Contact Info

Rick Wash
404 Wilson Rd #402
402 Communication Arts and Sciences
Michigan State University
East Lansing, MI 48824

Cell: (734) 730-1188
Office: (517) 355-2381

Using a Minimum Threshold to Motivate Contributions to Social Computing

by: Rick Wash and Jeff MacKie-Mason


Social computing systems collect, aggregate, and share user-contributed content, and therefore depend on contributions from users to function properly. However, humans are intelligent beings and cannot be programmed to behave; system designers must provide incentives to encourage users to contribute. We explore the behavioral consequences of one simple incentive mechanism: require users to contribute a minimum amount of information before they are granted access to the system. Users with a high marginal cost of contribution will stop using the system, but users with a moderate marginal cost will increase their contribution, frequently leading to greater benefits for everyone still using the system. Additionally, if contributions are collaborative and build upon each other, then existing contributors are likely to slightly decrease their contributions, leading to a more ‘equal’ distribution of contributions. We show that this mechanism often leads to increased contributions, and provide concrete design advice for using this mechanism in social computing systems.


Rick Wash and Jeff MacKie-Mason. “Using a Minimum Threshold to Motivate Contributions to Social ComputingWorking paper. June 2009.

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