The (Missing) Relation Between Acquisition Announcement Returns and Value Creation

Key Takeaways

• CAR fails to predict goodwill impairments, operating performance, or deal completion.
• Simple deal‑characteristics model predicts outcomes with 8‑11% five‑year return spread.
• Following CAR advice costs investors about ‑5% versus a 20% gain from characteristics.
• Most CAR‑based M&A wisdom on cash vs. stock deals is empirically wrong.
• Dollar‑scaled CAR correlates 6‑13× more with acquirer size than deal size.

Pulse Analysis

For decades, the cumulative abnormal return (CAR) has been the go‑to metric for measuring the market’s reaction to merger announcements. Scholars, practitioners and even courts have treated a positive CAR as a green light and a negative one as a red flag, embedding the measure into textbooks and litigation strategies. The new Journal of Finance study overturns this paradigm by showing that, across 47,000 deals spanning four decades, CAR bears essentially no relationship to the actual value created, as measured by goodwill impairments, post‑deal operating performance, or deal completion. The authors demonstrate that the stock price movement at announcement is driven largely by investors updating their view of the acquiring firm, not the specifics of the transaction.

A contrasting picture emerges when analysts use readily observable deal characteristics—such as relative size, payment method, target public status, acquirer leverage and past returns. Even a rudimentary model built on these variables predicts outcomes with meaningful accuracy, delivering an eight‑to‑eleven percent five‑year return spread between the best‑ and worst‑predicted deals. By comparison, CAR’s predictive spread barely exceeds three percent. This gap means that boards and compensation committees that base performance assessments on announcement‑period returns are likely rewarding noise rather than genuine deal‑making skill, while investors who follow CAR‑based advice can expect a five‑year loss of roughly five percent.

The implications ripple through multiple domains. Litigation and antitrust reviews that rely on event studies anchored to CAR risk drawing erroneous conclusions about value creation. Executive compensation tied to announcement returns may incentivize managers to chase market sentiment instead of sound strategic fit. Moreover, a substantial body of academic literature that has shaped conventional wisdom—such as the superiority of cash deals or the advantage of smaller acquirers—rests on a flawed signal. The study calls for the development and adoption of more robust, outcome‑oriented metrics that capture true acquisition performance, reshaping how scholars, regulators and corporate leaders evaluate M&A activity.