Social and Behavioral Sciences Commons^™

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

All Faculty Scholarship

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

All Faculty Scholarship

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 …

Actions Speak Louder Than Images: The Use Of Neuroscientific Evidence In Criminal Cases, Stephen J. Morse

All Faculty Scholarship

This invited commentary for Journal of Law & the Biosciences considers four empirical studies previously published in the journal of the reception of neuroscientific evidence in criminal cases in the United States, Canada, England and Wales, and the Netherlands. There are conceded methodological problems with all, but the data are nonetheless instructive and suggestive. The thesis of the comment is that the courts are committing the same errors that have bedeviled the reception of psychiatric and psychological evidence. There is insufficient caution about the state of the science, and more importantly, there is insufficient understanding of the relevance of the …

Catalogs, Gideon Parchomovsky, Alex Stein

All Faculty Scholarship

It is a virtual axiom in the world of law that legal norms come in two prototypes: rules and standards. The accepted lore suggests that rules should be formulated to regulate recurrent and frequent behaviors, whose contours can be defined with sufficient precision. Standards, by contrast, should be employed to address complex, variegated, behaviors that require the weighing of multiple variables. Rules rely on an ex ante perspective and are therefore considered the domain of the legislator; standards embody a preference for ex post, ad-hoc, analysis and are therefore considered the domain of courts. The rules/standards dichotomy has become a …