Doctoral Student

Aaron Yoon

Aaron S. Yoon is a doctoral student in the Accounting & Management Unit at Harvard Business School. His research interests are in the capital markets, valuation, and corporate governance.

Aaron earned his M.A. and B.A. in Economics along with a B.A. in Mathematical Methods in the Social Sciences in four years with honors from Northwestern University. Prior to his doctoral studies, Aaron was an equity trader and a quantitative research analyst at Credit Suisse. He also controlled air traffic in the Eighth Army for two years.

Working Papers

  1. Corporate Sustainability: First Evidence on Materiality

    Mozaffar Khan, George Serafeim and Aaron Yoon

    An increasing number of companies make sustainability investments, and an increasing number of investors integrate sustainability performance data in their capital allocation decisions. To date however, the prior academic literature has not distinguished between investments in material versus immaterial sustainability issues. We develop a novel dataset by hand-mapping data on sustainability investments classified as material for each industry into firm-specific performance data on a variety of sustainability investments. This allows us to present new evidence on the value implications of sustainability investments. Using calendar-time portfolio stock return regressions we find that firms with good performance on material sustainability issues significantly outperform firms with poor performance on these issues, suggesting that investments in sustainability issues are shareholder-value enhancing. Further, firms with good performance on sustainability issues not classified as material do not underperform firms with poor performance on these same issues, suggesting investments in sustainability issues are at a minimum not value-destroying. Finally, firms with good performance on material issues and concurrently poor performance on immaterial issues perform the best. These results speak to the efficiency of firms' sustainability investments, and also have implications for asset managers who have committed to the integration of sustainability factors in their capital allocation decisions.

    Keywords: sustainability; corporate sustainability; corporate social responsibility; investment; investment management; investment return; investment strategy; Investments; Corporate performance; Corporate Social Responsibility and Impact; Performance; Investment; Environmental Sustainability;

    Citation:

    Khan, Mozaffar, George Serafeim, and Aaron Yoon. "Corporate Sustainability: First Evidence on Materiality." Harvard Business School Working Paper, No. 15-073, March 2015. View Details