistency and sufficiency) and, for this reason, promotes a more sustainable society (Heinrichs, 2013).

The role of SE in urban sustainability stands out as one of the subjects of greatest demand in society (Wu & Zhi, 2016), thus there are still discussions on regulatory, technological, political and other issues that involve sustainability. According to Daunnoriene et al. (2015), SE provides greater stability of physical and biological systems and a reduction in product production. However, the authors have made the point that this SE property depends on specific conditions and may vary depending on the business model. Hence, the SE is credited with greater efficiency in the use of natural resources from the greater use of idle assets (Fremstad, 2015; World Economic Forum, 2013).

Contributions attributed to SE also arise from its role as a generator of jobs, by encouraging the use of digital platforms that generate mass business with low transaction costs and lower information asymmetries, benefiting the supply and demand sides (Fremstad, 2015; Sundararajan, 2016). In this way, SE allows for an increase in the number of economically active agents acting to reduce marginal costs (Rifkin, 2016; World Economic Forum, 2013). Furthermore, the SE allows for a reduction in the production of goods and, consequently, generates a reduction in the consumption of energy and natural resources. Based on these reductions, SE also contributes to the reduction of waste in the environment (Fremstad, 2015).

In this context, studies show that good management of shared goods reduces the production of household waste by about 20%, and household expenses by 7% (Demailly & Novel, 2014). SE is also credited with sustainability benefits in initiatives that encourage the use of shared cars and bikes. Such benefits are seen, for example, in the reduction of carbon emissions - CO2, decrease in the demand for parking lots, reduction in the number of kilometers travelled by vehicles and reduction in the acquisition of vehicles (Luna, Uriona-Maldonado, Silva & Vaz, 2020; Nijland & Meerkerk, 2017; Schor, 2014).

Despite these arguments, many numbers about SE are questioned, and the occurrence of side effects is increasingly present in the debates (Heinrichs, 2013; Schor, 2014). Dysfunctions arise in the social, economic, and environmental dimensions, mainly due to the absence of studies that prove the benefits to sustainability (Frenken, 2017). Social problems arise with prejudices and unequal treatment involving racial issues and economic standards (Rubicon, 2015), and the exploitation of work (Schor, 2014). In the environmental dimension, there is a concern regarding the encouragement of hyper consumption (Demailly & Novel, 2014; Frenken, 2017; Schor, 2014) or even the simple expansion of consumption without complying with good practices, by involving what Prahalad and Hart (2000) call the base of the pyramid.

Based on so many scenarios, the benefit or impact caused by SE to the environment will depend, among other factors, on the regulation and institutionalized socio-technical structure. We understand, therefore, how important it is to analyze the structures in designing the models foreseen to explore sharing. Thus, businesses within SE can be explored on different platforms, such as capitalist, redistributive, or cooperative platforms (Frenken, 2017). Heinrichs (2013) notes that, to connect SE and sustainability, it is possible to establish key points, such as (1) the influence of changing consumption habits and practices on environmental and sustainable awareness and (2) the debate on economic growth and new indicators about the quality of life and wealth associated with SE practices.

Thus, the SE is seen amid the debate on business structures that integrate different economic agents and are in conformity with the principles of sustainability. Structures in SE must consider technological, behavioral and institutional factors, in both production and consumption sides. We believe that SE generates “digital partner” experiences, deals with ongoing technological processes and with the ability to integrate different digital technologies and new structures in different business models and social organizations (Martin, 2016, p. 159). Furthermore, SE can be seen as a contributory instrument, given its ability to operate in different business models, leading the integration of multiple ST-actors in public and private initiatives.

The adherence to the concepts of sharing has brought about social changes and caused positive impacts in several sectors. Therefore, SE has been used as a basis for urban reconfigurations, for example, in the scope of mobility. The mobility sector has emerged as one of the most evolved in recent years (“Economia compartilhada transforma a mobilidade humana,” 2018). The shared mobility, whether motor vehicle, bike or other modes, has provided short-term access to modes of transport, linked to the needs of each user (Shaheen & Chan, 2016). That is, “on-demand” access to shared mobility adds greater flexibility to travelers and presents itself as a more sustainable alternative (Shaheen & Chan, 2016).

Concerning the mobility discussion, there are gaps and opportunities to be explored, based on the understanding and adequacy of urban transport structures in order to better adapt to the profile of users not yet adhering to SE. Regarding the electric vehicles, their diffusion is still slow, and the general public sees them in a skeptical light. However, studies suggest that people are familiar with this option in the context of urban sharing, that is, using it in a similar way to conventional vehicles. Therefore, the SE supports the adoption of electric mobility, promoting more sustainable transport (Willing, Brandt, & Neumann, 2016).

Two initiatives were studied (Bicicletar and VAMO) integrated into a nested case study. Both initiatives are related to the Fortaleza 2040 sustainable city project existent. The Bicicletar refers to “a public bicycle system, which aims to offer the city of Fortaleza a sustainable and non-polluting transport option” (Prefeitura de Fortaleza, 2018). The system is an initiative of the City Hall of Fortaleza, operated by Serttel, and which works with the support of the sponsor Unimed Fortaleza, a cooperative of doctors. According to the city hall representative, Bicicletar is defined as “a public system, with a private operator, a private sponsor, encouraging the use of the bicycle (...)” (ENTPREF2).

The Bicicletar System is composed of “smart stations connected to an operations center via wireless” (Prefeitura de Fortaleza, 2018). The stations are powered by renewable energy because according to the initiative’s representative “the energy base is solar, we have one or another connection to the electricity base coming from the Enel network, but as an backup, if [the] solar energy is not enough to use to make the system work.” (ENTPREF2). In addition, the stations are strategically distributed in different parts of the city (Prefeitura de Fortaleza, 2018), to facilitate the access by the largest number of people.

This initiative arises with the political support, the growth of cyclo-activism in the city and the creation of the legal instrument called “Plano Diretor Cicloviário Integrado” (PDCI), in 2014. The approval of the PDCI, through the law No. 10,303 of December 23, 2014, created the Cycle Management of Fortaleza, composed by a multidisciplinary team including architects and engineers, with a focus on the implementation of the cycle plan with a horizon of action until 2030. The Bike is legitimized through a public call and opens on the 15th December 2014, initially with 15 stations, but it is expanded to 40 stations on May 15, 2015. In September 2018, the system included 80 stations (Soares, 2018).

In regard to the electric carsharing, VAMO Fortaleza (“Veículos Alternativos para Mobilidade” - Alternative Mobility Vehicles, in English), it is “an initiative to promote sustainable urban mobility through a network of shared electric cars, available in the city of Fortaleza” (Prefeitura de Fortaleza, 2017). According to city hall reports, the initiative comes as a response to the excessive use of private cars in Fortaleza, which increased problems such as noise and environmental pollution, added to the opportunities for the development of urban infrastructure. Since there is a macro project to move the city to a sustainable one, it was necessary to rethink a set of actions, which included mobility.

In this context, the City Hall of Fortaleza started a process of breaking paradigms in the municipality by adopting actions aligned with the National Urban Mobility Policy (Law No. 12,587/2012), for example, with the launch, in 2014, of the Immediate Action Plan in Transport and Transit (PAITT), made available during the interview. Thus, inserted in this set of public actions of sustainable urban mobility and the concept of sharing, in September 2016, the first public system of electric carsharing in Brazil, VAMO Fortaleza, was inaugurated, originally composed by 20 vehicles that are 100% electric, allocated to 12 stations installed in strategic public places. As the City Hall representative mentions, VAMO “(...) came to break the paradigm of use, it is not even the misuse, but the exacerbated use of private transport, right” (ENTPREF1). Ratifying the understanding of broad change in the mobility system.

The use of electric carsharing by users occurs through applications installed on mobile devices (cell phones, tablets, etc.) or through the single ticket. Amidst the characteristics of the initiatives, the premises of the SE already described in the theoretical framework are soon identified, making it possible to characterize the initiatives as systems of products and services, with technological, social, environmental and economic drivers, which enable transactions closer to the P2B2P concept, with a model without changing ownership. This discussion brings up the need to understand those involved and the process of structuring these initiatives.

Based on this discussion, it is understood that there is a debate about sharing in the integration of ST-actors. As can be seen in the speech by the city hall representative below, the models begin to stand out for this reason: “The Bicicletar, (...), it showed me what in fact, how does sharing really work here in Fortaleza. The same basic principles adopted by Bicicletar were adopted for VAMO.” (ENTPREF1). Therefore, two integrated initiatives are verified and fully aligned with the concept of sharing, introduced in the current transport system and that contribute to sustainable mobility in the urban space.

We identified the first protagonist ST-actors through initials research about the case, developed by reading the websites of the two initiatives (VAMO and Bicicletar) and reports relevant to the city’s shared mobility. Then, throughout the documentary study and interviews with the first two ST-actors (Fortaleza City Hall and Serttel), it was possible to define the other actors. This procedure considered the indication and agreement of the respondents themselves, through the crossing and legitimation of the indications (Chart 2).

Chart 2.

Record	Role	Actor-ST	Source
“(...) Special that I said before that the city can integrate us with the various areas of the City Hall, when we, when we need it.” (ENTSERT1)	Integrator	Fortaleza City hall	Serttel
“Aneel makes public calls for research projects in the area, in this case, it was electric vehicles, electric mobility vehicles. She wants to foster that, studies in this line.” (ENTUNIF1)	Developer	Aneel	University of Fortaleza
“In so, my role is exactly is ahead of this project here at City Hall always dealing with the actors involved, project, Serttel which is Operator (...) “ (ENTPREF1)	Operator	Serttelt	Fortaleza City Hall
“(...) the Hapvida group that is the sponsor of the project.” (ENTPREF1)	Sponsor	Hapvida	Fortaleza City Hall
“There’s an operator, who is Serttel, and has a sponsor that is Unimed.” (ENTPREF2)	Sponsor	Unimed	Fortaleza City Hall
“So, we have contracts today with Unifor (...) for the development of research and development projects in the scope of each object, of each project.” (ENTENEL1)	Researcher	University of Fortaleza	Enel
“For VAMO Fortaleza, we had a lot of contact [with Enel], because they made the electrical infrastructure possible, at many points that didn’t have enough power to load the cars, which has this biphase, three-phase structure.” (ENTSERT1)	Supporter	Enel	Serttelt
“We have an Association of Urban Cyclists of Fortaleza that is “Ciclovida”, an informal association created by civil society.” (ENTPREF2)	User (NGO)	Ciclovida	Fortaleza City Hall

Source: Research Data (2018).

In this sample, we can see quotations identifying the main roles of the actors, a process carried out with all ST-actors, that is, during the analyzes, the records of the different actors were combined to identify the roles of each in the implementation of the initiatives. It is noted, during the analysis, the presence of multiple records, excerpts from the transcribed speeches, from different origins, identified through the codenames already mentioned. During the analysis, we focused on identifying legitimacy from different ST-actors within the results from the composition of a premise in which, for each agent identified in the structure, there are at least two indications from different sources for validation. In other words, each ST-actor is recognized by himself and at least one second ST-actor.

With this analysis, it was possible to identify the role of protagonist ST-actors in the structure of mobility initiatives. Eight key ST-actors were mapped, mainly considering their actions in the analyzed initiatives. ST-actors with peripheral performance do not participate in this group, to the point of being disregarded without prejudice to the study. Thus, for this study, the network of interactions that promotes the structuring of shared urban mobility in Fortaleza is composed of: Fortaleza City Hall, Serttel, Hapvida, Unimed - private cooperative, University of Fortaleza (Unifor) - teaching and research institution, Enel - concessionaire of electricity, Ciclovida - NGO representing users and Aneel - National Electric Energy Agency. Such ST-actors interact through public-private partnerships in the quest to institutionalize shared and sustainable urban mobility in the city (Figure 2).

Figure 2. Source: Research Data (2018).

Figure 2 illustrates the integration structure of the ST-actors, in which a grouping was carried out, distinguishing them in the categories Government, Private Initiative, and Civil Society (Wittmayer, Avelino, van Steenbergen, & Loorbach, 2017). This grouping is seen as a way to better visualize the presence of its own triangulation and pertinent to a model of the public-private structure. As noted in the operator’s speech, “it is very clear that we operate and do maintenance, we have our contractual duties, and on the city side, they have this management and control role, to supervise.” (ENTSERT1). With this notion, it is understood that the PPP dynamics needs to clearly define what the roles of each ST-actor are.

In both Bicicletar and VAMO initiatives, the clear definition of roles occurs through specific contracts, including by users when accepting the terms and conditions, as well as the privacy policy. The definition of rights and duties corroborates with the stabilization of the system, generating greater transparency. In fact, the City mentions that “(...) we have individual contracts for each system, (...) Bicicletar also, (...) and VAMO also has another contract. So, each one has his contract, but the management is done within the same team, within the secretariat” (ENTPREF2).

It is valid to point out two issues in the performance of the public initiative. First, the government participates in two integrated and complementary instances: the municipal through the City Hall of Fortaleza and the federal, with the performance of Aneel. It is understood that “the electricity sector, to regulate funding for research and development, has a federal law, law 9,991 of 2,000, which determines a minimum investment of resources that comes in the energy bill for the development of innovation, for the development research, and development projects, and Aneel has a resolution that regulates the application of this resource.” (ENTENEL1). Second, the relevance of the roles of the public initiative stands out since, in addition to being an integrator, coordinator and regulator, the government acts as a promoter and enables the continuous evolution of the environment, since it acts not only in the structuring of systems but also in the promotion, when legislating in favor of investments in research and innovation.

Moreover, the integrated structure of multiple ST-actors based on SE occurs through direct and indirect connections. About indirect connections, for example, the City Hall does not maintain direct contact with Hapvida, an agent that acts as a sponsor. This integration takes place indirectly, through Serttel, an agent in the role of the operator who, in turn, maintains direct contacts and contracts with the City Hall and Hapvida. As indicated during the interview, “the city coordinates on her side and looks, checks the contracts and gives very strong support to Serttel. But, for example, who has the greatest contact with the sponsor is Serttel” (ENTSERT1).

This condition is also visible in the relationship between Aneel (developer and regulator) and Unifor (researcher), whose connection between the two is intermediated by Enel, which acts mainly as a supporting agent. As noted during the interview with Enel, “today, we have contracts with Unifor and Serttel for the development of research and development projects within the scope of each object, of each project: Serttel with software, and Unifor with studies and development of market research.” (ENTENEL1). This perspective highlights the existence of a clear definition of actions and roles that need to be developed for the success of the initiatives.

Therefore, amidst the composition of the structure of urban mobility in Fortaleza, the economic actors of public or private initiatives are identified, as well as the roles that each one plays. Due to the integrated visualization of these ST-actors, there is a broad understanding of the structure for the implementation of shared mobility, making it possible to view, even, different instances of action and varied types of connections between those involved. This fact is evident in the following excerpt: “When we submit to Enel, [and] when we submit to the City Hall, the results of the project stages, there is always a bias, a political, non-political view of normal politics, but political in the sense of polis, and of social benefit. A political view, of public policy that has to be considered.” (ENTUNIF1).

There is the institutionalization of some practices whose purpose is focused on the integration of a new model of urban mobility, amid a pre-existing structure, in the light of the CE. It is worth mentioning, for example, the composition of an implementation plan with a focus on coexistence and not a competition, the daily alignment of the interests of ST-actors and the gradual understanding and adequacy of projects, based on the profile of use of citizens. The proposed structure envisions an evolutionary reconfiguration movement, which seeks to insert an innovation integrated into the current system. As indicated by the city, “so that we can also guarantee integration with the other systems in Fortaleza, VAMO, it has facilities related to the single ticket, as well as Bicicletar” (ENTPREF1). There are several nuances presented throughout this implementation, which demonstrates that the sharing economy is a path to sustainability (Heinrichs, 2013). Since there are many ST-actors involved in this process, it is understood that this process has much more complexity than initially expected.