Social Comparisons and Contributions to Online Communities: A Field Experiment on MovieLens

By D. Bobrow, Jack Whalen, Daniel Hughes, G. Coulson, J. Walkerdine, John O. Ledyard. Computational Social Systems and the Internet, 2010

532 citations recorded by the source corpus.

We explore the use of social comparison theory as a natural mechanism to increase contributions to an online movie recommendation community by investigating the effects of social information on user behavior in an online field experiment. We find that, after receiving behavioral information about the median user's total number of movie ratings, users below the median demonstrate a 530% increase in the number of monthly movie ratings, while those above the median decrease their monthly ratings by 62%. Movements from both ends converge towards the median, indicating conformity towards a newly-established social norm in a community where such a norm had been absent. Furthermore, the social information has a more dramatic effect on those below the median, suggesting an interaction between conformity and competitive preferences. When given outcome information about the average user's net benefit score from the system, consistent with social preference theory, users with net benefit scores above average contribute 94% of the new updates in the database. In both treatments, we find a highly significant Red Queen Effect.

Subfields: Management Science and Operations Research, Safety Research, Sociology and Political Science

View Paper: https://www.semanticscholar.org/paper/8aef5d833342dcfb193396cb7a544798f40797b0

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Citations in the corpus

A Review and Framework for Thinking about the Drivers of Prosocial Consumer Behavior (2020, background): “Descriptive norms have been shown to predict charitable giving (Frey and Meier 2004; Shang, Reed, and Croson 2008; Schrift and Amar 2015), increase volunteering (Chen et al. 2010), and facilitate other prosocial behaviors such as energy conservation (Goldstein, Cialdini, and Griskevicius 2008).”
Engineering Information Disclosure: Norm Shaping Designs (2016, background): “[18, 30]) demonstrated that showing a user what others are doing (or think should be done), leads to conformity in action (or with respect to normative expectations).”
Under-Savers Anonymous: Evidence on Self-Help Groups and Peer Pressure as a Savings Commitment Device (2012, background): “, 2012; Allcott, 2011) or contributions to public goods (e.g., Frey and Meier, 2004; Chen et al., 2010; DellaVigna et al., 2012), peer information has been shown to reduce work effort (Barankay, 2010) or lower take-up of tax credits (Manoli and Bhargava, 2011).”
"Popularity Effect" in User-Generated Content: Evidence from Online Product Reviews (2014, background): “Chen et al. (2010) show that by providing the median number of reviews contributed by community members, those who used to write less than the median write more.”
Designing Information Provision Experiments (2020, background): “Chen et al. (2010) find that personalized social information can significantly increase digital public goods provision, in the form of user moving ratings and community database maintenance.”
Employee Recognition and Performance: A Field Experiment (2016, background): “…a preference for conformity (for example, if they want to behave like others or to adhere to a group norm as in Bernheim, 1994, Sliwka, 2007, Fischer and Huddart, 2008, and Chen et al., 2010), this coarse rank information should increase effort of non-recipients and decrease effort of recipients.”
What We Know and Don't Know about Online Word-of-Mouth: A Review and Synthesis of the Literature (2014, background): “In addition, Chen et al. (2010) conducted a field experiment involving members of movielens.org, a movie recommendation website.”
Normative influences on thoughtful online participation (2011, background): “Online contributions can be motivated, for example, by the individual’s perception of their level of participation relative to others [4] or their degree of identification with a social group [33].”
Stimulating Online Reviews by Combining Financial Incentives and Social Norms (2017, unknown): “Chen et al. (2010) conducted an experiment on a movie reviewing website, MovieLens , wherein they inform a random set of subjects via email about the median number of reviews recently authored by their peers.”
Contagion of pro- and anti-social behavior among peers and the role of social proximity (2019, result): “This reasoning is coherent with findings on the asymmetry between positive and negative reciprocity (Offerman, 2002), the increase and decrease of pro-social behavior in contributing to a public good (Croson and Shang, 2008; Chen et al., 2010) and the findings on slippery-slope effects (Gino and Baz”
Saving more in groups: Field experimental evidence from Chile (2018, background): “, 2012) or contributions to public goods (e.g., Frey and Meier, 2004; Chen et al., 2010; DellaVigna et al., 2012), peer information has been shown to reduce work effort (Barankay, 2010) or lower take-up of tax credits (Manoli and Bhargava, 2011).”