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. 2015 Sep 2;10(9):e0136327.
doi: 10.1371/journal.pone.0136327. eCollection 2015.

Editorial Bias in Crowd-Sourced Political Information

Free PMC article

Editorial Bias in Crowd-Sourced Political Information

Joshua L Kalla et al. PLoS One. .
Free PMC article


The Internet has dramatically expanded citizens' access to and ability to engage with political information. On many websites, any user can contribute and edit "crowd-sourced" information about important political figures. One of the most prominent examples of crowd-sourced information on the Internet is Wikipedia, a free and open encyclopedia created and edited entirely by users, and one of the world's most accessed websites. While previous studies of crowd-sourced information platforms have found them to be accurate, few have considered biases in what kinds of information are included. We report the results of four randomized field experiments that sought to explore what biases exist in the political articles of this collaborative website. By randomly assigning factually true but either positive or negative and cited or uncited information to the Wikipedia pages of U.S. senators, we uncover substantial evidence of an editorial bias toward positivity on Wikipedia: Negative facts are 36% more likely to be removed by Wikipedia editors than positive facts within 12 hours and 29% more likely within 3 days. Although citations substantially increase an edit's survival time, the editorial bias toward positivity is not eliminated by inclusion of a citation. We replicate this study on the Wikipedia pages of deceased as well as recently retired but living senators and find no evidence of an editorial bias in either. Our results demonstrate that crowd-sourced information is subject to an editorial bias that favors the politically active.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.


Fig 1
Fig 1. Kaplan-Meier survival curves across all studies and all conditions.
Studies 1, 2, and 4 were conducted on the current U.S. senators while Study 3 was conducted using the Wikipedia pages of retired and deceased senators. Results show that among active senators, negative facts are fare more likely to be removed more quickly than positive facts.

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