Essays on Social Network Propagation, Online Privacy, and Security

• Author / Creator

  Hidaji, Hooman

• This thesis is composed of four essays addressing problems in the domain of information systems (IS). In the first essay, we study methods for improving propagation of messages in both consumer and enterprise social networks. We present the formal definition and analysis of the problem, and use the hop-constrained minimum spanning tree (HMST) model to find cost-effective seeds and possible new connections that result in networks with improved propagation properties. Moreover, we present new heuristic algorithms that substantially improve the solution quality for the HMST problem, as tested on both random and real-world networks. In the second essay, we study the decision making of publisher websites in using third parties. We propose a two-sided economic model that captures the interaction between users, publisher websites, and third parties. Specifically, we focus on the effect of user privacy concerns on information sharing behavior of publisher websites. We then analyze welfare aspects and provide insights on the impact of industry regulations on stakeholders. The model is validated using an exploratory empirical analysis of publisher websites’ third party sharing. Following this topic, in the third essay, we examine the impact of user privacy concerns as the self-regulatory mechanism that induces the website publisher to respect user privacy concerns. We conduct experiments designed to test the impact of users’ privacy concerns, and find that the privacy concerns do affect the sharing intensity of user information by the websites. We analyze the effectiveness of passive “Do Not Track” and active “AdBlock Plus” privacy tools in a self-regulated environment. Interestingly, we find that the “Do Not Track” request does not always serve its intended purpose, but is actually being used by many websites as a signal to substantially increase the user information sharing intensity. Finally, in the fourth essay, we examine a firm’s choice of information technology supplier, where customers’ demand changes in response to adverse events or incidents that occur at the firms. We specifically model the strategic choice of firms choosing between either a shared supplier versus an independent supplier. In a symmetric duopoly setting, we show that this choice depends on the customer demand reactions to adverse events as well as relative risks of the suppliers. We also analyze the effectiveness of regulation and cooperation in improving firms’ profit.

• Subjects / Keywords

  • Privacy
  • Supplier risk
  • Hop constrained minimum spanning tree
  • Economics of information systems
  • Network alteration
  • Social network propagation
  • Supply chains
  • Third parties
  • Direct- and cross-risk elasticities of demand

• Graduation date

  Spring 2017

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3JQ0T691

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.