User-generated Content and Social Media Harvard Business School

This paper documents what economists have learned about UGC and social media. A growing body of evidence suggests that UGC on platforms ranging from Yelp to Facebook has a large causal impact on economic and social outcomes ranging from restaurant decisions to voting behavior. These findings often leverage unique data sets and methods ranging from regression discontinuity to field experiments, and researchers often work directly with the companies they study. I then survey the factors that influence the quality of UGC. Quality is influenced by factors including promotional content, peer effects between contributors, biases of contributors, and self-selection into the decision to contribute. Nonpecuniary incentives, such as “badges” and social status on a platform, are often used to encourage and steer contributions. I then discuss other issues including business models, network effects, and privacy. Throughout the paper, I discuss open questions in this area. keywords: user-generated content, social media, economics of information, design economics JEL Codes: D8, L1, L86 1 I am grateful to the Editors, as well as Duncan Gilchrist, Shane Greenstein, and Scott Kominers for helpful comments. Janet Lu and Patrick Rooney provided excellent research assistance. 2 Harvard Business School