Event Studies and Price Evidence

Event studies often sit at the heart of securities litigation, but too often they rest on shaky statistical ground.

My work—including a widely cited paper with Professor Alon Brav of Duke University—has been instrumental in showing that statistical significance is a poor proxy for real-world price impact. I help investors, in-house counsel, insurers, and litigation teams critically evaluate claims of impact in high-stakes matters where billions can turn on flawed or oversimplified analysis. I bring clarity to confounding effects, low power, and methodological bias—equipping clients to challenge or defend event study findings with rigor and credibility.

I am well-equipped to help clients and their experts confront the junk science that is pervasive in securities litigation.

SELECTED PUBLICATIONS

Kill Cammer: Securities Litigation Without Junk Science, William & Mary Business Law Review, 11, 417-477 (2020).

Event Studies in Securities Litigation: Low Power, Confounding Effects, and Bias, 93 Washington University Law Review pp. 583-614 (2015) (with Alon Brav). CIted by In re Allstate Corp. Sec. Litig., 966 F.3d 595 (7th Cir. 2020); In re Petrobras Sec., 862 F.3d 250 (2d Cir. 2017); In re Teva Sec. Litig., No. 3:17-CV-558 (SRU), 2021 WL 872156 (D. Conn. Mar. 9, 2021); Rooney v. EZCORP, Inc., 330 F.R.D. 439 (W.D. Tex. 2019); Monroe Cnty. Employees’ Ret. Sys. v. S. Co., 332 F.R.D. 370 (N.D. Ga. 2019); In re Chicago Bridge & Iron Co. N.V. Sec. Litig., No. 17 CIV. 01580 (LGS), 2019 WL 5287980 (S.D.N.Y. Oct. 18, 2019), report and recommendation adopted in part, No. 17 CIV. 1580 (LGS), 2020 WL 1329354 (S.D.N.Y. Mar. 23, 2020); Pirnik v. Fiat Chrysler Automobiles, N.V., 327 F.R.D. 38 (S.D.N.Y. 2018).

PRIOR TESTIMONY AS AN EXPERT WITNESS

While I now focus my work on helping others develop economic evidence as a counseling lawyer, I have experience in dealing with these issues as an expert witness. There is no substitute for understanding the problem an expert has at trial on event studies than in having developed one’s reports and given the testimony in deposition and trial. My assignments included:

Spence v. American Airlines, Inc., 23-cv-00552-O (N.D. Tex.). Expert retained by plaintiff in an ERISA action challenging the employee benefits committee of certain AA retirement plans for allegedly failing to protect investors from the ESG activism of its largest asset manager, BlackRock. Deposition (January 12, 2024); trial testimony (June 24-25, 2024).

In re Mattel, Inc. Securities Litigation, No. 219CV10860MCSPLA (C.D. Cal.). Expert for defendants Mattel, et al. regarding lack of price impact. Expert reports filed July 12, 2021 and September 1, 2021.