Kai Zhu
kai-zzzzzz.bsky.social
Kai Zhu
@kai-zzzzzz.bsky.social
Assistant Professor at Bocconi University

https://kaizhu.me/
The Mismatch: Why lower ratings? We used a fine-tuned BERT model to analyze review text. The results suggest an increase in consumer-book mismatches.

With reduced diversity (a shrinking "long tail"), readers were more likely to receive books misaligned with their preferences.
August 4, 2025 at 10:10 AM
The Demand Paradox: How did readers (demand side) respond? The promotional effects intensified, but with a paradox.

Books in the paid program received a HIGHER volume of reviews, but LOWER average ratings. Monetization amplified the "Groupon effect."
August 4, 2025 at 10:10 AM
The "Rich-Get-Richer" Dynamic: Diving deeper, we saw a "rich-get-richer" effect. Popular genres (like Mystery/Thriller) became more dominant, while niche genres (like Poetry/Science) lost market share. The entry cost narrowed the range of cultural products being promoted.
August 4, 2025 at 10:10 AM
The Diversity Drop: This shift in suppliers directly affected product variety. We measured a significant decline in the diversity of book genres available in the program post-monetization. The marketplace became less varied.
August 4, 2025 at 10:10 AM
Market Concentration & Author Profiles: This led to a massive 200% increase in market concentration (HHI). Furthermore, the authors who continued to participate post-monetization were generally more established, popular, and experienced with the platform.
August 4, 2025 at 10:10 AM
Uneven Impact & Concentration: Importantly, the impact was uneven. The cost disproportionately pushed out indie publishers and self-published authors.

While overall participation dropped, the market share of the "Big 5" publishing houses more than doubled (12% to 30%).
August 4, 2025 at 10:10 AM
The Supply Shock: The impact on the supply side was immediate and dramatic. Introducing the entry cost caused the average number of monthly promotional campaigns to plummet from ~3,000 to ~1,000.
August 4, 2025 at 10:10 AM
We studied the Goodreads "Giveaways" program, a marketplace for book promotion. It was free for authors/publishers until Jan 2018, when Goodreads introduced a fixed $119 entry cost.

This provided a natural experiment to study monetization in a two-sided market.
August 4, 2025 at 10:10 AM
📣 Thrilled to announce our new paper, "Monetizing Platforms: An Empirical Analysis of Supply and Demand Responses to Entry Costs in Two-Sided Markets," is now published in Management Science!

When a digital platform starts charging for access, who wins and who loses? 🧵👇
August 4, 2025 at 10:10 AM
Our analysis of content reveals mixed progress: biographical and geographical content are moving toward better representation, yet disparities persist.
February 24, 2025 at 6:03 PM
However, the benefits aren’t equally distributed. Languages with larger content bases and active communities see much larger gains in content creation compared to smaller editions.
February 24, 2025 at 6:03 PM
Reader engagement remains robust too. Translated articles show consistent pageviews, and combined source–target readership increases overall reach.
February 24, 2025 at 6:03 PM
On the quality front, despite the surge in translation volume, we observe lower deletion rates and a modest improvement in structural quality scores.
February 24, 2025 at 6:03 PM
Our findings are striking: content translation volume increased by 149% on average—demonstrating how AI lowers language barriers and significantly increase cross-language knowledge transfer.
February 24, 2025 at 6:03 PM
We leverage Wikipedia’s integration of Google Translate (Jan 2019) as a natural experiment. This integration provides editors with a more advanced technology (transformer-based MT) for translating content across languages.
February 24, 2025 at 6:03 PM
Excited to share our revised working paper on Machine-assisted Content Creation on Peer Production Platforms—we have made significant changes and additions!

Our study explores how AI-powered translation reshapes multilingual content creation on platforms like Wikipedia.
February 24, 2025 at 6:03 PM
I should be working on my paper revision, but I could not stop myself from pulling relevant data and creating this plot:

Elon Musk's Wokepedia attack seems to act as a surprisingly effective call for donations!
December 27, 2024 at 6:39 AM