Poison Pills: Shareholder Rights Plans and Corporate Defense

Introduction

Financial and legal experts concur that one of the strongest antitakeover defense approaches is a shareholder rights strategy—or, in more informal terms, a poison pill. Though the particulars differ based on strategic implementation, the elementary defense tool offers existing shareholders (with the exception of hostile bidders) the right to purchase stocks that authorize them to obtain new shares at considerably low rates, should a hostile bidder acquire more than a specific percentage of the organization's outstanding shares. Consequently, poison pills accord the board of directors the ability to significantly dilute hostile bidders' ownership stakes, giving board members effective veto power to suppress hostile acquisition attempts. This paper addresses how accountants handle poison pills, including a summary of the poison pill concept, courts' responses to it, recent examples of poison pill adoption, and its effects on organizational value as well as its long-term influence on balance sheets and earnings.

Overview of the Poison Pill

Poison pills are a type of defense mechanism that target organizations employ to discourage hostile takeover attempts by acquirers. As the name suggests, a poison pill resembles something hard to tolerate or swallow—targeted organizations adopt such an approach to render their shares disadvantageous to acquirers. A poison pill drastically increases acquisition costs, creating large disincentives that may entirely deter such attempts. Such a tool helps safeguard minority shareholders while also preventing unwanted changes to organizational management or control. However, its implementation does not invariably signal that the organization is entirely opposed to acquisition; it may also be employed to obtain greater valuation or better acquisition terms.

The origins of the term "poison pill" may be traced back to the era of espionage and wartime, when undercover operatives carried poison pills on their person to swallow in the event of imminent capture. Likewise, target organizations adopt poison pill approaches to prevent hostile takeovers. The earliest usage of the term within the corporate finance domain is attributed to the United States. Such strategies have deliberate harmful effects for aggressive acquirers bent on taking over an organization.

With respect to acquisitions and mergers, the poison pill concept was first formulated in the early 1980s to prevent bidding organizations from negotiating share purchases directly with shareholders, instead coercing them to negotiate only with the board of directors. Poison pills are normally board-issued plans in warrant form or as an alternative connected to existing shares. No other entity within the organization but the board has the right to revoke them.

Organizations employ every means at hand to improve their market share, including acquisitions, mergers, and strategic alliances with fellow organizations in the same sector or market. Acquiring a rival firm is one way of eliminating or reducing competition. However, the management teams, founding members, and owners of target organizations generally prefer to maintain control over their company for multiple reasons—including the desire for more lucrative terms, emotional affinity, or greater valuation. They may therefore seek to quash acquisition offers from rival organizations. In the absence of a favorable response from the target organization's managers, rival firms wishing to acquire the organization might resort to directly approaching shareholders or striving for management replacement to gain approval for the acquisition. These tactics are considered hostile takeover attempts. Because shareholders—who are, in effect, company owners—are entitled to vote in favor of acquisition, a target organization's management team may employ a shareholder rights plan: a structural organizational development plan with particular conditions integrated into it for the specific purpose of foiling takeover attempts.

The firm known for the earliest application of this approach is Wachtell, Lipton, Rosen & Katz. Co-founder Martin Lipton devised this defense approach during a 1980s takeover battle in which his client, General American Oil, was targeted by T. Boone Pickens. Lipton recommended reducing corporate share value by creating an excess of new shares, thereby diluting Pickens' coveted ownership stake and dissuading the unwanted acquirer.

Ever since Lipton's implementation of this approach, numerous variants have been formulated, all incorporating the common idea of deterring external hostile takeover efforts by making the organization less attractive to acquirers or by increasing the power of existing shareholders. Both objectives may be achieved by selling inexpensive shares to existing shareholders, thus diluting the equity a hostile acquirer is likely to receive while simultaneously increasing equity for existing shareholders.

The Flip-In Provision

This type of approach entails enabling all shareholders, with the exception of the acquirer, to purchase additional discounted shares. While regular investors buy additional shares to gain instant profits, this simultaneously dilutes the value of the acquirer's shares. Such purchase rights are granted to shareholders prior to finalization of the takeover and are commonly triggered after an acquirer accumulates a specific threshold percentage of the target organization's shares. To illustrate, consider a poison pill activated after an acquirer purchases 30% of corporate shares. Upon implementation, all shareholders except the hostile acquirer are allowed to purchase new discounted shares. As the volume of additionally purchased shares increases, the hostile acquirer's interest becomes increasingly diluted and the bid cost rises. With new shares flooding the market, the acquirer's proportional share value decreases, rendering the takeover effort costlier and more challenging. Bidders who are aware of the possibility of such an approach may be disinclined to attempt a takeover in the first place. Flip-in provisions are typically disclosed openly in corporate charters and bylaws, indicating their potential use as a defense against takeovers.

The Flip-Over Poison Pill

A flip-over poison pill offers target organizations' stockholders the right to purchase the acquirer's shares at steep discounts in the event of a successful hostile takeover. For instance, a shareholder of a target organization might be entitled to purchase the acquirer's stock on a two-for-one basis, thereby diluting the acquiring organization's equity. The acquirer may choose not to proceed with this type of acquisition if it anticipates the dilution of its own value following the transaction.

Response to the Poison Pill by the Courts

The legitimacy of poison pills was ambiguous when the concept first emerged in the early 1980s. While the Supreme Court of Delaware supported the approach as a lawful defense mechanism in its 1985 ruling in Moran v. Household International, Inc., jurisdictions outside the United States have at times held the policy to be unlawful and have restricted its application. The majority of financial and legal experts claim that the pill's legal status outside Delaware was unclear until individual states implemented poison pill statutes legalizing its use. Such statutes fall under the broader class of antitakeover regulations passed by several states during the takeover era. The main types of antitakeover regulations include business combination acts, fair price acts, control share acquisition acts, and corporate constituency or directors' duties acts.

The argument typically offered regarding the pill's ambiguous standing outside Delaware prior to the ratification of poison pill statutes is that state courts' rulings nullified its application in the following states between 1986 and 1989: New York, Georgia, New Jersey, Indiana, Wisconsin, Colorado, and Virginia. However, the doubts raised by such decisions proved temporary, as all of these states enacted their own poison pill statutes shortly after the relevant nullifying court ruling. For instance, although the pill's usage was invalidated by the Supreme Court of New York in June 1988 in Bank of New York Co. v. Irving Bank Corp., New York State enacted a poison pill statute just six months later.

Furthermore, between 1986 and 1990, state court rulings in Maryland, Maine, Minnesota, Michigan, Wisconsin, and Texas supported the upholding—rather than the refutation—of the pill's legitimacy under those states' laws. This evidence suggests that the pill's validity was probably well established prior to these decisions; moreover, the pill definitively acquired legal validity in those states following acceptance via state court ruling.

Nevertheless, given that Delaware's common law influences the corporate regulations of every other state, later Delaware rulings—that is, rulings issued after the Moran case—may have had a greater bearing on the pill's legal ambiguity in other states than the earlier rulings of those states' own courts. In particular, in the autumn of 1988, Delaware's courts issued two notable decisions—Grand Metropolitan PLC v. Pillsbury Co. (November 1, 1988) and City Capital Associates v. Interco Inc. (November 1, 1988)—that introduced significant uncertainty regarding the poison pill's utilization, primarily affecting the pill's redemption rather than its validity per se. In both rulings, Delaware's court halted the continued application of active poison pills that were preventing unwanted tender offers. This generated considerable commentary, even inducing lawyers to advise clients to reincorporate outside Delaware. This development offers a plausible explanation for why a number of states adopted poison pill statutes between 1988 and 1990, since the pill's viability as a sound defense was no longer guaranteed following Pillsbury and Interco.

The Delaware Court's 1990 ruling in Paramount Communications, Inc. v. Time Inc. reversed the earlier Pillsbury and Interco decisions; some analysts argue that this ruling bestowed board members with broad authority to simply decline unwanted tender offers. However, numerous commentators maintain that Delaware's jurisprudence on pill redemption continues to be unsettled, typically dependent on fact-specific situations with limited general applicability. Because Delaware never enacted a formal poison pill statute, its position on the poison pill remains unique. In other states, following the conclusion of the first poison pill statute wave in 1990, the categorization of anti- and pro-pill states effectively came to an end; no further poison pill statute was enacted until 1995, when the second wave commenced.

Conclusion

A poison pill approach is a controversial tool. Nonetheless, researchers provide substantial evidence supporting the shareholder wealth maximization theory. Poison pills positively affect shareholder value, as compelling abnormal returns are exhibited by the market model. This finding holds for the CRSP Equally Weighted Index, the S&P 500, and the CRSP Value Weighted Index used as market benchmark alternatives. Moreover, the Fama-French momentum factor model confirms that the results are robust and not driven by model selection. Controlling for different sub-periods yields the insight that prevailing economic conditions influence stock price responses; however, positive market response to the adoption of poison pills remains robust across all time frames studied. Additional analyses suggest a weaker market response in cases of routine plan adoption, while the threat of a hostile takeover produces substantially larger abnormal returns. Interestingly, this effect is observed even when organizations have recently entered into friendly agreements. Although shareholders do not necessarily attach great importance to insulation from external market forces for corporate control, they appear to react favorably when opposing a hostile takeover attempt.

Overall, early research findings revealed a negative market response to the adoption of poison pills, while more recent studies reveal a trend toward positive market response. Considering the full body of evidence, it may be concluded that positive abnormal market returns associated with poison pill adoption exist; accordingly, the shareholder wealth maximization theory is supported, and poison pills appear to positively impact shareholder value.