NEW BOOKS
Mayya Shmidt
People Who Care, Share
Book Review: Widlok T. (2017) Anthropology and the Economy of Sharing, Abingdon, Oxon; New York: Routledge. 218 p.
Abstract
Thomas Widlok is Professor for African Studies and Chair for the Cultural Anthropology of Africa at the University of Cologne, Germany. In his latest book, Anthropology and the Economy of Sharing, Widlok addresses the rich pool of ethnographical material from hunter-gather societies to corporate shareholding to return sharing to anthropological analysis. The book is novel in its theoretical stance because it depicts the contemporary state of the anthropological agenda compared to mainstream economic anthropology.
Widlok departs from the assumption that sharing is muchmore than a gift exchange theory and thus aims to theorize sharing in a unique manner. Thus, sharing is theorized as taking advantage of what is valued and taking opportunities for letting go. The major insights of the book are based on theoretical premises of the gift exchange theory. By rephrasing the well-known Mauss schema, Widlok suggests that "sharing creates and maintains social bonds through the opportunity to request, the opportunity to respond and the opportunity to renounce" (p. 79).
Keywords: sharing; gift exchange theory; sharing economy; theorizing; anthropology; Mauss.
The author begins the volume with a significant question: namely, how did we get the book? It is expected that it was purchased from a bookshop, but it seems that a number of readers have not done so—the book could have been downloaded or given as a gift, it could have been lent to or borrowed from someone or it could have been exchanged.
SHMIDT, Mayya — MA
Student, Faculty of Social Sciences; Research Assistant in Laboratory for Studies in Economic Sociology. Address: 20 Myasnitskaya str., 101000, Moscow, Russian Federation.
Email: mshmidt@hse.ru
The point is this: there are multiple alternatives to market modes of transfer. Anthropological thought, however, often reduces all non-market modes of resource allocation to gift exchange and reciprocity. Thomas Widlok seeks to use anthropological knowledge to develop a theory of the social practices of sharing. The point of departure here is the idea that sharing is far away from the theory of gift exchange, which is crucial for anthropology. Sharing, as Widlok puts it, is a distinct category that demands its own theory for interpretation. Thus, the aim of the book is to assemble the most appropriate understanding of what sharing is about.
Anthropology and the Economy of Sharing proceeds via the following structure: The Introduction familiarizes readers with the notion of sharing, which is "the social practice of enabling access to what is valued on the basis of shared demands" (p. xvii). Consequently, Widlok sets the main prerequisite for counting some social practices as sharing, and that is sharing one another's demands.
The author then proceeds with seven chapters, each highlighting a different aspect of the notion of sharing. Chapter 1 aims to theoretically distinguish a sharing perspective from the paradigms of gift exchange and reciprocity. Chapter 2 attempts to find a place of sharing in debates between evolutionary and cultural-historical thought. "Evolutionary models link sharing with questions of original altruism and generosity which is ethnographically unwarranted' (p. xvii). As Widlok puts it, various empirical ethnographic evidence shows insufficiency of the models when it comes to general explanation, and so the focus switches toward a need to examine the social practice of sharing.
Chapter 3 reveals emerging patterns of sharing. Here, Widlok suggests that Mauss's threefold system of obligations considering gifts (namely, obligations to give, to receive and to return) provides the same patterns suggested by the ethnography of sharing, which are opportunities to ask, to respond and to renounce. Chapter 4 examines the things we share and presents sharing as a distributive process.
Chapters 5 and 6 discuss evidence from modern globalized society, in which corporate agents and shareholders challenge property relations and initiatives labeled "the sharing economy" strive to solve the challenges of a capitalist economy. The last chapter examines polar cases of small-scale and large-scale societies with regard to timing issues (when is the right time to share?) and the problem of over sharing.
Throughout the book, Widlok emphasizes that sharing practices are embedded in historical and cultural settings. Therefore, special attention must be paid to the ethnographic case study boxes included in the book.
Although the author provides ethnological evidence from hunter-gather societies to corporate shareholding, readers should not consider the book as one that describes the evolution of sharing. Rather, Anthropology and the Economy of Sharing should be viewed as the first profound work that theorizes sharing as a self-standing paradigm.
"The Myth of Reciprocity".1 Why do We Need a Self-Standing Paradigm of Sharing?
Anthropology emphasizes gift-giving, and this agenda, as Widlok shows, is extremely fruitful for "developing alternative ways of enabling access to services and goods" (p. 14). However, since sharing phenomena are often acknowledged as cases of gift exchange or reciprocity, the proper conceptualization of the former is crucial. For example, the theoretical apparatus of gift exchange fails to explain the contemporary phenomena of resource allocation—namely, the so-called sharing economy, which is the non-commercial organization of exchange, brought into existence by digital platforms, where users who are strangers to one another organize peer-to-peer networks and thus create a community in which no one knows each other by name, but all have the right to invest their resources and use the resources of others. Further, we expand on the controversy of this modern mode of organizing economy beyond market. Practices of labeling modes of allocation of resources can be sophisticated. As Widlok (p. 68) puts it, "calling something 'sharing', or refusing to use that term and using a different one instead, is in itself part of the phenomenon under study."
By arguing that sharing is distinct from both gift-giving and reciprocity, we will turn to the historiography of the subject. B. Malinowski's and M. Mauss's anthropological studies show the existence of institutes that regulate procedures of gift-giving and provide a mechanism that obliges us both to receive gifts and to reimburse them. In the kula, the circle of ceremonial exchange described by Malinowski, the imperative of gift and counter-gift is working. On the one hand, each participant in a gift exchange cannot interact with others if he does not bring something as a gift. On the other hand, the counter gift must be comparable to the initial gift. The only rule is that one cannot reciprocate with an equivalent of the initial gift, since it should not demonstrate a "price" for the gift received. Malinowski [2002] emphasizes that the logic of gift-giving is fundamen-
1 [Pryor, Graburn 1980].
tally different from the utilitarian economic logic as far as the underlying motivation of the kula is to bring a ceremonial gift that will be reimbursed by an equal counter-gift, but literal exchange is never made from hand to hand so that the equivalence of objects is discussed. Malinowski assumes that exchangeable items can serve as an alternative to money or can be treasures.
However, anthropologists' initial assumptions have been refused as far as exchanged bracelets and necklaces served neither as a form of money (since they could not be exchanged for items other than necklaces and bracelets) nor as a treasure, since no tendency to preserve or multiply these objects was observed. Quite the contrary, a desire to get rid of objects or to pass them forth took place, as exchanged items have a certain symbolic load that cannot be subordinated to the logic of economic exchange. With regard to the time-lapse of gift exchange, the one and only ceremonial moment in which transaction occurs can be conceived, while sharing lacks such temporality: "it lacks a need for temporal and special centre.. .the decentralization and disconnectedness are properties that facilitate sharing and are part of its own logic" (p. 61).
The orderly kula gift exchange circle, the functioning of which was described by Malinowski, is similar to the potlatch practice in the anthropology of Mauss [2000]. As a total institution, potlatch ensures the functioning of a threefold informal obligation to give, to receive and to return. Thus, in the anthropology of Mauss, the gift is not only a "social and economic necessity stemming from the functional requirements of the modern economy, but an element of economic art, ultimately necessary for the gift giver himself' [Gofman 2011: 39]. The "obligational" part of the exchange, however, is irrelevant in sharing, as no informal "indebtedness" occurs when there is no transfer of ownership in peer-to-peer exchange [Huurne et al. 2017].
"Because exchange objects have symbolic dimension, gift transactions can be understood as expressive statements or movements in the management of meaning: transaction becomes the basic expressive act by which symbols mediate cultural meanings. Gift-giving, then, is properly a vehicle of social obligation and political maneuver" [Sherry 1983: 157]. Widlok argues that the social practices of sharing are followed with neither demonstration of generosity nor displays of power, which make them distinct from gift-exchange.
Polanyi [1957 (1968)] proposed avision of economy as an instituted process by outlining three types of economic organization—namely, reciprocity, redistribution and market exchange—that require a certain institutional mechanism for implementation. Reciprocity refers to the exchange of goods between symmetrical social entities. Following a substantivist approach, Sahlins [1972] introduced the system of reciprocities: generalized reciprocity (altruistic transactions), balanced reciprocity (a direct exchange of equivalent goods between two parties) and negative reciprocity (impersonal utilitarian exchange similar to barter swapping). Generalized reciprocity is the closest to sharing because it supposes asymmetrical relations between parties.
According to Steiner [2015], in a market-driven society, reciprocity takes much more complicated forms than those introduced by Polanyi, and organizations make some of these forms possible. This is a very important notion as long as reciprocal transfer exchange and gift-giving conventionally fall into the sphere of "household economy," while sharing can be considered at multiple levels of social organization, from local community arrangements to market-mediated practices.
Anthropologists argue that "sharing" refers to the "allocation of economic good sand services without calculating returns, within a <...> social group, and patterned by the general role structure of that group" [Price 1975: 4] or "allowing others to take what is valued" [Widlok 2013], which suggests an underlying idea of community. Sharing means both sharing out (dividing something between individuals) and sharing in (joining individuals in a common-use action) [Bird-David 2005: 203], and there is an analytical need to distinguish these notions. While sharing in has a more pragmatic nature, sharing out practices suggest extending the circle of individuals benefiting from a shared resource [Widlok 2004]. Restriction to small-scale social groups, such
as kinship-based groups, is not the case for sharing, which is mediated by the Internet, which unites millions of anonymous users in contemporary economies. The Internet either brought new alternatives, such as file sharing [Belk 2014],or gave new dimensions to old form.
Widlok prefers to speak of mutual recognition rather than "reciprocity," which is overused in the social sciences (p. 28). The notion of reciprocity defines sharing practices in numerous studies and by mapping previous research. Widlok claims that ethnographers conducting fieldwork in different parts of the world insist on sharing as the subject matter of their observations.
Pryor and Graburn's [1980] study of Inuit sharing in northern Canada sheds light on the reciprocal effect of sharing. Empirical quantitative research relied on data gathered from 300 visits to households in a community inhabited by 254 people, through which 1,250 facts of "distributional transactions" were recorded. A community network was strictly composed of net receivers and net providers that did not intersect by any criterion (gender, marriage status, income, disability). Thus, any transaction could not be evened out reciprocally, and all transactions were characterized by imbalancedness (pp. 13-15).
Widlok therefore devises a set of indicators that differentiate sharing from other modes of exchange: "the list for sharing would include characteristics such as non-reciprocity, creating links to others, inclusion, caring, which are often (but not always) associated with sharing and there are 'counter indicators' such as reciprocal expectations, two-way exchanges, debts etc. which we find among gift giving and commodity exchange" (p. 21). Given Widlok's line of reasoning and summarizing evidence from the mentioned studies, we provide the following table 1, which summarizes the main differences in more detail and shows sharing as a self-standing mode.
Table 1
Modes of Exchange
Gift exchange Market Reciprocity Sharing
Exchanging Purchasing Giving to one another Dividing
Collectivism Anonymity Non-anonymity Personal autonomy
Exchange creates Competitive behavior Communication on Extending the circle of people
commitments the basis of non-economic preferences who can enjoy the benefits of the shared resource (p. 24)
Direct back-and- Strict equivalence of Mutuality of Mutuality is lost as the definig
forth coupling transfers, monetary nature transfers property
Gifts followed by Regular exchange Expectations of Often has no recognizable return
counter-gifts reciprocation
Two-way transfers Two-way transfers Two-way transfers Unilateral transactions
Kin obligations Anonymity Symmetrical groups Transfer is not based on specific kin obligations, do not create long-term commitments
Balance Strict equivalence Balance Imbalancedness of transfers
Replacing Obligations with Opportunities
In the previous section, we outlined the reasoning for considering sharing a distinct paradigm in economic anthropology and expanded on why the gift-giving theory has limitations to explain the social practices of sharing. The following paragraph is devoted to Widlok's practice-oriented approach, which takes into account social factors that enable sharing.
By rephrasing the well-known Mauss schema, Widlok suggests that "sharing creates and maintains social bonds through the opportunity to request, the opportunity to respond and the opportunity to renounce" (p. 79). Here, opportunity instead of obligation means that in sharing there is no external obliging force such as the hau spirit described by Mauss. Opportunity can either be taken or denied. By replacing "the obligation to give" with the "opportunity to request," Widlok switches the focus to potential rather than to forced exchange partner. Both material and immaterial objects are not readily offered; there is a need to make a request. The idea of "social contact," as Widlok puts it, underlies replacement of "the obligation to receive" with "the opportunity to respond." It implies expectations of being oriented toward others, of making a proper request and a proper response to it, and thus affects future contacts and future responses to demands. Finally, "the obligation to return a gift" is replaced with "the opportunity to renounce or to let go," which means that human beings are not infinite and that things we gain cannot always stay with us. Moreover, each deals with constant unevenness and limitations, and there is no chance to overcome this asymmetry (pp. 80-81).
Demanding on Sharing
Here and elsewhere, Widlok defines sharing ethnographically as "enabling access to what is valued through a bundle of social practices of responding to demands" (p. 78). By "demands," the author means direct vocal statements. Thus, initiated by a demand, sharing starts with the action of a needy recipient rather than that of a giver: "responsiveness to the perceived needs of others is a defining and constituent feature of sharing" (p. 84).
"Cultural work," as Widlok advocates, is crucial for recognizing demands and selecting appropriate responses to them. What can make a demand a successor a failure? In the case of sharing, failure is not applicable to "repayment." As Graeber [2011] puts it, debt has been the pattern for the last five millennia. Both commercial transactions and gifts that are not repaid or returned fail. Unsuccessful sharing, though, is a matter of the inappropriate statement of demand or the potential provider's inability to share. Further, a key to successful sharing is in making acceptable demands and giving up demands: "sharing cultivates preparedness to give up things on an everyday basis with regard to objects of personal property but also with regard to being in a privileged asymmetrical position towards others" (p. 85).
Sharing implies granting access to both material and immaterial objects. Thus, multifunctional assistance takes place in communal agreements, examples of which can be found in many studies of gift economy. The lack of resources in times of scarcity is confronted by addressing path-dependent practices of providing mutual aid. A typical example of such practices that may be familiar to the reader is the so-called blat in Russia [Ledeneva 1998]. Following Ledeneva's research inquiry, "economies of favour" (blat) chronicle pervasive Soviet citizens' practices of using personal ties to access scarce resources and thus leads reasoning to "more a system of sociality and a moral aesthetic of action" [Henig, Makovicky 2017: 4].
Widlok suggests extending the notion of demand sharing to "demand cooperation", and in this context, examples of gift economy seem to be a fruitful tool for analyzing sharing in terms of "communities of practice" (p. 93). The notion could be interpreted twofold: on the one side, it refers to a community as a group of those who demand and respond; on the other, it considers settings of gaining knowledge of what is appropriate to do in particular situations in the group and constant "situated learning".
Widlok addresses shareholding to highlight the switch in attention from kinship to large-scale groups. Shareholders are "incorporated agents whose well-defined circle of members have fixed entitlements to a share of whatever it is that the corporation owns, holds or claims" (p. 133).
Regarding the example of the shareholding structure of Thyssen Krupp, a German multinational conglomerate, Widlok expands on what is it to be a shareholder in a world where corporations define and shape the or-
ganization of sharing. First, it is characterized by the size of the groups—commercial corporations are divided by millions of shares—and the nature of sharing changes within this condition. Huge size is connected with anonymity, as shares are purchased freely, and individual owners do not strive to establish relations with others. Moreover, there is no ideology of generosity or affection toward the company of underlying sharing, and thus, profit-making becomes the aim for sharing.
The focus is switched to establishing legitimate membership status, or group recognition, which is strictly impersonal and institutionalized. The means of obtaining a share are proof of permanent residency and sufficient funds in a valid bank account. This feature depicts a move from personal to non-personal modes of sharing (pp. 128-130).
There are more cases connecting sharing and challenges of resource allocation in modern manifestations of sharing. The most controversial is the so-called sharing economy.
Contemporary State of Sharing: The Sharing Economy and Its Paradoxes
Over the past decade, we have observed anenormous rise of alternative forms of organizing the economy, such as the sharing economy, collaborative consumption, the crowd funding form of investments, etc. Time included the sharing economy in the list of "10 Ideas That Will Change the World" [Walsh 2011]. Terrains of the sharing economy that are widely discussed include peer-to-peer accommodation (Airbnb, Couchsurfing), transportation (BlaBlaCar, Uber, Lyft, Zipcar), on-demand household (DIY services, delivery networks like UberRUSH) and professional (freelancer platforms) services and collaborative finance (crowdfunding and lending platforms) [Vaughan, Daverio 2016]. Origins of sharing economy activities can be traced to the founding of eBay and Craigslist as marketplaces where buyers and sellers meet to recirculate goods, and platforms amounted to some thousands by 2010, providing goods and services from clothes-swapping to peer-to-peer bank services such as loans, debts, investments and insurances. What unites them is the creation of an ideological movement that confronts overproduction and overconsumption crises by addressing sustainability motivation: shared ownership, reuse and recycling, collaborative consumption and joint purchases. While some argue that the sharing economy addresses anti-capitalist rhetoric and strives to invent a novel means of resource allocation, others assume that the sharing economy is not about sharing at all [Eckhardt, Bardhi 2015]: "that label [sharing economy] is either strategically or unwittingly employed to expand the market rather than sharing in the sense of providing access to goods" (p. 193). Thus, the sharing economy is quite contradictory in its fundamental reasoning.
As Widlok [2017] puts it, if practices are indeed a commodification of resources that were formerly excluded from market logic, why do they become framed by a rhetoric of sharing?
Consistently bringing insights from initiatives thatare more commonly considered sharing economy, Widlok concludes that "much of what goes under the notion of 'sharing economy' is in fact an extension of the market economy into spheres of life that were previously exempted from the market" (p. 161).
Car-sharing is the pioneer of the sharing economy movement, where the logic is to "use" but not "own." Still, the use-rights are purchased by registered customers from a car-rental company that owns the pool of vehicles and decides the fees for exchange. The same is true of taxi apps like Uber or Lyft, which connect drivers using their own cars and lifting passengers for a "tip." App businesses occupy a niche in the taxi market—so-called "distributors of the app" do not own taxis, but their profit is more valuable: not only do they get interest, but they aggregate huge amounts of data that are vital to predicting patterns of customer behavior.
Old-school hitchhiking or joint rides to a workplace among colleagues are much closer to what Widlok means by sharing, insofar as in these demands are made by those who need a lift, followed by the driver's response: granting access to a place in a car (pp. 140-141).
Another widely discussed evidence is LETS (Local exchange and trading systems), which collectively shares a pool of goods and services and introduces its own parallel currency for exchanges. Local systems are attractive to materially insecure people, whose needs are not satisfied by the market, and to local businesses that want to escape collection of VAT and other taxes. Widlok argues that the LETS scheme is one of a barter nature. Sharing is decentralized and lacks an institutionalized and powerful distributional center. Moreover, the collective consciousness of common pooling is far away from sharing, which cultivates individual autonomy and the leveling of power (p. 146).
* * *
It does not go unnoticed that the rise of scholarly interest in alternative forms of economic exchange in the EU and the USA began in 2008 as the economic crisis started to intensify. Numerous studies are dedicated to a wide spectrum of subject matters, from limits of markets to rejection of the institutional setting of capitalism. Scholars began to rethink market capitalism by addressing alternative forms of organizing the economy, such as the sharing economy, presented as a breakthrough in the previous dynamics of a capitalist economy since it deals with accessing products and services over exclusive private property and ownership and emphasizes cooperative, rather than competitive, market behavior. For sharing economy domains, this means that an appreciation and valuation of «community» emerge from meeting with neighbors or making joint purchases. Still, critique, brought by Widlok to the label of «sharing economy», makes us remember that this speculative notion is far removed from actual sharing in a broad sense. Sharing is unnoticed and unappreciated as a vital humanistic and moral value, and thus it becomes a room for maneuvering both academic audiences (who confuse sharing with reciprocity, gift-giving, barter swapping and favors) and practitioners (who promote market-mediated practices through the lens of social rules such as reciprocity).
In complex economies, sharing practices carry a rhetoric of expectation of improving economic inequality, as though sharing can replace economic exchanges. "When sharing complements market transactions that continue alongside and when it is embedded and framed by market conditions, it often requires some careful unpacking as to which practice has what kind of effects" (p. 158).
By comparing evidence from different social and political settings, from hunter-gather societies to the world of shareholders, Thomas Widlok devises a fit theory of sharing as a self-standing approach in anthropology, distinct from the authoritative gift exchange paradigm. Since there is little comparable existing literature, the book is novel in this perspective. The author himself describes the book as "helping students to avoid Western economic bias in their thinking." Anthropology and the Economy of Sharing is a profound study, precisely argued and clearly illustrated with thousands of ethnographic records that could equally be found on a student's bookshelf among other course literature and on the shelves of social scientists studying sharing from an anthropological perspective.
References
Belk R. (2014) You are What You Can Access: Sharing and Collaborative Consumption Online. Journal of Business Research, vol. 67, no 8, pp. 1596-1600.
Bird-David N. (2005) The Property of Sharing: Western Analytical Notions, Nayaka Contexts. Property and Equality. Volume 1: Ritualisation, Sharing, Egalitarianism (eds. T. Widlok, W. G. Tadesse), New York: Berghahn, pp. 201-216.
Eckhardt G. M., Bardhi F. (2015, January 28) The Sharing Economy Isn't About Sharing at All. Available at: https://hbr.org/2015/01/the-sharing-economy-isnt-about-sharingat-all (accessed 17 November 2017).
Gofman A. B. (2011) Sotsial'naya antropologiya Marselya Mossa [Social Anthropology of Marcel Mauss]. Mauss M. Obshchestva. Obmen. Lichnost': Trudypo sotsial'noy antropologii [Society. Exchange. Personality. Works on Social Anthropology], Moscow: KDU, pp. 7-54 (in Russian).
Graeber D. (2011) Debt: The First 5,000 Years, New York: Melville House.
Henig D., Makovicky N. (eds) (2017) Economies of Favour after Socialism, Oxford: Oxford University Press.
Huurne M. ter, Amber Ronteltap A., Corten R., Buskens V. (2017) Antecedents of Trust in the Sharing Economy: A Systematic Review. Journal of Consumer Behaviour, vol. 16, no 6, pp. 485-498.
Ledeneva A. V. (1998) Russia's Economy of Favours: Blat, Networking and Informal Exchange, Cambridge: Cambridge University Press.
Malinowski B. (2002) Argonauts of the Western Pacific: An Account of Native Enterprise and Adventure in the Archipelagoes of Melanesian New Guinea, London: Routledge.
Mauss M. (2000) The Gift: The Form and Reason for Exchange in Archaic Societies, New York: WW Norton & Comp.
Polanyi K. (1957 [1968]) The Economy as Instituted Process. Primitive, Archaic andModern Economies. Essays of Karl Polanyi (ed. G. Dalton), New York: Anchor Books, pp. 139-174.
Price J. A. (1975) Sharing: The Integration of Intimate Economies. Anthropologica, vol. 17, no 1, pp. 3-27.
Pryor F., Graburn N. (1980) The Myth of Reciprocity. Social Exchange. Advances in Theory and Research (eds. K. J. Gergen, M. S. Greenberg, R. H. Willis), New York: Plenum Press, pp. 215-237.
Sahlins M. (1972) Stone Age Economy, Chicago; New York: Aldine-Atherton.
Sherry J. (1983) Gift Giving in Anthropological Perspective. The Journal of Consumer Research, vol. 10, no 2, pp. 157-168.
Steiner P. (2015) The Organizational Gift and Sociological Approaches to Exchange. Re-imagining Economic Sociology (eds. P. Aspers, N. Dodd), Oxford, UK: Oxford University Press, pp. 275-298.
Vaughan R., Daverio R. (2016) Assessing the Size and Presence of the Collaborative Economy in Europe. Available at: http://ec.europa.eu/DocsRoom/documents/16952/attachments/1/translations/en/renditions/ native (accessed 17 November 2017).
Walsh B. (2011) 10 Ideas That Will Change the World. Time. Available at: http://content.time.com/time/spe-cials/packages/article/0,28804,2059521_2059717,00.html (accessed 17 November 2017).
Widlok T. (2004) Sharing by Default: Outline of an Anthropology of Virtue. Anthropological Theory, vol. 4, no 1, pp. 53-70.
Widlok T. (2013) Sharing: Allowing Others to Take What is Valued. HAU: Journal of Ethnographic Theory, vol. 3, no 2, pp. 11-31.
Widlok T (2017) Anthropology and the Economy of Sharing, Abingdon, Oxon; New York: Routledge. Received: September 21, 2017
Citation: Shmidt M. (2017) People Who Care, Share. Book Review: Widlok T (2017) Anthropology and the Economy of Sharing, Abingdon, Oxon; New York: Routledge. P. 218. Journal of Economic Sociology = Eko-nomicheskaya sotsiologiya, vol. 18, no 5, pp. 159-167. doi: 10.17323/1726-3247-2017-5-159-166