Unocal at 20: Director Primacy in Corporate Takeovers

100 Pages Posted: 7 Sep 2005

See all articles by Stephen M. Bainbridge

Stephen M. Bainbridge

University of California, Los Angeles (UCLA) - School of Law

Multiple version iconThere are 2 versions of this paper

Date Written: September 2005


In Unocal Corp. v. Mesa Petroleum Co., the Delaware Supreme Court made clear that the board of directors of a target corporation "is not a passive instrumentality" in the face of an unsolicited tender offer or other takeover bid. To the contrary, so long as the target board's actions are neither coercive nor preclusive, the target's board remains "the defender of the metaphorical medieval corporate bastion and the protector of the corporation's shareholders."

Unocal is almost universally condemned in the academic corporate law literature. Building on his director primacy model of corporate governance and law, however, Bainbridge offers a defense of Unocal in this article. Bainbridge argues that Unocal strikes an appropriate balance between two competing but equally legitimate goals of corporate law: On the one hand, because the power to review differs only in degree and not in kind from the power to decide, the discretionary authority of the board of directors must be insulated from shareholder and judicial oversight in order to promote efficient corporate decision making. On the other hand, because directors are obligated to maximize shareholder wealth, there must mechanisms to ensure director accountability. The Unocal framework provides courts with a mechanism for filtering out those cases in which directors have abused their authority from those in which directors have not.

Keywords: corporate governance, takeovers, tender offers

JEL Classification: K22

Suggested Citation

Bainbridge, Stephen Mark, Unocal at 20: Director Primacy in Corporate Takeovers (September 2005). UCLA School of Law, Law-Econ Research Paper No. 05-19. Available at SSRN: or

Stephen Mark Bainbridge (Contact Author)

University of California, Los Angeles (UCLA) - School of Law ( email )

385 Charles E. Young Dr. East
Room 1242
Los Angeles, CA 90095-1476
United States
310-206-1599 (Phone)
310-825-6023 (Fax)


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