Greg Eastman

Senior Vice President


  • Washington


Greg Eastman coheads Cornerstone Research’s commercial disputes and general damages practice. Dr. Eastman analyzes complex economic and accounting issues related to tax, mergers, securities and financial products, and healthcare. He has extensive trial and arbitration expertise and directs large teams supporting multiple experts.

As a testifying expert, Dr. Eastman has addressed profitability, cost efficiencies, class certification, valuation and damages, and unjust enrichment issues. He has provided testimony before the Commodity Futures Trading Commission, the Department of Justice (DOJ), and the Federal Bureau of Investigation. Dr. Eastman has more than twenty years of experience consulting in a range of industries, including electric utilities, energy, financial institutions, insurance, medical services, nuclear utilities, oil, private equity, and transportation.

Tax controversy

In his tax controversy work, Dr. Eastman has analyzed the economic substance and business purpose of transactions. He has reviewed structured transactions, assessed a multinational company’s debt capacity, analyzed guarantee fee payments, and evaluated the risk management functions of a multinational financial institution. In addition, he has worked on cases involving transfer pricing, the relative value of software components, and the manufacturing and Food and Drug Administration approval processes for medical devices.

Dr. Eastman’s tax accounting work has covered stock option awards, uncertain tax benefits, deferred tax assets, and net operating loss carryforwards. He supported experts on tax accounting and poison pill issues in the Selectica, Inc. v. Versata Enterprises, Inc., and Trilogy, Inc. trial in the Delaware Court of Chancery.

Merger efficiencies and failing firm analysis

Dr. Eastman has been retained as a testifying expert to assess merger-specificity and verifiability of claimed efficiencies in multiple industries. He helped to estimate the profitability of the individual commercial health insurance business in the Aetna/Humana merger. Dr. Eastman has also been retained to perform profitability analyses and to assess whether firms are failing and their assets are likely to exit the relevant market. He was the DOJ’s testifying expert in United States v. EnergySolutions Inc. et al.


Dr. Eastman has led a variety of consulting projects involving accounting and financial reporting issues. In these matters, he has evaluated the adequacy of disclosures, fair value and asset impairments, materiality, goodwill, accounting for loan losses, concentrations of risk, revenue recognition, and other issues pertaining to whether financial statements were prepared in accordance with generally accepted accounting principles (GAAP) and whether audit and review procedures complied with generally accepted auditing standards (GAAS).

Securities and financial products

Dr. Eastman has conducted liability and damages analyses in securities class actions, including In re Vivendi Securities LitigationIn re Omnicom Securities Litigation, and In re Williams Securities Litigation. In financial cases, he has analyzed issues related to debt and equity securities, derivative contracts, mutual fund trading, cost of capital, real estate investments, private equity investments, and valuation. He worked with experts on insider trading and failure to report transactions in the SEC v. Samuel E. Wyly et al. trial. Dr. Eastman also supported multiple experts in a trial involving risks and investment returns in a large portfolio of high-yield bonds.


Dr. Eastman has performed drug valuations in multiple contexts, including in appraisal and breach of contract cases. As the testifying expert in an international arbitration, he estimated damages related to allegations of breach of contract to market a drug. He has also analyzed medical devices, cord blood services, cancer treatment services, and other healthcare-related industries. Dr. Eastman worked on firm profitability and cost efficiencies issues in the Aetna/Humana and Anthem/Cigna proposed mergers. He was retained as a testifying expert to analyze cost efficiencies and failing firm defenses in a hospital and physician practice merger.


Secure Energy Services Inc./Tervita Corporation

Press Release

Cornerstone Research Staff and Affiliated Experts Submit Comments to the Joint FTC-DOJ Inquiry on Merger Enforcement


Pro Bono: New York State Citizens’ Coalition for Children v. Poole


MergerFest 2020: Alternative Counterfactuals in Merger Enforcement: Key Takeaways


In the Matter of DraftKings Inc. and FanDuel Limited

Press Release

Cornerstone Research Promotes Five to Senior Vice President


5 Questions with Greg Eastman and Ceren Canal Aruoba: The Horizontal Merger Guidelines and the Failing Firm Defense


Non-Standard Counterfactuals in Merger Control

  • “Failing Firm Defense: Shop ‘Til You Drop?,” American Bar Association Section of Antitrust Law Spring Meeting, 11 April 2018