Three Essays on Network Development, Social Influence, and User Engagement in Online Communities




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I study influential factors on users’ activities in online communities in three chapters. Using unique data coming from an online anime (Japanese cartoon) platform containing data on users’ friendship networks, anime adoptions, and generated content over time, I look into consumers’ decisions in the context of new media such as online streaming.

In the first chapter of this dissertation, I study the effects of observational learning and word-of-mouth (volume and valence) on consumers’ product adoptions. Understanding whether these two social learning devices provide different and unique information or whether one is redundant in the presence of the other is crucial for companies’ information provision strategies. I differentiate between the effects of word-of-mouth and observational learning from friends (“personal network”) and the effects of word-of-mouth and observational learning from the whole community (“community network”). The relative importance of word-of-mouth and observational learning at each network level provides guidance for companies’ platform design. My results reveal that both word-of-mouth and observational learning from both the community and personal networks have significant and positive effects on individual users adoption decisions. I find that word-of-mouth valence from the community network is the largest adoption driver among the social learning forces I study. Lastly, I test for asymmetric observational learning from positive and negative actions and observational learning creating product awareness versus transferring unobserved quality information.

In the second chapter, I quantify the effects of binge-watching on consumers’ engagement with media franchises in two areas: interactive and personal engagement. The former involves a user’s content generation related to a focal media product and the latter concerns the adoption of franchise extensions (sequels and other extensions). I find that binge-watching has a negative effect on the production of user-generated content. The effect of binge-watching on the adoption of franchise extensions critically depends on both the availability of franchise extensions at the time of watching the focal anime and the extension type: if it is available, binge-watching increases (decreases) the probability that a user watches the sequel (other franchise extensions).

In the third chapter, I develop a structural model for the co-evolution of individuals’ friendship tie formations and their concurrent online activities (product adoptions and production of user-generated content) within a social network. Explicitly modeling the endogenous formation of the network and accounting for the interdependence between decisions in these two areas (friendship formations and online activities) provides a clean identification of peer effects and of important drivers of individuals’ friendship decisions. My results reveal that, compared to a potential friend’s product adoptions and content generation activities, total number of friends and number of common friends this potential friend has with the focal individual are the most important drivers of friendship formation. Further, while having more friends does not make a person more active, having more active friends increases a user’s activity levels in terms of both product adoptions and content generation through peer effects. Via counterfactuals I assess the effectiveness of various seeding strategies in increasing website traffic while taking the endogenous network formation into account.



Online social networks, Peer pressure, Word-of-mouth advertising, Product management, User-generated content, Binge watching (Television), Franchises (Retail trade), Consumer behavior, Streaming video


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