I’d like to share with the readers of the blog the latest working paper of mine titled “*To Pool or Not to Pool: A Closer Look at the Use of Sub-regressions in Antitrust Class Certification*,” available for download from SSRN at the link [here].
A central question regarding class certification is whether the conduct in question impacted all or nearly all class members. To answer this question, a methodology, known as sub-regressions, has been proposed and employed by economists in several recent class action cases. A key step of a typical sub-regression analysis, at a high level, is to divide the data into subgroups and then examine the impact question separately. In this article, I takes a close look at three areas of interest related to this methodology:
- First, I compare and contrast various related proposals in the law and economics literature and document the ongoing debate among commentators on the usefulness of the methodology.
- Second, I analyze courts’ recent class certification decisions in cases where this type of analysis was introduced. I argue that just like any other methodology, the probative value of sub-regression type analysis should be assessed together with the collection of other evidence. And this is exactly what the courts have done.
- Last, I discuss a number methodological issues with sub-regressions–many unacknowledged previously–and explain why a disciplined and rigorous implementation is crucial for its reliability. By understanding these issues, even at a high level, attorneys will be able to help ensure that their expert witnesses perform convincing sub-regression type analysis and understand the potential challenges to their work.
It is worth noting that while I focus on antitrust cases (cartel cases in particular) in this article, the discussions should be relevant to all other types of class action cases.
As always, I appreciate your thoughts and comments. You can reach me at firstname.lastname@example.org or connect with me on LinkedIn [here].
Ai Deng, PhD
Principal, Bates White Economic Consulting
Lecturer, Advanced Academic Program, Johns Hopkins University
direct: 2022161802 | fax: 2024087838
1300 Eye Street NW, Suite 600, Washington, DC 20005