Why Does Corporate Governance Affect Firm Value: Evidence on a Self-Dealing Channel from a Natural Experiment in Korea

Prior work in emerging markets provides evidence that better corporate governance predicts higher market value, but very little on the specific channels through which governance increases value. We provide evidence, from a natural experiment in Korea, that reduced tunneling can be an important channel. Korean legal reform in 1999 improved board independence of “large” firms (assets > 2 trillion won) relative to smaller firms. This shock to governance allows us to assess the effects of reform using a regression discontinuity design. In event studies of the reform events, we show that large firms whose controllers have incentive to tunnel (positive Expropriation Risk Index firms) earn strong positive returns, relative to other large firms. In panel regressions over 1998-2004, we also show that better governance (higher Korea Corporate Governance Index) moderates the negative effect of related-party transactions on value and increases the sensitivity of firm profitability to industry profitability (consistent with less tunneling).

In a companion paper, Bernard Black and Woochan Kim, The Effect of Board Structure on Firm Value: A Multiple Identification Strategy Approach Using Korean Data (working paper 2008), http://ssrn.com/abstract=968287, we seek to identify Korean board structure reforms as likely causing an increase in firm market value.

For our earlier cross-sectional research on Korean corporate governance, see:

Bernard Black, Hasung Jang and Woochan Kim, Does Corporate Governance Affect Firms' Market Values? Evidence from Korea,: 22 Journal of Law, Economics and Organization 366-413 (2006), nearly final version at http://ssrn.com/abstract=311275.

Bernard Black, Hasung Jang & Woochan Kim, Predicting Firms' Corporate Governance Choices: Evidence from Korea, 12 Journal of Corporate Finance 660-691 (2006), nearly final version at http://ssrn.com/abstract=428662.