Publications & Working Papers
2025
Systematic AI Privacy Violations Under Economic Incentives
Kai Li, Yifu Liu, Yifei Zhang, Yiran Zhang
Working Paper New Working Paper
We investigate how economic incentives drive systematic AI privacy violations, analyzing how data-intensive AI deployment shapes firm-level privacy risks, strategic compliance, and governance outcomes.
Corporate Venture Capital and Firm Scope
Yifei Zhang
Published in Journal of Financial and Quantitative Analysis (JFQA), Vol. 60, No. 1, Feb. 2025, pp. 336–373. Published Solo Paper
This study examines whether and how corporate venture capital (CVC) spurs changes in firm scope. Using two text-based measures of firm scope, I provide evidence that CVC investments are strongly correlated with subsequent changes in firm scope among CVC parent firms, including seeding emerging businesses and creating new segments or divisions. Further evidence is consistent with an experimentation view, with more promising ventures having a stronger strategic impact on the scope changes of parent firms. Moreover, the study finds that post-CVC scope changes are primarily built internally and rarely involve killer acquisitions. These changes create value for CVC parents.
Climate Innovation and Carbon Emissions: Evidence from Supply Chain Networks
Ulrich Hege, Kai Li, Yifei Zhang
Working Paper (WFA 2024, EFA 2024, FIRS 2025) WFA Wharton-WRDS Best Empirical Finance Paper Award Paris December Meeting Best Paper Award
We study the effect of climate-related innovation on carbon emissions by analyzing supply chain networks. We find that climate innovation reduces carbon emissions at customer firms, driven by product innovations. The effect is economically significant, dominated by the most emission-intensive customer firms, gradually increases over a five-year horizon, and is significant for Scope 1 and Scope 2 emissions. Customers exhibit a strong preference for suppliers with new climate patents, and these new customers subsequently reduce their emissions.
2024
Climate Patents and Financial Markets
Ulrich Hege, Sébastien Pouget, Yifei Zhang
Working Paper (2nd Round Minor Revision JFQA) 2nd Round Minor Revision JFQA
We study the financial markets reaction to climate patents announcements. Exploiting quasi-random variations in patent examiner leniency to allow for causal interpretations, we find that firms with fortuitous climate patent grants benefit from positive medium-run abnormal stock returns and a lower cost of capital compared to similarly innovative but unlucky firms.
Incident-Driven Green Products
Yifei Zhang
Working Paper (Revise & Resubmit JFQA) Revise & Resubmit JFQA Solo Paper
We employ the ChatGPT model to identify green products in the US product markets. Approximately 3.7% of US product announcements from 2002 to 2022 qualify as green products. Using a stacked Difference-in-Differences approach, we find that firms involved in severe environmental incidents launch 40% more green products within two years following the incidents. These incident-driven green products are notably novel, supported by high-quality green patents, and result in substantial environmental improvements for both producers and consumers.
2019
Activism Pressure and The Market for Corporate Assets
Ulrich Hege, Yifei Zhang
Working Paper (AFA 2020)
We examine how shareholder activism pressure shapes corporate asset restructuring and the liquidity and reallocation of assets in the market for corporate assets.