Who Do You Know in the Group?: Location of Organizations in Interpersonal Networks

This article demonstrates that interpersonal network density can serve as a resourcefor organizational processes. This theory relies upon the notion of organizational recruitment and the selection mechanisms of organizational ecology. Data on confiding relations between people are used to construct two demographic networks. A series of log-linear models arefitted to the data to test implications of the theory. In most cases, models which include parameters to capture the location of organizational niches significantly reduce the residual chi-square from independence and homophily models. Thus, partial support isfoundfor the basic premise of the theory, indicating that network density does serve as a resource for organizational survival. Further avenues for research are suggested. Individual lives evolve through a succession of organizational affiliations and interpersonal social networks. Organizational affiliations and the network in which an individual is embedded are inextricably related. Dynamic properties make this relation quite complicated. McPherson (1983, 1988, 1990; McPherson & Ranger-Moore 1991) has developed an ecological theory of.voluntary organizations that builds upon the relation between interpersonal networks and organizations. Ecological models of organizational dynamics rely on the notion of competition over resources to explain the emergence, growth, decline, and elimination of organizational populations. McPherson argues that the resource space for voluntary organizations consists of people who are potential members of the groups. His theory clearly recognizes the coevolutionary processes of friendship formation resulting from common organizational membership and organizational recruitment through interpersonal networks. Superimposing the network i) The University of North Carolina Press Social Forces, December 1991, 70(2):455-474 *The author would like to thank Ronald L. Breiger, Miller McPherson, Beth Rubin, Elizabeth West, David Barron and John Roberts for helpful comments on earlier versions of this article. Of course, the author should be held responsible for any shortcomings in the final product. Indeed, some of the people listed above might not recognize the present version of this article. An earlier version was presented at the 1989 annual meetings of the American Sociological Association in San Francisco. This content downloaded from 157.55.39.180 on Mon, 25 Apr 2016 06:33:14 UTC All use subject to http://about.jstor.org/terms 456 / Social Forces 70:2, December 1991 metaphor on organizational theory promises greater understanding of organizational processes. While initial work has demonstrated that competitive processes create populations of voluntary organizations (McPherson 1983; McPherson & SmithLovin 1987a), recent research has tested the implications of the theory at the microlevel of the organizational membership. This research has examined both the effects of organizational competition on the number of memberships an individual can maintain (McPherson, West & Barron 1989) and event history analyses of membership duration (McPherson & Popielarz 1990; McPherson, Popielarz & Drobnic 1990; Popielarz 1990) and formation (Drobnic 1990; McPherson, Popielarz & Drobnic 1990). This work provides a point of departure for an attempt to link two levels of social structure: (1) the level of organizational structure, and (2) the level of interpersonal network structure. In this article, I describe the nature of this link and derive testable hypotheses implied by an ecological theory of voluntary organizations. The formulation of these implications incorporates two important ideas in the organizational and network literature. First, I draw upon the concept of an organizational niche from the population ecology of organizations (Hannan & Freeman 1977, 1989). Second, organizations recruit new members from the social network ties of existing members. I examine the theoretical notion that structural properties most usually examined at the organizational level (i.e., organizational population dynamics and niche location) are affected by structural properties at the interpersonal network level (i.e., interpersonal network density). Organizational Ecology and the Niche The essential element of ecological models of organizations is that environmental conditions select some organizational forms for survival (Hannan & Freeman 1977). The particular combination of resources that provide for positive growth rates of organizational populations is called the niche (Hannan & Freeman 1989). The niche can be thought of as demarcating the location of the organizational population in the resource space.' Note, however, that the niche is a property of a population of organizations, not single organizations. In general, a population's niche will be located where the crucial resources are most concentrated. However, different organizational types will compete with each other over these resources either more or less successfully. While each organizational type might thrive best where the distribution of a resource is most concentrated, only some will be able to fully exploit the resource space. Competition over resources can be observed when the niches of two or more organizational populations overlap. Where two or more populations are competing over the same resource, one can expect greater niche overlap to occur at the densest part of the resource distribution. A particularly important resource for voluntary associations includes people as potential organizational members. Blau (1977) has argued that social forms are structured along demographic parameters such as age, race, and sex. Thus, the resource space for voluntary associations, consisting of the people living This content downloaded from 157.55.39.180 on Mon, 25 Apr 2016 06:33:14 UTC All use subject to http://about.jstor.org/terms Location of Organizations in Networks / 457 within a community, can be modeled as a multidimensional space defined by Blau's demographic parameters. The niche boundaries of a population of voluntary associations can be determined by the demographic characteristics of its members. An organization might be located in the resource space by the range of member characteristics along the dimensions of age, education, income, sex, ethnicity, or race (see Figure 1). The rationale behind constructing the range is to encompass the part of the resource space from which the organizational population draws the bulk of its members. For example, McPherson (1983) sets niche boundaries by using a three-standard-deviation window centered about the mean for relevant member characteristics.2 The places in the multidimensional space where most people in a community are located constitute the richest parts of the resource space. The ecological model suggests that population niches will be located at these numerically dense parts of the resource distribution. Consider a single dimension, age. Suppose that in a community there are more younger (22-32 years) and older (50-58 years) people than middle-aged people. Organizational niches ought to correspond to the location of these resource populations (see Figure 2). This notion is easily expanded to the multidimensional case, where an organizational niche will correspond to the numerically dense part of the joint distribution on the multiple dimensions.3 Network-Based Recruitment Most readers are likely to recall an introduction to a person, who would later become a good friend, at a meeting of a group to which both belonged. Spatial proximity is important for the formation of friendships (Festinger, Schachter & Back 1950; Newcomb 1961). Organizational settings provide such proximity, serving as opportunity structures for the formation of interpersonal network ties (McPherson & Smith-Lovin 1986). But in addition to being a place to meet friends, organizations are places where friends meet. One member of a friendship dyad may convince the other to join that member's organization. Many types of organizations specifically exploit this process, recruiting new members through the network ties of existing members. Such recruitment has been found for voluntary associations (Booth & Babchuk 1973; Drobnic 1990), religious cults and church groups (Stark & Bainbridge 1980), and social movements (Snow, Zurcher & Ekland-Olson 1980). Even employment contracts are generated in this manner (Granovetter 1974). Booth and Babchuk (1973) found that 77% of the subjects in a panel study on organizations reported that their affiliation came about as a result of personal networks. To recruit ten people who are strangers to each other, an organization will need to greatly replicate its efforts. These efforts will likely be diffuse and inefficient. For example, efforts will center on open publicity such as mailings, phone calls, posters, or potentially expensive advertising campaigns. Each successful recruitment will be independent of others. Suppose, however, that these ten people are friends and acquaintances of each other. Once the organization has secured a membership commitment from one of these ten people, the social ties between this person and the other nine This content downloaded from 157.55.39.180 on Mon, 25 Apr 2016 06:33:14 UTC All use subject to http://about.jstor.org/terms 458 / Social Forces 70:2, December 1991 FIGURE 1: Example of Organizational Niches in Two-dimensional Resource Space Organizational population 3 Education Organizational population 1 In Years Organizational population 2