Law Commons^™

Power And Statistical Significance In Securities Fraud Litigation, Jill E. Fisch, Jonah B. Gelbach

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Event studies, a half-century-old approach to measuring the effect of events on stock prices, are now ubiquitous in securities fraud litigation. In determining whether the event study demonstrates a price effect, expert witnesses typically base their conclusion on whether the results are statistically significant at the 95% confidence level, a threshold that is drawn from the academic literature. As a positive matter, this represents a disconnect with legal standards of proof. As a normative matter, it may reduce enforcement of fraud claims because litigation event studies typically involve quite low statistical power even for large-scale frauds.

This paper, written for …

The Logic And Limits Of Event Studies In Securities Fraud Litigation, Jill E. Fisch, Jonah B. Gelbach, Jonathan Klick

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Event studies have become increasingly important in securities fraud litigation after the Supreme Court’s decision in Halliburton II. Litigants have used event study methodology, which empirically analyzes the relationship between the disclosure of corporate information and the issuer’s stock price, to provide evidence in the evaluation of key elements of federal securities fraud, including materiality, reliance, causation, and damages. As the use of event studies grows and they increasingly serve a gatekeeping function in determining whether litigation will proceed beyond a preliminary stage, it will be critical for courts to use them correctly.

This Article explores an array of …

Expert Mining And Required Disclosure, Jonah B. Gelbach

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No abstract provided.

Reconceptualizing Trespass, Gideon Parchomovsky, Alex Stein

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This Essay addresses an anomaly in trespass law. Trespass law is generally understood as the paradigmatic example of property-rule protection: an owner can obtain an injunction against the trespasser and have him removed from her land. The property-rule protection enjoyed by the owner protects her right to exclude others and to set the price for the use of her property. However, the property-rule protection only exists ex ante: it avails only against imminent or ongoing trespasses. Ex post, after a trespass ends, the owner can only recover compensation measured by the market value of the unauthorized use, i.e., the going …

Torts And Innovation, Gideon Parchomovsky, Alex Stein

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This Essay exposes and analyzes a hitherto overlooked cost of the current design of tort law: its adverse effect on innovation. Tort liability for negligence, defective products, and medical malpractice is determined by reference to custom. We demonstrate that courts’ reliance on custom and conventional technologies as the benchmark of liability chills innovation and distorts its path. Specifically, the recourse to custom taxes innovators and subsidizes replicators of conventional technologies. We explore the causes and consequences of this phenomenon and propose two possible ways to modify tort law in order to make it more welcoming to innovation.