Open-Loop Equilibria and Perfect Competition in Option Exercise Games
指出Grenadier（2002）定义的寡头投资博弈均衡仅适用于开环策略；在闭环策略下，企业可通过提前投资抢占增长期权，而完全竞争结果由闭环策略的相互最优反应产生，此时延迟期权价值为零，所有企业遵循简单净现值规则。
The investment boundaries defined by Grenadier (2002) for an oligopoly investment game determine equilibria in open-loop strategies. As closed-loop strategies, they are not equilibria, because any firm by investing sooner can preempt the investments of other firms and expropriate the growth options. The perfectly competitive outcome is produced by closed-loop strategies that are mutually best responses. In this equilibrium, the option to delay investment has zero value, and the simple NPV rule is followed by all firms. The Author 2009. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org., Oxford University Press.