A working paper version with detailed analysis and discussion is available here: ssrn.com/abstract=433....

The published version in Marketing Science can be accessed here: pubsonline.informs.org/doi/pdf/10.1...

Verified reviewers show no gender bias in their ratings relative to critics, while non-verified reviewers continue to disproportionately penalize female-led films.

This suggests that verification can serve as an effective safeguard against gender biases in crowd ratings.

In 2019, Rotten Tomatoes introduced one such measure: verified reviews, which can only be posted by users who can prove they watched the movie. So how does the gender gap compare between verified and non-verified crowd ratings? Does it persist among verified reviewers?

This is bad news, but what can be done? If this bias reflects the behavior of a few malicious reviewers rather than a general trend among the crowds, platforms could implement screening mechanisms to filter out these bad apples.

Notably, this higher share of extremely low ratings is exclusively driven by male crowd reviewers. When rated by the latter, female movies receive a share of extremely low ratings that is over 50% higher than that of male movies.

I also explore an alternative gender gap: the difference in the share of extremely low ratings (10 on a 10-100 scale) received by female and male movies. Female-led films again receive a much higher share of extremely low ratings when rated by crowds, but not by critics.

Using data on 12,657 movies, I focus on the "gender score gap": the difference in rating scores received by women-led and men-led movies. I find that while critics rate both movie types evenly, crowds consistently rate female-led movies lower, both on IMDb and on Rotten Tomatoes.

Remember the intense crowd-driven backlash and review bombing of female-led films like the 2016 Ghostbusters reboot and Captain Marvel, or TV-shows like Ms. Marvel and She-Hulk? These cases may seem isolated, but what if they point to a systemic bias against female-led films?

Consumers rely on both professional critics and crowds for movie ratings. But while critics have incentives to remain objective, crowd reviewers face no such accountability, enabling malicious reviewers to easily express their animosity on platforms like Rotten Tomatoes or IMDb.

🎬 Great news: Female leads in top-grossing films have recently hit historic highs!

But what if female-led movies face hidden bias in online ratings? In a recent study, I uncovered troubling gender bias on platforms like Rotten Tomatoes and IMDb... 🧵🍿