“Distinguishing Influence Based Contagion from Homophily Driven Diffusion in Dynamic Networks” PNAS

Sinan Aral, Lev Muchnik andArun Sundararajan

ABSTRACT:

“Node characteristics and behaviors are often correlated with the structure of social networks over time. While evidence of this type of assortative mixing and temporal clustering of behaviors among linked nodes is used to support claims of peer influence and social contagion in networks, homophily may also explain such evidence. Here we develop a dynamic matched sample estimation framework to distinguish influence and homophily effects in dynamic networks, and we apply this framework to a global instant messaging network of 27.4 million users, using data on the day-by-day adoption of a mobile service application and users’ longitudinal behavioral, demographic, and geographic data. We find that previous methods overestimate peer influence in product adoption decisions in this network by 300–700%, and that homophily explains 50% of the perceived behavioral contagion. These findings and methods are essential to both our understanding of the mechanisms that drive contagions in networks and our knowledge of how to propagate or combat them in domains as diverse as epidemiology, marketing, development economics, and public health.”

Testing the famous “sacred canopy” argument in a social network, this article seems like a fascinating read.

Author: Matthew E., Brashears

Source: Social Networks, In Press, Corrected Proof, Available online 22 January 2010 (URL)

Abstract: This article evaluates the Durkheim/Berger argument that integration in a network of co-religionists protects against anomia. The 1985 General Social Survey network instrument is used to evaluate the effect of integration on anomia and the probability of unhappiness. Results indicate that contact with religiously homogeneous others paired with personal religious belief reduces anomia and the likelihood of unhappiness. Additionally, while ego/alter closeness is important, alter/alter closeness is not. These results suggest that individuals benefit from religious association more so than religious community. Additional analyses indicate that these results are unlikely to be due to homophily.

Expertise Directory Development, Shared Task Interdependence, and Strength of Communication Network Ties as Multilevel Predictors of Expertise Exchange in Transactive Memory Work Groups

Yuan, Y. Connie,  Fulk, Janet,  Monge, Peter R.,  Contractor, Noshir

Communication Research 2010 37: 20-47

Just out in the new issue of Communication Research – an article combining social psychology and social network theory to explore transactive  memory processes.

Communication Research

Article abstract:
“Building on Kozlwoski and Klein’s emergence framework, this research developed and tested a set of multilevel hypotheses regarding individual and team transactive memory processes in work teams. Literature from social psychology suggested hypotheses on how shared task interdependence influences individual expertise exchange. Social network theory suggested hypotheses that individual expertise exchange is channeled according to communication tie strength. Using data collected from 218 individuals from 18 organizational teams, the proposed hypotheses were tested using hierarchical linear modeling techniques. The results showed that at the individual level the relationship between directory development and expertise exchange was mediated by communication tie strength and moderated by shared task interdependence.Team-level variables also were significantly related to individual-level outcomes such that individual expertise exchange happened more frequently in teams with well-developed team-level expertise directories, as well as with higher team communication tie strength and shared task interdependence.”

Elsevier

The Social Networks journal has published the first of its two special issues on network dynamcis: Dynamics of Social Networks edited by Patrick Doreian, Tom A.B. Snijders.

From the editors:

“This journal issue contains the first of two connected special issues on Dynamics of Social Networks. This second special issue will appear later this year. For a rather long time, attention to dynamic aspects in Social Network Analysis took the form of descriptive studies. However, over the last fifteen years model-based approaches to studying network change have been flowering. Landmarks were three special issues on Network Evolution of the Journal of Mathematical Sociology, edited by Frans Stokman and Patrick Doreian, in 1996 (with a book version: Doreian and Stokman, 1997 In: P. Doreian and F.N. Stokman, Editors, Evolution of Social Networks, Gordon and Breach Publishers, Amsterdam (1997).Doreian and Stokman, 1997), 2001, and 2003. These three special issues demonstrated how formal and statistical modeling and empirical analysis were coming together. The 2001 and 2003 special issues were focused on joining of theoretical developments with the analysis of empirical data using advanced modeling. This special issue presents a continuation of jointly using theories and modeling to understand social network phenomena.”

Historical network analysis out of Stanford University maps the exchange of thousands of letters in the 18th century’s “Republic of Letters”:

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If you haven’t done so already, this is a reminder to check out the September issue of the American Politics research journal which we previously mentioned in this post.

The  September 2009 theme issue is titled “Social Networks and American Politics.” The issue draws on work presented at the first “Networks in Political Science” conference held at Harvard University in 2008 and co-chaired by David Lazer and James Fowler. In the introductory article, Michael T. Heaney and Scott D. McClurg write:

“…network analysis has expanded during the last decade within the study of American politics, contributing to knowledge about political institutions, behavior, and network theory. Promising directions for future research include the study of power, preference aggregation, information flow and transaction costs, and network dynamics.”

The issue features research on the influence of networks on political institutions and political behavior, the use of game theory and network theory to explain coordination problems, and the role of interdependence and density dependence in political networks.

The table of contents for the theme issue can be found here:

http://apr.sagepub.com/content/vol37/issue5/

Change and External Events in Computer-Mediated Citation Networks: English Language Weblogs and the 2004 U.S. Electoral Cycle

James Moody announces the publishing of a new blog network paper by Carter Butts and Remy Cross in the Journal of Social Structure.

Journal of Social Structure

From the authors:

“This study examines global patterns of stability and change within six longitudinal samples of English-language weblogs (or “blogs”) during the 2004 U.S. Presidential election campaign. Using distance-based methods of graph comparison, we explore the evolution of the blog-blog citation networks for each sample during the period. In addition to describing the qualitative dynamics of the blog networks, we relate major campaign events (e.g., party political conventions and debates) to the observed pace of change. As we demonstrate, such events are associated with substantial differences in overall network volatility; moreover, volatility is also shown to have strong seasonal and endogenous components. Our findings suggest that external factors (both regular and episodic) may be important drivers of network dynamics.”