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Information Systems Research Forum
Three seminars with Sinan Aral
NYU Stern School of Business & MIT
Video of Network Structure and Information Advantage: The Diversity–Bandwidth Tradeoff
1. Bridging the gap between US and Europe: An informal chat on IS Research and Careers
Thursday 9 July
1600-1730
NAB room 4.21
Chair: Carsten Sorensen, ISIG, LSE
2. Identifying contagions in dynamic networks by distinguishing peer influence from homophily
Organised jointly with the Centre for Economic Performance
Tuesday 7 July
1245-1400
Library room R407
Node characteristics and behaviours are often correlated with the structure of social networks over time. While evidence of this type of assortative mixing and temporal clustering of behaviours amongst 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 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 behavioural, demographic and geographic data. We find that previous methods overestimate peer influence in product adoption decisions in this network by up to 700% and that homophily explains over 50% of the perceived behavioural contagion. These findings are essential to both our understanding 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.
3. Network Structure and Information Advantage: The Diversity–Bandwidth Tradeoff
Thursday 9 July
1230-1400
NAB room 4.21
We propose that a tradeoff between network diversity and communication channel bandwidth regulates the degree to which structurally diverse networks deliver non-redundant information, and thus higher performance for brokers. We argue that as the structural diversity of a network increases, the bandwidth of the communication channels in that network decrease, creating countervailing effects on the receipt of novel information. We base this argument on the observation that diverse networks are typically made up of weaker ties, characterized by narrower communication channels across which less diverse information is likely to flow. We further argue that this tradeoff is moderated by (a) the degree to which topics are uniformly or heterogeneously distributed over the alters in a broker’s network, b) the dimensionality of the information in a broker’s network (whether the total number of topics communicated by alters is large or small) and (c) the rate at which the information possessed by a broker’s contacts refreshes or changes over time. We test these arguments by combining social network and performance data with data on the information content flowing through email communication at a medium sized executive recruiting firm. These analyses unpack the mechanisms that enable information advantages in networks and serve as a ‘proof-of-concept’ for using email content data to analyze relationships among information, networks and the creation of social capital.
Sinan Aral is an Assistant Professor at the Information, Operations and Management Sciences department of the NYU Stern School of Business and affiliated faculty at MIT. He has won 4 best paper awards in ICIS (2 Overall and 2 in Track Themes) in 2006 and 2008, and the ACM SIGMIS Best Dissertation award in 2007. Sinan obtained his PhD in Information Systems from MIT and holds masters degrees from the London School of Economics (ADMIS), and Harvard University.
Sinan Aral's homepage
page last updated 13 July, 2009
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