Research

Working Papers

• Finance

"Competing Effects of Income Inequality on Corporate Innovation: Incentive and Deprivation"

This study examines the effect of state income inequality on corporate innovation, focusing on its psychological dimensions. Income inequality is characterized by monetary incentives and relative deprivation. I investigate how these two characteristics of income inequality influence employee motivations, which in turn affects innovation quantity and quality. While monetary incentives boost innovation quantity, relative deprivation primarily hampers innovation quality. However, even when relative deprivation among employees remains low, income inequality can still positively impact both innovation quantity and quality. Policies aimed at reducing deprivation can enhance corporate innovation and contribute to social sustainability.

"Innovation Centrality, Profitability, and Stock Return" (co-authored with S. Ghon Rhee and Qianqiu Liu)

We study how a firm’s position in the corporate patent citation network relates to its profitability and future stock returns. From U.S. patent citations over 1976–2024, we build a dynamic, directed firm-level network and construct two measures: innovation centrality, defined as a firm’s weighted PageRank, and innovation centrality efficiency, centrality scaled by R&D expenditure. Highly central firms are more profitable but generate lower-quality innovation; centrality-efficient firms are also more profitable and earn lower future stock returns. Through the lens of industrial organization theory, a concentrated network position acts as a firm-level barrier to entry that lowers market and default risk, and central firms tend to hold the general-purpose technologies (GPTs) on which other firms depend. Peripheral firms developing the next GPTs are riskier and earn higher returns. This negative relation is stronger among firms with lower self-citation, lower technological diversity, and greater within-industry technological homophily.

"Income Inequality, Political Uncertainty, and Corporate Innovation"

This paper examines the effect of state income inequality on the relationship between political uncertainty and corporate innovation activities. In states with high income inequality, political uncertainty hinders corporate innovation, and political sentiment also significantly impacts innovation activities. However, in states with low income inequality, these political factors have little impact on corporate innovation. The effects of welfare expenditure and political alignment with the progressive party are mainly found in states with high income inequality. The results suggest that the high level of income inequality causes political unrest, which significantly impacts political factors on corporate innovation in states with high income inequality.

"Examination of the Ex-dividend Price Behavior of the Korean Stock Market" (co-authored with Dong Hyun Kim and Won Yong Kim)

This paper examines the ex-dividend stock price behavior of the Korean stock market, which has similar characteristics to the Japanese stock market. Selling pressure before the ex-dividend day and buying pressure on and after the ex-dividend day in the Korean stock market as in the Japanese stock market suggest that an institutional feature plays the greatest role in determining the stock prices on the ex-dividend day. I find that no existing theories explain the ex-dividend stock price behavior in Korea. Investors in the Korean stock market value the dividend lower than those in other stock markets because of its distinctive institutional features.

• Machine Learning / Data Analytics

"Consumer-grade or Clinical-grade? A Cost-Sensitive Framework for Biometric Authentication Technology Selection Hardware in Digital Finance" (co-authored with Sukhwa Hong and Gi-Chul Yang), under review.

Authentication failure in mobile financial services creates asymmetric operational costs: false acceptance raises fraud exposure, whereas false rejection creates customer friction. Conventional biometric metrics do not translate these errors into organizational consequences or guide hardware investment. We develop a design-science method combining a five-parameter frequency-severity model, leakage-avoiding evaluation, and a total-cost-of-ownership rule. Sixteen EEG architectures are evaluated on a three-subject consumer-grade pilot and a 106-subject clinical benchmark across five channel counts. Cross-run evaluation materially lowers reported performance, and the pilot ranking does not replicate: Wavelet-CNN EER rises from 1.46% to 19.13% at Fp1, whereas CNN-BiLSTM has the strongest large-sample single-channel result (11.00%) and remains robust across channels. Using this large-sample anchor, the model identifies bounded combinations of exposure, authentication frequency, attack prevalence, and rejection friction for which a low-cost single-channel configuration has lower total cost. Substituting the pilot estimate moves the moderate-use break-even by more than an order of magnitude. The findings show that evaluation validity is economically consequential and provide a transparent rule for risk-tiered authentication and technology procurement.

"Effectively Delivering Author’s Point to Reader: Pointer-Generator Network Approach" (co-authored with Sukhwa Hong)

We propose a communication-based text summarization approach utilizing a pointer-generator network. The proposed summarization algorithm combines elements of abstractive summarization with keyword extraction. These keywords are associated with threats, causality, evidence, and solutions, all aimed at influencing readers' behavior. This paper is grounded in the theoretical frameworks of Language-Action Perspective (LAP) and Speech Act Theory (SAT), which are applied within the context of social and behavior change communication (SBCC). Consequently, our ultimate model considers the target readers to enhance the effectiveness of communication for promoting social and behavioral change. The SBCC-based summary incorporates more persuasive and emotive language while prioritizing SBCC-related content from the original article. This study demonstrates the potential effectiveness of a summary that encapsulates the author's intentions in shaping readers' thoughts and behaviors.

Work In Progress

"ESG Policy and Corporate Innovation" (co-authored with Jing Ai and Tianyang Wang)

“Firms' Intention to Innovate and Asset Prices: Pointer-Generator Network Approach” (co-authored with Sukhwa Hong)