Econometrics 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 …

Public Health Roi: Evidence, Experience And Remaining Questions, Glen P. Mays

Health Management and Policy Presentations

Expanding the delivery of efficacious public health and prevention strategies holds considerable potential for improving health outcomes and constraining costs across the U.S. health system. Unfortunately, lingering certainties about the costs required to expand public health delivery systems and about the health and economic effects of such expansions has muted private and public support for increased public health expenditures. This lecture examines recent evidence from public health services and systems research studies that examine the health and economic value of public health delivery, and identifies remaining research needs for the field.

The Science Of Public Health Delivery: Evidence, Uncertainties & Research Needs, Glen P. Mays

Health Management and Policy Presentations

Policy initiatives to reform the nation's health system increasingly recognize the need to incorporate public health and prevention strategies. The nation's delivery system for public health, however, varies widely across states and communities in its structure, authority, and capabilities. This session examines research from the growing field of public health services and systems research to identify directions for improving public health delivery.

Estimating The Value Of Public Health Services & Systems: Evidence, Uncertainties, And Research Needs, Glen P. Mays

Health Management and Policy Presentations

The Affordable Care Act authorized the largest expansion in federal funding for public health services and delivery systems in decades. These provisions, designed to support programs and services that promote health and prevent disease and injury on a population-wide basis, remain controversial because of uncertainties regarding their effectiveness in improving health and constraining medical cost growth. This session examines a series of recent studies to shed light on the health and economic value of spending on public health.