SK Award-Winning Scholar Interview – Professor Minjae Koo

In 2025, Professor Minjae Koo of Korea University Business School received the SK·IBRE Award for his co-authored paper, “Riding Attention Spikes: How Analysts Respond to Advertising” (co-authors: Annika Wang, Yin Wang, and Liandong Zhang), which has been accepted for publication in Contemporary Accounting Research. This study investigates how sell-side analysts strategically respond to spikes in investor attention caused by corporate advertising. The paper has been highly regarded in academia for demonstrating how the interplay between advertising and optimistic analyst forecasts significantly increases retail investor trading activity.

Q1. First of all, congratulations on winning the SK Award. Could you share your thoughts on receiving this honor?

A1. Thank you very much. I am deeply honored to receive the SK·IBRE Award. This recognition is both humbling and encouraging. I view it as a meaningful milestone in my academic journey and a strong motivation to further explore topics related to market inefficiencies. I will continue striving to broaden the scope of accounting research and contribute to the field in meaningful ways.

Q2. Could you briefly introduce the research (paper/finding) that earned you this award?

A2. Certainly. This paper examines how sell-side financial analysts respond to spikes in investor attention induced by product advertising. Our findings suggest that analysts issue more optimistic earnings forecasts following weeks with intensified advertising activity. This tendency is especially pronounced when analysts are affiliated with brokerages that benefit from increased trading commissions. These strategic forecast revisions amplify the trading activity of retail investors, highlighting how non-informational events such as advertising can shape capital market outcomes.

Q3. Could you share what motivated you to start this research or the background behind it?

A3. The idea originated from emerging evidence that, although advertising provides limited fundamental information, it draws substantial investor attention and increases retail trading volume. We became interested in whether financial analysts—who serve as key information intermediaries in capital markets—might actively leverage these attention spikes. Given their economic incentives to stimulate trading, we hypothesized that analysts would strategically issue more optimistic forecasts when investor attention is elevated.

Q4. How do you think your research outcomes could impact society or the industry?

A4. This study underscores a previously underexplored dimension of market inefficiency: the strategic behavior of financial analysts in response to non-informational stimuli like advertising. These findings carry important implications for investor protection and market transparency. They also offer insights for policymakers and regulators aiming to understand how advertising may influence financial decision-making and the dynamics of investor behavior in capital markets.

Q5. Could you share your future research plans or specific topics of interest?

A5. I’m currently interested in the growing role of non-traditional information intermediaries—such as social media influencers—in shaping investor sentiment and firm valuation. The rise of digital platforms like mobile trading apps and social networks has fundamentally changed the way market participants access and interact with financial information. I hope to explore how these new communication channels affect corporate behavior, investor perception, and overall market efficiency.

Q6. If there’s a message you’d like to share with students, please feel free to do so.

A6. Stay curious and never shy away from challenging conventional wisdom. Cultivate a mindset that remains open to diverse sources of information—whether from YouTube, books, news, or magazines. Some of the most profound insights often emerge from bridging ideas across seemingly unrelated fields. Keep thinking critically, remain open-minded, and persevere in your intellectual pursuits.

Summary of Professor Minjae Koo’s Paper

「Riding Attention Spikes: How Analysts Respond to Advertising」

This study investigates how sell-side analysts strategically respond to increases in investor attention caused by product advertising. Using weekly advertising data, we find that analysts tend to issue more optimistic earnings forecasts in the weeks following heightened advertising activity, particularly when they are affiliated with brokerages that derive significant revenue from trading commissions. This behavior is more prominent among experienced analysts and those serving a retail investor clientele, suggesting a strategic—rather than cognitive—bias. The combination of advertising-induced attention and optimistic analyst forecasts significantly boosts retail trading volume, illustrating how non-informational stimuli can interact with market intermediaries to amplify financial market reactions. The findings highlight analysts' potential role in distorting information flow and underscore important considerations for market efficiency and investor protection.