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Reflections on “Brokerage and Closure”
Social Networks 29 (2007) 330–339
Book review Reflections on “Brokerage and Closure” Brokerage and Closure: An Introduction to Social Capital, R.S. Burt. Oxford University Press (2005) 1. Structural holes—an overview The publication of Ronald S. Burt’s Brokerage and Closure: An Introduction to Social Capital (Oxford University Press, 2005) is cause for celebration among network enthusiasts. In this excellent new addition to the expanding literature on social capital and organization studies, Burt provides an extensive introduction to his theory of social capital. The book is well written, comprehensive and persuasive, and it summarizes the theory of one of the most influential and cited scholars in the field. Structured around four main chapters, two dealing with brokerage as social capital and two with closure as social capital, the book is a detailed account of Burt’s research activities and theorizing to date. Readers who are familiar with Burt’s work and his teaching materials in the last 10 years will find themselves on familiar grounds. Yet, the book is the most complete presentation of his ideas regarding structural holes to date. Readers new to the idea of social capital will get an extensive, clearly written, compelling introduction, especially as it pertains to Burt’s ideas about brokerage as social capital. However, the book is not an introductory textbook. While it does not include complex methodological notes as part of the main text, appreciating the complexity of Burt’s ideas require the reader to be well versed in social sciences methodology and theory and to have some familiarity with social network analysis, especially with network indices and structures. We take the opportunity of celebrating Burt’s new book to review Burt’s academic career in terms of brokerage and closure, and to reflect on the theory of social capital as presented in the book. Therefore, this review is structured in three sections: first, we provide a brief intellectual and professional context for this book. Specifically, we argue that in concordance with the book’s main argument, Burt has reaped the benefits of brokering relationships between academic disciplines. Second, we provide a brief summary of the book. Third, we attempt to open Burt’s rigorous business-oriented sociology in ways that might enrich organizational studies specifically, and network theory generally.
0378-8733/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.socnet.2007.01.001
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2. Brokerage and closure in Burt’s publication trajectory Ronald Burt’s book continues his long-standing interest in strategies of advantage in competitive markets. Over the past three decades Burt used several studies to investigate different aspects of “brokerage-as-social capital”. He has focused, for example, on gains in competitive markets, on manager promotion rates (Burt, 1992), on personality correlates of structural holes (Burt, 1998), and on the good ideas inherent in bridging structural holes (Burt, 2004). He consistently shows that people who bridge the holes between different social worlds (groups, cliques) enjoy the advantage of having good ideas because they have a broader vision than people with constrained networks. Stemming from this vision advantage, people with access to structural holes enjoy the potential of gaining an advantage by capitalizing on their good ideas. Burt’s pragmatic interest in profitability was clearly stated in the overriding questions he posed in his earlier work: How does the structure of competitive buying and selling among organizations actually operate to constrain corporate profits? How could that competition be brought under control by the existence of non-market connections between organizations? To what extent has it been brought under control? These are my central concerns in this book (Burt, 1983, p. 2). More than 20 years later, his commitment is the same: understanding “the problems of how to create value” (2005, p. 8). We highlight two theoretical positions that we suggest are essential for Burt. The first is the idea of rational agent and the second is the idea of social structure enabling action. In his early theoretical statements, Burt aligns himself with Coleman in suggesting a general theory of action. In that context, Burt explicated his assumptions about the nature of action: My experiences with people lead me to hold two beliefs as a fruitful foundation for constructing systematic social theory. First, people as individual or group actors are purposive, in the sense of using their resources to realize their interests. Second, these purposive actors pursue their interests in the context of social structure generated by the division of labor in society (Burt, 1982, p. ix). For Burt, organizations constitute opportunity structures, and he assumes that rational actors actively seek opportunities for securing advantage by using the information that flows through their position and by controlling the action of others. We return to this point in section 4, when we propose ways in which the theory can be extended. The second theoretical tenet bears similarity with Simmel’s structural analyses of social positions as “forms” or types of social relations (e.g., the dyad and triad). Simmel suggested that people with opportunity structures of the Tertius gaudens (the position of the third party who wins) develop a “stranger” mentality: a broader vision, objectivity, coldness and manipulability (Simmel, 1950, 1990). Burt expands on this insight by arguing that social positions in heterogeneous settings provide opportunities and limitations on action by affecting two main sources of power: information and control. Those actors who find themselves in positions with non-redundant sources of information can gain an edge in competitive economic markets by making strategically smart moves in organizations. Utilizing these two tenets, and borrowing ideas from other sociologists (such as David Krackhardt and Mark Granovetter) and economists (such as Frederick Hayek and Joseph Schumpeter), Burt developed his theory of structural holes, described at length in Section 3. His main concern
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Fig. 1. Citation patterns by year and discipline.
remains how to “create value” while assuming rational agents and the social structures in which they are embedded. During the past three decades, he has written six books, about 65 journal articles and 15 book chapters, most of them focused on the interplay between social positions and advantage in organizations.1 He employs conceptual wizardry – minting or creatively using concepts such as social capital, structural holes, structural autonomy, network closure, bandwidth, echo, rigidity, equilibrium and inertia – for a better understanding of hindrances on market efficiency and of entrepreneurial opportunities in competitive organizational arenas. A bird’s eye view of Burt’s publications shows a consistent decline in their number across the first three decades of his career, compensated by a growing trend of citations. In terms of content, the trajectory of his publications suggests that after a very ripe methodological period (ending in 1983), Burt focused his energies on developing his own theoretical approach, epitomized by his 1992 book, Structural Holes. Clearly this has been the most cited of his works: as of June 2006 the book was mentioned 1598 times in Google Scholar). From 1992 onward, his publications focus on attempts at integration, synthesis and application. As of 1995, Burt often uses “social capital” to position his own take on this popular concept, predominantly vis-`a-vis the work of James Coleman who popularized the concept in sociology. A focused look at the places where Burt published his articles suggests that he has largely concentrated his publications in a single journal, Social Networks: home to 21 (32%) of all his journal articles. Other major outlets are Social Science Research (11%), and the American Journal of Sociology, Social Forces, and Sociological Methods & Research—each housing 5 (8%) of his 65 refereed papers. This concentration – and the fact that only 8 (12%) of his papers have appeared in organizational journals – show that Burt’s publication efforts have been focused on the discipline of sociology, despite his prominence among organization scientists and his position in the Chicago Graduate School of Business. In Burtian terms, he enjoys a closed sociological network, in which (as he argues in his new book), trust and reputation can emerge. However, in terms of impact, Burt has been successful at brokering his ideas to the world of organizational analysis. Citations to his articles by discipline (Fig. 1) suggest that his ideas
1
Based on information from Burt’s website: www.gsb.uchicago.edu/fac/Ronald.burt (accessed on April 2006).
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have been gaining acceptance across disciplinary borders. While his early publications were mostly cited in sociology journals (63% of the total cites for 1975–1985 were in sociological journals and 24% in business and management journals), his later publications were mostly cited in management and business journals (only 28% of the total cites for 1996–2005 were in sociological journals while 65% were in management and business journals). Ronald Burt’s attempt to broker between academic disciplines is similarly evident in his efforts to broker ties between academia and business organizations. He has provided executive education to firms like BMW, Cable & Wireless, Exxon, IBM, and L’Oreal. Most importantly, he was Director of the Raytheon Leadership Institute (2000–2003) and Vice-President of Strategic Learning at Raytheon (2001–2003). Burt is clearly a man who walks the talk and practices what he preaches. It comes as no surprise, therefore, that in his new book Burt pays much attention to the importance of brokerage as social capital. It is what he does best and what has generated his many good ideas. Yet, as we argue later, Burt’s pragmatic orientations and focus on the business world may have also produced closure in his theoretical foci. 3. The themes of the book Brokerage and Closure is rich and dense with ideas, evidence and corroborations. Four chapters form its core: two dealing with brokerage as social capital and two with closure as social capital. Each chapter begins with the description of studies conducted by Burt and colleagues, continues with extensive evidence and corroborations from other disciplines, and closes with a stylized fact: a slogan that provides a summary of the chapter. Moreover, in the course of reading the book, readers cannot avoid the impression that the book leads them through various sources of evidence that are robustly connected to each other. At times, they may feel too well connected. Below we present a brief summary of the main arguments in the book. The introduction contrasts brokerage and closure and suggests that optimizing for closure (operationalized as within-group contact volume) is inefficient. Burt asserts that informal organizations are composed of dense social clusters with occasional bridge relations connecting them. Since opinions and practices are more similar within groups than between groups, a person who brokers relations across a structural hole has the advantage of early access to knowledge and opportunities for coordinating across groups—a social capital advantage. This advantage translates into more positive evaluations, early promotion and higher compensation. Thus, “brokers do better”—Burt’s first stylized fact. According to Burt, brokerage positions have more advantages—they provide visions of options otherwise unseen. In essence, “brokerage puts people in a position to learn about things they didn’t know they didn’t know” (p. 59). Thus, Burt’s second argument (Chapter 2) is that people who occupy structural holes have better ideas. Brokerage is presented as a multi-level phenomenon through which a person could create value. Thus, value could be created through awareness of the complexities that other groups are faced with, transferring best practices to the other groups, drawing analogies between the two groups, and synthesizing ideas present in both groups. This vision advantage helps brokers to use their positions to generate new beliefs or behaviors that synthesize elements from both groups. As evidence, Burt presents data that is based on relationships between managers in a large supply chain firm discussing ideas for improvement. This idea is then strengthened by research from other disciplines, and is summed by Burt’s second stylized fact: “Improved vision is the mechanism responsible for returns to brokerage”. In the first two chapters, the reader is left with the impression that brokerage is the only mechanism associated with social capital. The next two chapters deal with the advantages of closure
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as social capital. Burt asserts that the trust needed to realize the value of bridging structural holes is ensured by network closure: “Brokerage is about coordinating people between whom it would be valuable, but risky, to trust. Closure is about making it safe to trust” (p. 97). Based on ideas by Simmel, Krackhardt, Granovetter and Coleman, Burt argues that in situations where trust is an advantage, there is social capital in closure. In fact, embedding a tie in multiple, strong third party ties (i.e., creating Simmelian ties and closure) enhances social control through reputation. The working hypothesis for this chapter is that “strong and positive third party relations between two people invoke closure’s reputation mechanism, which lowers the risk for either person trusting the other, making trust more likely” (p. 112). Since closure is “about making it safe to trust” and brokerage is “about coordinating people between whom it would be valuable, but risky, to trust”, the chapter suggests combining the two: namely, the social capital of structural holes depends on trust to deliver the value created by brokerage. Thus, the third stylized fact is that performance is a product of brokerage outside the group and closure inside the group. Having convinced us that both closure and brokerage are valuable to performance, Burt examines how trust is generated by closure, by comparing the “Bandwidth” and “Echo” hypotheses. His Bandwidth hypothesis argues: “Strong, redundant connections ensure a reliable flow of data so that everyone in the network is informed about behavior that enhances or erodes reputation” (p. 167). The hypothesis suggests that dense networks enhance flow of consistent information across the network. Third parties “had no motive” (p. 168) to disclose information. They are simply viewed as pipes through which information flows. Thus, according to Bandwidth, trust is the result of consistency of information across the network. The Echo hypothesis, on the other hand, is based on “the social psychology of selective disclosure in informal conversations”, whereby “third parties communicate a sample of what they know, a sample defined by etiquette” (p. 168). Contrary to Bandwidth, Echo provides people with a “motive”, following the rules of etiquette (see pp. 172–178). Burt argues that people are motivated by social etiquette, and as a result selectively filter and reproduce information with gossip. This reproduction of information in closed networks not only creates consistency of information across the network (i.e., Bandwidth), it also creates more intense feelings in which perceptions are constantly reinforced by networks and therefore become further removed from reality. The data presented in this chapter provide evidence that the Echo hypothesis is more accurate than the Bandwidth hypothesis. Closure is not only associated with better control (peer pressure) of behavior, but due to the Echo mechanism, closure also creates increasingly more biased perceptions of third parties. As a result, new relations between friends of friends are protected from tie decay. These relations are likely to survive to maturity, reinforcing the existing structure through increased density within clusters, which in turns leads to further echoing of perceptions. In addition, it leads to increased distance between clusters coupled with increased rigidity within clusters. The stylized fact for the fourth chapter is that gossip and reputation have a strong, possibly insidious effect in closed networks, and they create rigid, stale, and closed cliques. Questions regarding equilibrium and the costs and benefits of brokerage and closure were highly needed at this stage of the book. The fifth chapter, the most innovative of the book, is about change and inertia in network structures. Here, Burt adds time to the structural dimension in order to hypothesize about the development of network structures longitudinally. Bringing into discussion the Austrian school’s market metaphors of Schumpeter and Hayek, he argues that since information is always imperfect and incomplete, there is a premium given to people
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who are network entrepreneurs. These entrepreneurs create valuable knowledge combinations from knowledge that is otherwise segregated in separated groups. Equilibrium is reached when the benefits associated with creating new combinations (brokerage) are balanced by the price paid for integrative work. For early entrepreneurial bridging, the returns for integration are highly disproportional; while for successive bridges built across structural holes, the returns diminish. The price paid for (and benefits associated with) brokering is partially the result of another important distinction Burt draws: between active and passive structural holes. Based on Charles Tilly’s work, Burt defines a structural hole as active if interests attached to the hole resist bridges (e.g., in cases in which competing interests to bridge a hole erode each other). He sees four mechanisms that keep structural holes active: (1) if they provide opportunities of insiders to exploit outsiders; (2) if they permit insiders to hoard opportunities from outsiders; (3) if insiders can establish new organizations in which insiders are at an advantage; (4) if routines, social, information, and influence ties have adapted to the hole. Conversely, Burt defines a hole as passive if information flows freely across it, thus diminishing the value of subsequent bridges. Implied in his distinction is that slow moves to equilibrium are associated with active holes and therefore offer brokers longer advantages. Burt treats equilibrium as a local balance between closure – pulling towards conformity and rigid structure, and brokerage – pulling outside groups towards change and new ideas. Closure has internal stabilizing forces that are typically stronger compared with brokerage. Yet brokerage has the potential to bring endogenous change. The pull towards the group suggests that structural holes are perceived as empty space until entrepreneurs find value in coordinating across the holes. At that point, a new process towards equilibrium commences, with more and more people spanning the structural hole with diminishing returns until a new equilibrium is reached. To summarize, while arguing that both brokerage and closure are forms of social capital, the book leads the reader to believe that brokerage is more useful and valuable because it bestows benefits on the broker, but also because closure can be dangerous to groups, leading to rigidity and distorted perceptions. Burt’s grand finale of his book states it all: “When you have an opportunity to learn how someone in another group does what you do differently—go.” [i.e., when you have an opportunity to broker a relationship] (p. 245). 4. Opening Burt’s network paradigm: areas for future development In the introduction to “brokerage and closure”, Burt says, “I cover diverse sources of evidence, however, I focus on organizations and managers” (p. 5). This is both a strength and a weakness of the book. Focusing on managers in organizations provides Burt with good quality data, but also constrains his ability to infer to other kinds of social situations. Using a similar method to examine structural holes provides him with an opportunity to collapse his samples and formalize his stylized facts, but it also limits the generalizations of his theory to other methods and to other definitions of structural holes. In this section, we propose six ways in which structural hole theory can be extended by future research. 4.1. Incorporate culture into structural hole theory Burt follows Emirbayer and Goodwin (1994) in suggesting that social network analysis should “pay more attention to culture as a reality-structuring mechanism” because culture “can discourage otherwise beneficial action” (p. 238). Unfortunately, Burt’s only attempt to deal with the ways
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culture influences the social capital potential of structural holes is provided in Chapter 1 (p. 50) when he describes a study comparing French and American managers (Burt et al., 2000). He concludes that while there are some differences between cultures, “brokers do better” (stylized fact #1). However, his data pertains solely to managers from Western cultures. The generalizability of stylized fact #1 would benefit from further research in other cultures. While there may be benefits associated with brokering relationships between different groups (such as groups in conflict, or groups unaware of each other), in some instances of cross-cultural brokerage, benefits may not accrue to the person spanning the structural hole. For example, people who tried to span structural holes between Arabs and Israelis often have not gained any personal benefits from their attempts. As an extreme example, Israeli Prime Minister Itzhak Rabin was assassinated for such an attempt in 1995, and history is filled with other examples of people attempting to broker relations between cultures and paying personal prices for their attempts. Burt’s first stylized fact, that “brokers do better,” is therefore not a truism because it is culture and situation dependent. An important future step in defining the scope of Burt’s theory better would be to integrate cross-cultural perspectives and social psychological theories that pertain to groups, conflict and intergroup relations. 4.2. Include individual agency and motivations Emirbayer and Goodwin’s article, presented above, is more elaborate than Burt’s description of it suggests, since it also argues that individual agency should be incorporated into social network analysis to explain network processes better. Burt briefly raises the issue of the entrepreneur’s personality in Chapter 1 (pp. 47–50). His discussion, based on Burt et al. (1998) suggests that people occupy structural holes to further their own agenda. The evidence he provides suggests that people should seek and occupy structural holes because that way they progress through the organization: “Everyone should optimize their access to structural holes” (p. 27). He implies that the brokers’ motivation is often to enhance themselves (e.g., “In brokerage, the object of action is you, improving your vision and helping escape the demands of other people”, p. 163). Conversely, when Burt describes closure, he often uses language that denies individual agency: “People in a closed network are expected to work harder, longer and with better quality” and “Network closure forces people to collaborate” (p. 163). Recent research (e.g., Kalish and Robins, 2006; Obstfeld, 2005) shows that other motivations besides self-enhancement may pertain to occupying structural holes. David Obstfeld suggests that people occupy structural holes in order to better integrate cliques across an organization. They act not for their own benefit, but rather for the benefit of the entire organization (Obstfeld calls this motivation Tertius iungens – the third who connects – in opposition with Simmel’s Tertius gaudens, the third who wins, a motivation that is the core of Burt’s ideas regarding brokerage, see Burt, 1992). A similar theoretical distinction between occupying structural holes for your own good and occupying them for the good of the larger social unit is drawn by Newell et al. (2004). Kalish and Robins (2006) find an association between occupying structural holes and the psychological trait of neuroticism. They argue that people who occupy structural holes between strongly tied network partners attempt to use divisive strategies to alleviate their psychological distress and fear of alters “ganging up” on them. Thus, people who occupy structural holes may not necessarily act from self-enhancing motivations. They may be reacting to psychological distress (as Kalish and Robins suggest), or they may be attempting to make the larger social unit do better (as Obstfeld argues). In other words, in addition to Burt’s argument that “people who have
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relations that span the structural holes between groups have a vision advantage in detecting and developing good ideas” (p. 245), people’s vision or fear may drive them to occupy structural holes. In accordance with Emirbayer and Goodwin (1994) suggestion, Burt’s theory may benefit from better explicating of agency. Future research might attempt to address the motivations underlying people in different network positions. 4.3. Expand the definition of structural holes Burt suggests that “a structural hole is an empty space across which you can see the other side” (p. 245). Thus, a relationship that spans a structural hole is one in which there is “no positive indirect contact between mutual contacts” (p. 24). Yet, this is only one definition of a structural hole. Others are possible as well, and Burt’s theory of structural holes will become more complete if other definitions are integrated into it. While acknowledging that the idea of structural holes is based on the sociology of Simmel (p. 17), Burt uses only one of the network positions that (according to Simmel) accrue power to the individual. Simmel (1950) argues that similar (control) benefits accrue to an individual who links two alters in a negative relationship or in no relationship. Thus, structural holes may exist as either “empty spaces” or as negative ties between alters and/or groups. Both types of structural holes act as “buffers, like an insulator in an electric circuit. . . people on either side circulate in different flows of information” (Burt, 2005, p. 16). Burt’s theory and future research would benefit from an examination of whether the same stylized facts hold for negative-tie structural holes as well. Burt distinguishes active from passive structural holes—an idea similar to the “depth” of structural holes (Burt, 1992). However, a more extensive typology of structural holes can be achieved by examining the potential of gains for the broker. Some structural holes may prevent high-return ties between two unconnected actors while other holes may be perceived as low-return (uninteresting) to bridge. The former are more attractive to network entrepreneurs than the latter. Further development of the attractiveness of bridging potential structural holes will allow a more complete understanding of when and why brokerage and closure occur. 4.4. Acknowledge the formal aspects of organizations in understanding structural holes Methodologically, Burt follows traditional network strategies in differentiating between organizational charts, company regulations and official procedures and informal network structures. Burt sets out to learn about the organization of firms – and their opportunity structures – solely through managers’ reports of discussion networks. In doing so, however, he ignores the a priori fact that managers are embedded within departments or units. He thus ignores the fact that (at least some) structural holes in the company are purposefully constructed by company engineers and policed by senior officials, and that holes may be enforced by secrecy regulations and formal command lines. In Chapter 5, Burt differentiates between active and passive structural holes. However, his research does not capture this distinction. Active structural holes may result from formal organizational structures that are enforced by regulations and policies. Thus, they may not allow for brokerage or may even harm the broker. An analysis of the types of structural holes that can be brokered – possibly using exponential random graphs (p*) models with node attributes (Robins et al., in press) or models of social selection (e.g., Robins et al., 2001) – may enhance our understanding of the conditions under which brokerage is possible and valuable.
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4.5. Examine tie strength While Burt does not examine the possibility that negative ties may create structural holes, he does address negative ties in relation to closure. In doing so, he equates negative ties with distrust (as part of the Echo argument, Chapter 4). Specifically, he argues that strong negative relationships should generate more distrust. However, research into ambivalent (strong and negative) ties suggests that these ties may not be characterized by distrust, but rather by a mixture of trust and conflict (e.g., Kalish, 2006; Oliver, 2004; Uchino et al., 2004). If strong negative ties are trust-worthy (yet difficult) ties, Burt’s arguments regarding the difference between Echo and Bandwidth may need further elaboration. 4.6. Utilize other network methods and indicators In most of his analyses, Burt uses an index of network constraint that he has developed: a “concentration measure that varies from 0 to 100 with the extent to which all of a person’s network time and energy is concentrated in one single contact” (p. 27) to examine the structural holes surrounding a focal individual. The use of egocentric network methods opens research to criticisms regarding the reliability of perceptions. More research using complete networks (in which indices such as betweenness centrality are available) would have grounded Burt’s theory in cross-validated perceptions. Organizations constitute an advantageous context for measuring complete networks, and we suggest using this potential in further research. Furthermore, by using only network constraint to examine respondents’ local network, it is impossible to examine cycles of four (or more) members that have been shown to relate to the development of trust in organizations (Lazega and Pattison, 1999). Future research might examine whether the stylized facts that pertain to closure and brokerage are still appropriate in complete networks, while accounting for larger cycles. There also has been some debate about the efficacy of network constraint (e.g., Borgatti, 1997), and the correlation of network constraint with network size makes comparisons across networks difficult. For example, Kalish and Robins (2006) show that by summing over strong and weak ties, network constraint may be too concentrated to reveal subtle differences between different types of structural holes and their association with the psychological predispositions of their occupant. Future research would benefit from utilizing other measures to examine the existence of structural holes around focal individuals. To summarize, Burt’s Brokerage and Closure is a persuasive tour-de-force that provides an extensive holistic introduction of Burt’s ideas regarding social capital. And Burt’s ideas warrant attention. As we presented in Section 2, his ideas are contagious, have had tremendous impact, and are now migrating to different disciplines—possibly the result of Burt having both (sociological) closure and brokerage (to others). We eagerly anticipate Burt’s (and others’) work that will further expand the theory of brokerage into other structural, conceptual, interdisciplinary and theoretical directions. References Borgatti, S.P., 1997. Structural holes: Unpacking Burt’s redundancy measures. Connections 20 (1), 35–38. Burt, R.S., 1982. Toward a Structural Theory of Action: Network Models of Social Structure, Perception, and Action. Academic Press, New York. Burt, R.S., 1983. Corporate Profits and Cooptation: Networks of Market Constraints and Directorate Ties in the American Economy. Academic Press, New York.
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Burt, R.S., 1992. Structural Holes: The Social Structure of Competition. Harvard University Press, Cambridge, MA. Burt, R.S., 1998. Personality correlates of structural holes. In: Kramer, R.M., Neale, M.A. (Eds.), Power and Influence in Organizations. Sage, Thousand Oaks, pp. 221–250. Burt, R.S., 2004. Structural holes and good ideas. American Journal of Sociology 110, 349–399. Burt, R.S., 2005. Brokerage and Closure: An Introduction to Social Capital. Oxford University Press. Burt, R.S., Jannotta, J.E., Mahoney, J.T., 1998. Personality correlates of structural holes. Social Networks 87 (20), 63. Burt, R.S., Hogath, R., Michaud, C., 2000. The social capital of French and American managers. Organization Science 11, 123–147. Emirbayer, M., Goodwin, J., 1994. Network analysis, culture and the problem of agency. American Journal of Sociology 145 (99), 1411. Kalish, Y., 2006. People and networks. Unpublished PhD Dissertation. University of Melbourne. Kalish, Y., Robins, G.L., 2006. Psychology, agency and network structure: relating psychological predispositions to structural holes and network closure. Social Networks 26 (1), 56–84. Lazega, E., Pattison, P.E., 1999. Multiplexity, generalized exchange and cooperation in organizations: a case study. Social Networks 90 (21), 67. Newell, S., Tansley, C., Huang, J., 2004. Social capital and knowledge integration in an ERP project team: the importance of bridging and bonding. British Journal of Management 15, S43–S57. Obstfeld, D., 2005. Social networks, the Tertius iungens orientation and involvement in innovation. Administrative Science Quarterly 50, 100–130. Oliver, A.L., 2004. On the duality of competition and collaboration: network based knowledge relations in the biotechnology industry. Scandinavian Journal of Management 20, 151–171. Robins, G., Pattison, P., Kalish, Y., Lusher, D., in press. A workshop on exponential random graph (p*) models for social networks. Social Networks. Robins, G.L., Elliott, P., Pattison, P., 2001. Network models for social selection processes. Social Networks 30 (23), 1. Simmel, G., 1950. The Sociology of Georg Simmel. Free Press, Glencoe, IL. Simmel, G., 1990. The Philosophy of Money. Routledge, London. Uchino, B.N., Holt-Lunstad, J., Smith, T.W., Bloor, L., 2004. Heterogeneity in social networks: a comparison of different models linking relationships to psychological outcomes. Journal of Social and Clinical Psychology 139 (23), 123.
Amalya L. Oliver ∗ Yuval Kalish Gad Yair Department of Sociology and Anthropology, The Hebrew University, Jerusalem, Israel ∗ Corresponding
reviewer.
E-mail address: [email protected] (A.L. Oliver)
Book review Reflections on “Brokerage and Closure” Brokerage and Closure: An Introduction to Social Capital, R.S. Burt. Oxford University Press (2005) 1. Structural holes—an overview The publication of Ronald S. Burt’s Brokerage and Closure: An Introduction to Social Capital (Oxford University Press, 2005) is cause for celebration among network enthusiasts. In this excellent new addition to the expanding literature on social capital and organization studies, Burt provides an extensive introduction to his theory of social capital. The book is well written, comprehensive and persuasive, and it summarizes the theory of one of the most influential and cited scholars in the field. Structured around four main chapters, two dealing with brokerage as social capital and two with closure as social capital, the book is a detailed account of Burt’s research activities and theorizing to date. Readers who are familiar with Burt’s work and his teaching materials in the last 10 years will find themselves on familiar grounds. Yet, the book is the most complete presentation of his ideas regarding structural holes to date. Readers new to the idea of social capital will get an extensive, clearly written, compelling introduction, especially as it pertains to Burt’s ideas about brokerage as social capital. However, the book is not an introductory textbook. While it does not include complex methodological notes as part of the main text, appreciating the complexity of Burt’s ideas require the reader to be well versed in social sciences methodology and theory and to have some familiarity with social network analysis, especially with network indices and structures. We take the opportunity of celebrating Burt’s new book to review Burt’s academic career in terms of brokerage and closure, and to reflect on the theory of social capital as presented in the book. Therefore, this review is structured in three sections: first, we provide a brief intellectual and professional context for this book. Specifically, we argue that in concordance with the book’s main argument, Burt has reaped the benefits of brokering relationships between academic disciplines. Second, we provide a brief summary of the book. Third, we attempt to open Burt’s rigorous business-oriented sociology in ways that might enrich organizational studies specifically, and network theory generally.
0378-8733/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.socnet.2007.01.001
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2. Brokerage and closure in Burt’s publication trajectory Ronald Burt’s book continues his long-standing interest in strategies of advantage in competitive markets. Over the past three decades Burt used several studies to investigate different aspects of “brokerage-as-social capital”. He has focused, for example, on gains in competitive markets, on manager promotion rates (Burt, 1992), on personality correlates of structural holes (Burt, 1998), and on the good ideas inherent in bridging structural holes (Burt, 2004). He consistently shows that people who bridge the holes between different social worlds (groups, cliques) enjoy the advantage of having good ideas because they have a broader vision than people with constrained networks. Stemming from this vision advantage, people with access to structural holes enjoy the potential of gaining an advantage by capitalizing on their good ideas. Burt’s pragmatic interest in profitability was clearly stated in the overriding questions he posed in his earlier work: How does the structure of competitive buying and selling among organizations actually operate to constrain corporate profits? How could that competition be brought under control by the existence of non-market connections between organizations? To what extent has it been brought under control? These are my central concerns in this book (Burt, 1983, p. 2). More than 20 years later, his commitment is the same: understanding “the problems of how to create value” (2005, p. 8). We highlight two theoretical positions that we suggest are essential for Burt. The first is the idea of rational agent and the second is the idea of social structure enabling action. In his early theoretical statements, Burt aligns himself with Coleman in suggesting a general theory of action. In that context, Burt explicated his assumptions about the nature of action: My experiences with people lead me to hold two beliefs as a fruitful foundation for constructing systematic social theory. First, people as individual or group actors are purposive, in the sense of using their resources to realize their interests. Second, these purposive actors pursue their interests in the context of social structure generated by the division of labor in society (Burt, 1982, p. ix). For Burt, organizations constitute opportunity structures, and he assumes that rational actors actively seek opportunities for securing advantage by using the information that flows through their position and by controlling the action of others. We return to this point in section 4, when we propose ways in which the theory can be extended. The second theoretical tenet bears similarity with Simmel’s structural analyses of social positions as “forms” or types of social relations (e.g., the dyad and triad). Simmel suggested that people with opportunity structures of the Tertius gaudens (the position of the third party who wins) develop a “stranger” mentality: a broader vision, objectivity, coldness and manipulability (Simmel, 1950, 1990). Burt expands on this insight by arguing that social positions in heterogeneous settings provide opportunities and limitations on action by affecting two main sources of power: information and control. Those actors who find themselves in positions with non-redundant sources of information can gain an edge in competitive economic markets by making strategically smart moves in organizations. Utilizing these two tenets, and borrowing ideas from other sociologists (such as David Krackhardt and Mark Granovetter) and economists (such as Frederick Hayek and Joseph Schumpeter), Burt developed his theory of structural holes, described at length in Section 3. His main concern
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Fig. 1. Citation patterns by year and discipline.
remains how to “create value” while assuming rational agents and the social structures in which they are embedded. During the past three decades, he has written six books, about 65 journal articles and 15 book chapters, most of them focused on the interplay between social positions and advantage in organizations.1 He employs conceptual wizardry – minting or creatively using concepts such as social capital, structural holes, structural autonomy, network closure, bandwidth, echo, rigidity, equilibrium and inertia – for a better understanding of hindrances on market efficiency and of entrepreneurial opportunities in competitive organizational arenas. A bird’s eye view of Burt’s publications shows a consistent decline in their number across the first three decades of his career, compensated by a growing trend of citations. In terms of content, the trajectory of his publications suggests that after a very ripe methodological period (ending in 1983), Burt focused his energies on developing his own theoretical approach, epitomized by his 1992 book, Structural Holes. Clearly this has been the most cited of his works: as of June 2006 the book was mentioned 1598 times in Google Scholar). From 1992 onward, his publications focus on attempts at integration, synthesis and application. As of 1995, Burt often uses “social capital” to position his own take on this popular concept, predominantly vis-`a-vis the work of James Coleman who popularized the concept in sociology. A focused look at the places where Burt published his articles suggests that he has largely concentrated his publications in a single journal, Social Networks: home to 21 (32%) of all his journal articles. Other major outlets are Social Science Research (11%), and the American Journal of Sociology, Social Forces, and Sociological Methods & Research—each housing 5 (8%) of his 65 refereed papers. This concentration – and the fact that only 8 (12%) of his papers have appeared in organizational journals – show that Burt’s publication efforts have been focused on the discipline of sociology, despite his prominence among organization scientists and his position in the Chicago Graduate School of Business. In Burtian terms, he enjoys a closed sociological network, in which (as he argues in his new book), trust and reputation can emerge. However, in terms of impact, Burt has been successful at brokering his ideas to the world of organizational analysis. Citations to his articles by discipline (Fig. 1) suggest that his ideas
1
Based on information from Burt’s website: www.gsb.uchicago.edu/fac/Ronald.burt (accessed on April 2006).
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have been gaining acceptance across disciplinary borders. While his early publications were mostly cited in sociology journals (63% of the total cites for 1975–1985 were in sociological journals and 24% in business and management journals), his later publications were mostly cited in management and business journals (only 28% of the total cites for 1996–2005 were in sociological journals while 65% were in management and business journals). Ronald Burt’s attempt to broker between academic disciplines is similarly evident in his efforts to broker ties between academia and business organizations. He has provided executive education to firms like BMW, Cable & Wireless, Exxon, IBM, and L’Oreal. Most importantly, he was Director of the Raytheon Leadership Institute (2000–2003) and Vice-President of Strategic Learning at Raytheon (2001–2003). Burt is clearly a man who walks the talk and practices what he preaches. It comes as no surprise, therefore, that in his new book Burt pays much attention to the importance of brokerage as social capital. It is what he does best and what has generated his many good ideas. Yet, as we argue later, Burt’s pragmatic orientations and focus on the business world may have also produced closure in his theoretical foci. 3. The themes of the book Brokerage and Closure is rich and dense with ideas, evidence and corroborations. Four chapters form its core: two dealing with brokerage as social capital and two with closure as social capital. Each chapter begins with the description of studies conducted by Burt and colleagues, continues with extensive evidence and corroborations from other disciplines, and closes with a stylized fact: a slogan that provides a summary of the chapter. Moreover, in the course of reading the book, readers cannot avoid the impression that the book leads them through various sources of evidence that are robustly connected to each other. At times, they may feel too well connected. Below we present a brief summary of the main arguments in the book. The introduction contrasts brokerage and closure and suggests that optimizing for closure (operationalized as within-group contact volume) is inefficient. Burt asserts that informal organizations are composed of dense social clusters with occasional bridge relations connecting them. Since opinions and practices are more similar within groups than between groups, a person who brokers relations across a structural hole has the advantage of early access to knowledge and opportunities for coordinating across groups—a social capital advantage. This advantage translates into more positive evaluations, early promotion and higher compensation. Thus, “brokers do better”—Burt’s first stylized fact. According to Burt, brokerage positions have more advantages—they provide visions of options otherwise unseen. In essence, “brokerage puts people in a position to learn about things they didn’t know they didn’t know” (p. 59). Thus, Burt’s second argument (Chapter 2) is that people who occupy structural holes have better ideas. Brokerage is presented as a multi-level phenomenon through which a person could create value. Thus, value could be created through awareness of the complexities that other groups are faced with, transferring best practices to the other groups, drawing analogies between the two groups, and synthesizing ideas present in both groups. This vision advantage helps brokers to use their positions to generate new beliefs or behaviors that synthesize elements from both groups. As evidence, Burt presents data that is based on relationships between managers in a large supply chain firm discussing ideas for improvement. This idea is then strengthened by research from other disciplines, and is summed by Burt’s second stylized fact: “Improved vision is the mechanism responsible for returns to brokerage”. In the first two chapters, the reader is left with the impression that brokerage is the only mechanism associated with social capital. The next two chapters deal with the advantages of closure
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as social capital. Burt asserts that the trust needed to realize the value of bridging structural holes is ensured by network closure: “Brokerage is about coordinating people between whom it would be valuable, but risky, to trust. Closure is about making it safe to trust” (p. 97). Based on ideas by Simmel, Krackhardt, Granovetter and Coleman, Burt argues that in situations where trust is an advantage, there is social capital in closure. In fact, embedding a tie in multiple, strong third party ties (i.e., creating Simmelian ties and closure) enhances social control through reputation. The working hypothesis for this chapter is that “strong and positive third party relations between two people invoke closure’s reputation mechanism, which lowers the risk for either person trusting the other, making trust more likely” (p. 112). Since closure is “about making it safe to trust” and brokerage is “about coordinating people between whom it would be valuable, but risky, to trust”, the chapter suggests combining the two: namely, the social capital of structural holes depends on trust to deliver the value created by brokerage. Thus, the third stylized fact is that performance is a product of brokerage outside the group and closure inside the group. Having convinced us that both closure and brokerage are valuable to performance, Burt examines how trust is generated by closure, by comparing the “Bandwidth” and “Echo” hypotheses. His Bandwidth hypothesis argues: “Strong, redundant connections ensure a reliable flow of data so that everyone in the network is informed about behavior that enhances or erodes reputation” (p. 167). The hypothesis suggests that dense networks enhance flow of consistent information across the network. Third parties “had no motive” (p. 168) to disclose information. They are simply viewed as pipes through which information flows. Thus, according to Bandwidth, trust is the result of consistency of information across the network. The Echo hypothesis, on the other hand, is based on “the social psychology of selective disclosure in informal conversations”, whereby “third parties communicate a sample of what they know, a sample defined by etiquette” (p. 168). Contrary to Bandwidth, Echo provides people with a “motive”, following the rules of etiquette (see pp. 172–178). Burt argues that people are motivated by social etiquette, and as a result selectively filter and reproduce information with gossip. This reproduction of information in closed networks not only creates consistency of information across the network (i.e., Bandwidth), it also creates more intense feelings in which perceptions are constantly reinforced by networks and therefore become further removed from reality. The data presented in this chapter provide evidence that the Echo hypothesis is more accurate than the Bandwidth hypothesis. Closure is not only associated with better control (peer pressure) of behavior, but due to the Echo mechanism, closure also creates increasingly more biased perceptions of third parties. As a result, new relations between friends of friends are protected from tie decay. These relations are likely to survive to maturity, reinforcing the existing structure through increased density within clusters, which in turns leads to further echoing of perceptions. In addition, it leads to increased distance between clusters coupled with increased rigidity within clusters. The stylized fact for the fourth chapter is that gossip and reputation have a strong, possibly insidious effect in closed networks, and they create rigid, stale, and closed cliques. Questions regarding equilibrium and the costs and benefits of brokerage and closure were highly needed at this stage of the book. The fifth chapter, the most innovative of the book, is about change and inertia in network structures. Here, Burt adds time to the structural dimension in order to hypothesize about the development of network structures longitudinally. Bringing into discussion the Austrian school’s market metaphors of Schumpeter and Hayek, he argues that since information is always imperfect and incomplete, there is a premium given to people
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who are network entrepreneurs. These entrepreneurs create valuable knowledge combinations from knowledge that is otherwise segregated in separated groups. Equilibrium is reached when the benefits associated with creating new combinations (brokerage) are balanced by the price paid for integrative work. For early entrepreneurial bridging, the returns for integration are highly disproportional; while for successive bridges built across structural holes, the returns diminish. The price paid for (and benefits associated with) brokering is partially the result of another important distinction Burt draws: between active and passive structural holes. Based on Charles Tilly’s work, Burt defines a structural hole as active if interests attached to the hole resist bridges (e.g., in cases in which competing interests to bridge a hole erode each other). He sees four mechanisms that keep structural holes active: (1) if they provide opportunities of insiders to exploit outsiders; (2) if they permit insiders to hoard opportunities from outsiders; (3) if insiders can establish new organizations in which insiders are at an advantage; (4) if routines, social, information, and influence ties have adapted to the hole. Conversely, Burt defines a hole as passive if information flows freely across it, thus diminishing the value of subsequent bridges. Implied in his distinction is that slow moves to equilibrium are associated with active holes and therefore offer brokers longer advantages. Burt treats equilibrium as a local balance between closure – pulling towards conformity and rigid structure, and brokerage – pulling outside groups towards change and new ideas. Closure has internal stabilizing forces that are typically stronger compared with brokerage. Yet brokerage has the potential to bring endogenous change. The pull towards the group suggests that structural holes are perceived as empty space until entrepreneurs find value in coordinating across the holes. At that point, a new process towards equilibrium commences, with more and more people spanning the structural hole with diminishing returns until a new equilibrium is reached. To summarize, while arguing that both brokerage and closure are forms of social capital, the book leads the reader to believe that brokerage is more useful and valuable because it bestows benefits on the broker, but also because closure can be dangerous to groups, leading to rigidity and distorted perceptions. Burt’s grand finale of his book states it all: “When you have an opportunity to learn how someone in another group does what you do differently—go.” [i.e., when you have an opportunity to broker a relationship] (p. 245). 4. Opening Burt’s network paradigm: areas for future development In the introduction to “brokerage and closure”, Burt says, “I cover diverse sources of evidence, however, I focus on organizations and managers” (p. 5). This is both a strength and a weakness of the book. Focusing on managers in organizations provides Burt with good quality data, but also constrains his ability to infer to other kinds of social situations. Using a similar method to examine structural holes provides him with an opportunity to collapse his samples and formalize his stylized facts, but it also limits the generalizations of his theory to other methods and to other definitions of structural holes. In this section, we propose six ways in which structural hole theory can be extended by future research. 4.1. Incorporate culture into structural hole theory Burt follows Emirbayer and Goodwin (1994) in suggesting that social network analysis should “pay more attention to culture as a reality-structuring mechanism” because culture “can discourage otherwise beneficial action” (p. 238). Unfortunately, Burt’s only attempt to deal with the ways
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culture influences the social capital potential of structural holes is provided in Chapter 1 (p. 50) when he describes a study comparing French and American managers (Burt et al., 2000). He concludes that while there are some differences between cultures, “brokers do better” (stylized fact #1). However, his data pertains solely to managers from Western cultures. The generalizability of stylized fact #1 would benefit from further research in other cultures. While there may be benefits associated with brokering relationships between different groups (such as groups in conflict, or groups unaware of each other), in some instances of cross-cultural brokerage, benefits may not accrue to the person spanning the structural hole. For example, people who tried to span structural holes between Arabs and Israelis often have not gained any personal benefits from their attempts. As an extreme example, Israeli Prime Minister Itzhak Rabin was assassinated for such an attempt in 1995, and history is filled with other examples of people attempting to broker relations between cultures and paying personal prices for their attempts. Burt’s first stylized fact, that “brokers do better,” is therefore not a truism because it is culture and situation dependent. An important future step in defining the scope of Burt’s theory better would be to integrate cross-cultural perspectives and social psychological theories that pertain to groups, conflict and intergroup relations. 4.2. Include individual agency and motivations Emirbayer and Goodwin’s article, presented above, is more elaborate than Burt’s description of it suggests, since it also argues that individual agency should be incorporated into social network analysis to explain network processes better. Burt briefly raises the issue of the entrepreneur’s personality in Chapter 1 (pp. 47–50). His discussion, based on Burt et al. (1998) suggests that people occupy structural holes to further their own agenda. The evidence he provides suggests that people should seek and occupy structural holes because that way they progress through the organization: “Everyone should optimize their access to structural holes” (p. 27). He implies that the brokers’ motivation is often to enhance themselves (e.g., “In brokerage, the object of action is you, improving your vision and helping escape the demands of other people”, p. 163). Conversely, when Burt describes closure, he often uses language that denies individual agency: “People in a closed network are expected to work harder, longer and with better quality” and “Network closure forces people to collaborate” (p. 163). Recent research (e.g., Kalish and Robins, 2006; Obstfeld, 2005) shows that other motivations besides self-enhancement may pertain to occupying structural holes. David Obstfeld suggests that people occupy structural holes in order to better integrate cliques across an organization. They act not for their own benefit, but rather for the benefit of the entire organization (Obstfeld calls this motivation Tertius iungens – the third who connects – in opposition with Simmel’s Tertius gaudens, the third who wins, a motivation that is the core of Burt’s ideas regarding brokerage, see Burt, 1992). A similar theoretical distinction between occupying structural holes for your own good and occupying them for the good of the larger social unit is drawn by Newell et al. (2004). Kalish and Robins (2006) find an association between occupying structural holes and the psychological trait of neuroticism. They argue that people who occupy structural holes between strongly tied network partners attempt to use divisive strategies to alleviate their psychological distress and fear of alters “ganging up” on them. Thus, people who occupy structural holes may not necessarily act from self-enhancing motivations. They may be reacting to psychological distress (as Kalish and Robins suggest), or they may be attempting to make the larger social unit do better (as Obstfeld argues). In other words, in addition to Burt’s argument that “people who have
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relations that span the structural holes between groups have a vision advantage in detecting and developing good ideas” (p. 245), people’s vision or fear may drive them to occupy structural holes. In accordance with Emirbayer and Goodwin (1994) suggestion, Burt’s theory may benefit from better explicating of agency. Future research might attempt to address the motivations underlying people in different network positions. 4.3. Expand the definition of structural holes Burt suggests that “a structural hole is an empty space across which you can see the other side” (p. 245). Thus, a relationship that spans a structural hole is one in which there is “no positive indirect contact between mutual contacts” (p. 24). Yet, this is only one definition of a structural hole. Others are possible as well, and Burt’s theory of structural holes will become more complete if other definitions are integrated into it. While acknowledging that the idea of structural holes is based on the sociology of Simmel (p. 17), Burt uses only one of the network positions that (according to Simmel) accrue power to the individual. Simmel (1950) argues that similar (control) benefits accrue to an individual who links two alters in a negative relationship or in no relationship. Thus, structural holes may exist as either “empty spaces” or as negative ties between alters and/or groups. Both types of structural holes act as “buffers, like an insulator in an electric circuit. . . people on either side circulate in different flows of information” (Burt, 2005, p. 16). Burt’s theory and future research would benefit from an examination of whether the same stylized facts hold for negative-tie structural holes as well. Burt distinguishes active from passive structural holes—an idea similar to the “depth” of structural holes (Burt, 1992). However, a more extensive typology of structural holes can be achieved by examining the potential of gains for the broker. Some structural holes may prevent high-return ties between two unconnected actors while other holes may be perceived as low-return (uninteresting) to bridge. The former are more attractive to network entrepreneurs than the latter. Further development of the attractiveness of bridging potential structural holes will allow a more complete understanding of when and why brokerage and closure occur. 4.4. Acknowledge the formal aspects of organizations in understanding structural holes Methodologically, Burt follows traditional network strategies in differentiating between organizational charts, company regulations and official procedures and informal network structures. Burt sets out to learn about the organization of firms – and their opportunity structures – solely through managers’ reports of discussion networks. In doing so, however, he ignores the a priori fact that managers are embedded within departments or units. He thus ignores the fact that (at least some) structural holes in the company are purposefully constructed by company engineers and policed by senior officials, and that holes may be enforced by secrecy regulations and formal command lines. In Chapter 5, Burt differentiates between active and passive structural holes. However, his research does not capture this distinction. Active structural holes may result from formal organizational structures that are enforced by regulations and policies. Thus, they may not allow for brokerage or may even harm the broker. An analysis of the types of structural holes that can be brokered – possibly using exponential random graphs (p*) models with node attributes (Robins et al., in press) or models of social selection (e.g., Robins et al., 2001) – may enhance our understanding of the conditions under which brokerage is possible and valuable.
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4.5. Examine tie strength While Burt does not examine the possibility that negative ties may create structural holes, he does address negative ties in relation to closure. In doing so, he equates negative ties with distrust (as part of the Echo argument, Chapter 4). Specifically, he argues that strong negative relationships should generate more distrust. However, research into ambivalent (strong and negative) ties suggests that these ties may not be characterized by distrust, but rather by a mixture of trust and conflict (e.g., Kalish, 2006; Oliver, 2004; Uchino et al., 2004). If strong negative ties are trust-worthy (yet difficult) ties, Burt’s arguments regarding the difference between Echo and Bandwidth may need further elaboration. 4.6. Utilize other network methods and indicators In most of his analyses, Burt uses an index of network constraint that he has developed: a “concentration measure that varies from 0 to 100 with the extent to which all of a person’s network time and energy is concentrated in one single contact” (p. 27) to examine the structural holes surrounding a focal individual. The use of egocentric network methods opens research to criticisms regarding the reliability of perceptions. More research using complete networks (in which indices such as betweenness centrality are available) would have grounded Burt’s theory in cross-validated perceptions. Organizations constitute an advantageous context for measuring complete networks, and we suggest using this potential in further research. Furthermore, by using only network constraint to examine respondents’ local network, it is impossible to examine cycles of four (or more) members that have been shown to relate to the development of trust in organizations (Lazega and Pattison, 1999). Future research might examine whether the stylized facts that pertain to closure and brokerage are still appropriate in complete networks, while accounting for larger cycles. There also has been some debate about the efficacy of network constraint (e.g., Borgatti, 1997), and the correlation of network constraint with network size makes comparisons across networks difficult. For example, Kalish and Robins (2006) show that by summing over strong and weak ties, network constraint may be too concentrated to reveal subtle differences between different types of structural holes and their association with the psychological predispositions of their occupant. Future research would benefit from utilizing other measures to examine the existence of structural holes around focal individuals. To summarize, Burt’s Brokerage and Closure is a persuasive tour-de-force that provides an extensive holistic introduction of Burt’s ideas regarding social capital. And Burt’s ideas warrant attention. As we presented in Section 2, his ideas are contagious, have had tremendous impact, and are now migrating to different disciplines—possibly the result of Burt having both (sociological) closure and brokerage (to others). We eagerly anticipate Burt’s (and others’) work that will further expand the theory of brokerage into other structural, conceptual, interdisciplinary and theoretical directions. References Borgatti, S.P., 1997. Structural holes: Unpacking Burt’s redundancy measures. Connections 20 (1), 35–38. Burt, R.S., 1982. Toward a Structural Theory of Action: Network Models of Social Structure, Perception, and Action. Academic Press, New York. Burt, R.S., 1983. Corporate Profits and Cooptation: Networks of Market Constraints and Directorate Ties in the American Economy. Academic Press, New York.
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Burt, R.S., 1992. Structural Holes: The Social Structure of Competition. Harvard University Press, Cambridge, MA. Burt, R.S., 1998. Personality correlates of structural holes. In: Kramer, R.M., Neale, M.A. (Eds.), Power and Influence in Organizations. Sage, Thousand Oaks, pp. 221–250. Burt, R.S., 2004. Structural holes and good ideas. American Journal of Sociology 110, 349–399. Burt, R.S., 2005. Brokerage and Closure: An Introduction to Social Capital. Oxford University Press. Burt, R.S., Jannotta, J.E., Mahoney, J.T., 1998. Personality correlates of structural holes. Social Networks 87 (20), 63. Burt, R.S., Hogath, R., Michaud, C., 2000. The social capital of French and American managers. Organization Science 11, 123–147. Emirbayer, M., Goodwin, J., 1994. Network analysis, culture and the problem of agency. American Journal of Sociology 145 (99), 1411. Kalish, Y., 2006. People and networks. Unpublished PhD Dissertation. University of Melbourne. Kalish, Y., Robins, G.L., 2006. Psychology, agency and network structure: relating psychological predispositions to structural holes and network closure. Social Networks 26 (1), 56–84. Lazega, E., Pattison, P.E., 1999. Multiplexity, generalized exchange and cooperation in organizations: a case study. Social Networks 90 (21), 67. Newell, S., Tansley, C., Huang, J., 2004. Social capital and knowledge integration in an ERP project team: the importance of bridging and bonding. British Journal of Management 15, S43–S57. Obstfeld, D., 2005. Social networks, the Tertius iungens orientation and involvement in innovation. Administrative Science Quarterly 50, 100–130. Oliver, A.L., 2004. On the duality of competition and collaboration: network based knowledge relations in the biotechnology industry. Scandinavian Journal of Management 20, 151–171. Robins, G., Pattison, P., Kalish, Y., Lusher, D., in press. A workshop on exponential random graph (p*) models for social networks. Social Networks. Robins, G.L., Elliott, P., Pattison, P., 2001. Network models for social selection processes. Social Networks 30 (23), 1. Simmel, G., 1950. The Sociology of Georg Simmel. Free Press, Glencoe, IL. Simmel, G., 1990. The Philosophy of Money. Routledge, London. Uchino, B.N., Holt-Lunstad, J., Smith, T.W., Bloor, L., 2004. Heterogeneity in social networks: a comparison of different models linking relationships to psychological outcomes. Journal of Social and Clinical Psychology 139 (23), 123.
Amalya L. Oliver ∗ Yuval Kalish Gad Yair Department of Sociology and Anthropology, The Hebrew University, Jerusalem, Israel ∗ Corresponding
reviewer.
E-mail address: [email protected] (A.L. Oliver)