A Little Bit Goes a Long Way: Indirect Effects of Content Moderation on Online Social Media
研究利用Reddit的自然实验，发现禁止篡改新闻标题的政策不仅直接降低了标题的负面情绪，还通过社会传染间接减少了其他用户帖子的负面情绪，且未损害用户参与度。
This article investigates the unintended indirect effects of a content moderation policy change on Reddit. Leveraging a natural experiment, the study examines a subreddit rule that prohibits altering the headlines of news articles shared on the platform. While the policy aimed to prevent misinformation, it unexpectedly reduced negative sentiment and emotion in user posts. The analysis reveals that the rule directly lowered negativity in shared news headlines and indirectly reduced negativity in other user-generated content over time, despite this content not being directly targeted. This indirect effect is attributed to social contagion, where reduced negativity in news headlines propagated to user posts. Beyond content characteristics, the policy change influenced user engagement. An initial drop in posting was followed by increased engagement with nontargeted content, highlighting unintended behavioral effects. The findings suggest that content moderation policies, although reducing negativity, may avoid long-term harm to user engagement. This study underscores the need for a nuanced understanding of the broader implications of moderation policies for social media platforms, users, and regulators. Additionally, it provides empirical evidence for the presence of social contagion in online social media.