Poison or placebo? Evidence on the deterrence and wealth effects of modern antitakeover measures
用大样本证据表明，毒丸计划、控制权股份法和企业合并法并未系统性地阻止收购，反而提高了出售股东的收购溢价，增强了目标公司的谈判地位，但并未阻止多数交易。
This paper provides large-sample evidence that poison pill rights issues, control share laws, and business combination laws have not systematically deterred takeovers and are unlikely to have caused the demise of the 1980s market for corporate control, even though 87% of all exchange-listed firms are now covered by one of these antitakeover measures. We show that poison pills and control share laws are reliably associated with higher takeover premiums for selling shareholders, both unconditionally and conditional on a successful takeover, and we provide updated event study evidence for the three-quarters of all poison pills not yet analyzed. Antitakeover measures increase the bargaining position of target firms, but they do not prevent many transactions.