Our extensive network includes top experts from academia and industry.

Our extensive network includes top experts from academia and industry.

Ronnie Barnes

Vice President

Ronnie Barnes heads Cornerstone Research’s international arbitration and litigation practice. He also coheads the firm’s valuation, M&A, and bankruptcy practice.

Dr. Barnes is an expert in accounting, damages, and valuation. He specializes in cases that raise complex valuation issues, including the estimation of the cost of capital, the determination of country risk premia, and the valuation of complex financial instruments such as derivatives and structured finance products. Lexology Index (formerly Who’s Who Legal) has recognized Dr. Barnes as a leading expert witness in legal arbitration and a Global Leader in assessing the quantum of damages in the financial advisory and valuation field.

Dr. Barnes has provided written and oral testimony in a number of litigation and arbitration matters in the United Kingdom, United States, Canada, South Africa, and internationally. He has addressed such topics as the tax treatment of hire purchase contracts; the quantum of damages in commercial disputes; the economic equivalence of different financial derivatives; the cost of capital in the contexts of a competition enquiry and valuation disputes; the use of derivatives in alleged share price manipulation; and stock market efficiency in shareholder actions.

In addition to serving as a testifying expert, Dr. Barnes leads teams that support academic and practitioner experts. In this capacity, he has worked on numerous matters related to financial institutions and financial products. He has addressed issues related to the analysis of damages stemming from alleged misrepresentations and omissions in corporate disclosures, as well as other matters requiring sophisticated accounting, financial, and/or economic analysis.

Dr. Barnes has published research on a range of topics, notably cross-border valuation, valuation methodologies, damages, and the role of economic and econometric analyses in damages assessments. He has authored or coauthored multiple articles, as well as chapters in leading reference books on international arbitration.

A UK-qualified chartered accountant, Dr. Barnes previously held positions in accounting and investment banking firms, as well as a consulting firm and academia. He has more than a decade of experience teaching courses in corporate finance, accounting, and valuation, among other topics.

Our extensive network includes top experts from academia and industry.

René M. Stulz

Everett D. Reese Chair of Banking and Monetary Economics,
Director, Dice Center for Research in Financial Economics,
Fisher College of Business,
The Ohio State University

René Stulz is a leading finance expert, whose work focuses on corporate finance, risk management, derivatives, securities, financial institutions, and valuation. Professor Stulz has provided expert testimony in U.S. federal and state courts, U.S. and international arbitrations, the London High Court of Justice, and the Federal Court of Australia.

Professor Stulz’s findings have provided the foundation for favorable rulings in motion practice and on damages. His expert testimony played a key role in class certification and summary judgment in a number of high-profile matters, including In re BP p.l.c. Securities Litigation and In re Moody’s Corporation Securities Litigation.

He has testified in many securities class actions, as well as matters related to mortgage-backed securities and collateralized debt obligations (CDOs), bankruptcy, derivatives, cross-border transactions, alleged state discriminatory practices against investors, hedge fund and pension fund management, fixed-income securities, insurance contracts, taxes, and breach of contract allegations.

Professor Stulz was president of the American Finance Association, edited the Journal of Finance, and co-edited the Journal of Financial Economics. He wrote the textbook Risk Management and Derivatives, has edited several books, and has published more than one hundred papers in finance and economics journals. The Journal of Applied Corporate Finance dedicated its winter 2022 issue to Professor Stulz’s research, republishing his notable articles on globalization, corporate finance, and risk management.

Thomson Reuters includes Professor Stulz in its list of the world’s most influential scientific minds. He is one of the most highly cited scholars in financial economics. Lexology Index (formerly Who’s Who Legal) has recognized Professor Stulz as a leading expert witness in legal arbitration and a recommended consulting expert in assessing the quantum of damages in the financial advisory and valuation field.

Professor Stulz is a bank director and a trustee of the Global Association of Risk Professionals. He has consulted for the International Monetary Fund, the World Bank, the New York Stock Exchange, the Federal Reserve Bank of New York, and various corporations and law firms. Professor Stulz is also a research associate of the National Bureau of Economic Research (NBER) and a fellow of the European Corporate Governance Institute. At the NBER, he directs the research group on the risks of financial institutions.

Our extensive network includes top experts from academia and industry.

Gary J. Levin

Former Risk and Financial Advisory Partner,
Forensic Practice,
Deloitte Financial Advisory Services LLP

Gary Levin is an accounting and auditing expert with over four decades of experience in financial statement audits, litigation and disputes, corporate investigations, and consulting. Mr. Levin is a certified public accountant (CPA) whose expertise includes matters involving U.S. Generally Accepted Accounting Principles (GAAP) and U.S. Generally Accepted Auditing Standards (GAAS). He has submitted expert reports on various issues and testified in numerous depositions, trials, and arbitrations.

In litigation and other disputes, Mr. Levin has been retained as an expert witness to address accounting irregularities, accountant liability, damages, and due diligence issues. He has provided expert testimony in matters involving revenue recognition, percentage of completion accounting, the value of inventory and associated reserves, intangible assets, goodwill, stock options, and accounting for subsequent events, among others.

In addition, Mr. Levin has consulted on accounting and audit arbitrations in over 150 purchase price disputes, addressing accounting treatment and disputes related to working capital and earn-out provisions. In these matters, he has often served as arbitrator or mediator. Mr. Levin has also conducted forensic investigations focused on alleged asset misappropriation, channel stuffing, manipulation of accounting records, insider trading, and executive and corporate fraud.

For fifteen years, Mr. Levin led Deloitte’s Litigation and Dispute Practice and served as a financial advisory services partner in the firm. Previously, he was an audit partner at Arthur Andersen and Deloitte, leading over 500 audits of private and public companies and serving in the audit practice for almost twenty-five years. Mr. Levin’s industry expertise includes automotive, broadcasting, manufacturing, professional services, retail, and wholesale distribution.

Our extensive network includes top experts from academia and industry.

Carlyn Irwin

Senior Advisor

Carlyn Irwin is an economic damages and forensic accounting expert with over thirty years of expert witness testimony and litigation consulting experience. She specializes in intellectual property (IP), breach of contract/tort claims, financial forensic analyses, and investigations.

In addition to her expertise in calculating damages, Ms. Irwin has extensive forensic accounting experience. The Securities and Exchange Commission (SEC) has retained her to analyze financial records in matters involving flow of funds, potential asset misappropriation, and Ponzi schemes. She has provided expert testimony in federal, state, and international courts and arbitration settings.

Lexology Index (formerly Who’s Who Legal) has recognized Ms. Irwin as a leading forensic accountant in the legal investigations space, describing her as “extremely thoughtful” and citing her “detail-oriented approach” and “meticulous analysis.” A certified public accountant and certified fraud examiner, she is also certified in financial forensics, in entity and intangible valuations, and accredited in business valuation.

IP disputes

Ms. Irwin testifies on damages claims in patent, trademark, and copyright infringement matters, including multiple federal trials involving trade secret misappropriation damages. She has estimated lost profits, unjust enrichment, and reasonable royalty damages, and analyzed loss causation, apportionment issues, and the implications of “Most Favored Licensee” clauses. Her experience includes:

  • Analyzing patent and trade secret damages under Georgia-PacificPanduit, and University Computing
  • Valuing intangible assets such as patents, trade secrets, trademarks, assembled workforces, non-competition provisions, and client relationships
  • Consulting on licensing programs and pre-litigation patent matters
Contract and tort claims

Ms. Irwin analyzes and testifies on loss causation and damages in matters alleging breach of fiduciary duty, product liability, alter ego, Lanham Act violations, false advertising, unfair business competition, and defamation. She has also evaluated compensatory damages and claims for statutory and restitution or disgorgement damages. Ms. Irwin has:

  • Served as an expert in high-profile matters involving discrimination claims, as well as allegations of aiding and abetting illegal conduct and violations of federal law
  • Provided affirmative and rebuttal trial testimony in calculating damages, including analysis of loss causation issues, and opining on definitions of the but-for world
  • Testified in class action matters regarding damages at the pre-certification stage
  • Analyzed liability issues in matters alleging breach of fiduciary duty and discrimination
Financial forensic analysis

As a certified financial forensic accountant, Ms. Irwin has extensive experience with reconstructing and confirming financial records, tracing transactions through corporate reporting systems, and reviewing financial records (including tax returns) to assess consistency and reliability. She has consulted on civil and criminal white collar litigation, as well as matters alleging fraudulent conveyances, breach of contract, money laundering and racketeering (RICO), pyramid schemes, and fraud.

In her forensic accounting testimony, Ms. Irwin has addressed allegations related to solvency, financial misstatements, fraudulent/preferential transfers and schemes, and misappropriation of assets. Her work includes:

  • Testifying at deposition and trial regarding affirmative defenses that plaintiffs had falsely reported their financial condition
  • Retentions by multiple financial institutions to analyze financial transactions allegedly used to launder money and/or facilitate fraudulent customer schemes
  • Assessing companies’ solvency and the “reasonable equivalent value” of allegedly fraudulent transfers/conveyances pre-bankruptcy
  • Analyzing legal fees and costs for post-judgment reimbursement by the prevailing party

Ms. Irwin’s industry experience includes consumer products, e-commerce, entertainment, financial and professional services, healthcare, life sciences, medical devices, medical services, real estate, retail, software, software as a service (SaaS), sports, and technology. She works with clients and counsel in all phases of the litigation process.

Community engagement

Ms. Irwin is president and member of the board of directors for her local chapter of the National Charity League Inc. She previously served as treasurer and compliance officer.

International Arbitration and Litigation Capabilities

Cornerstone Research has worked with experts providing trial testimony in foreign venues, adapting our services to the standards and protocols of the different jurisdictions. For example, we applied our experience with finance and securities markets to address the issues in the first case to reach trial under Ireland’s Companies Act. In other trials, we have analyzed accounting, tax, and economic issues arising in breach of contract and intellectual property contexts.

We have consulted to attorneys involved in matters pending in major arbitral venues. We apply our expertise in finance, economics, accounting, and regulation to address complex international business issues. Our clients have included firms in the financial and professional services, energy, high-technology and consumer goods, as well as public-sector entities.

Featured Cases

Featured Insights

The Discounted Cash Flow Method of Valuing Damages in Arbitration 30 June 2025

The Discounted Cash Flow Method of Valuing Damages in Arbitration

The chapter explains key issues and concepts relating to DCF methodology.

London International Disputes Week 2025 2 June 2025

London International Disputes Week 2025

Cornerstone Research professionals and an affiliated expert will speak at this annual event focused on international dispute resolution and global ...

Cartels Workshop 2025: An Advanced Seminar on Substantive and Procedural EU Developments 23 January 2025

Cartels Workshop 2025: An Advanced Seminar on Substantive and Procedural EU Developments

Gregor Langus of Cornerstone Research will speak on a panel titled ‘Substantive Issues’ at this annual workshop in Brussels, hosted by Concurrences.

Dublin International Arbitration Day 2024 22 November 2024

Dublin International Arbitration Day 2024

Ronnie Barnes of Cornerstone Research will join a rapid-fire question-and-answer session at this annual conference in Ireland.

GAR Live: North America 2024 24 September 2024

GAR Live: North America 2024

Robert Letson of Cornerstone Research will discuss international arbitration in emerging markets at this annual Global Arbitration Review conference.

GAR Live: Damages 2024 8 February 2024

GAR Live: Damages 2024

Ronnie Barnes will join arbitrators and attorneys in a live Q&A session at this Global Arbitration Review conference in London.

WWL: Arbitration Expert Witnesses 2024 24 January 2024

WWL: Arbitration Expert Witnesses 2024

Ronnie Barnes of Cornerstone Research and René Stulz of The Ohio State University named to expert witness list.

Cartels Workshop 2024: An Advanced Seminar on Substantive and Procedural EU Developments 18 January 2024

Cartels Workshop 2024: An Advanced Seminar on Substantive and Procedural EU Developments

Gregor Langus will speak on a panel titled ‘Substantive Issues’ at this annual workshop in Brussels.

GAR Academy Damages in International Arbitration 30 November 2023

GAR Academy Damages in International Arbitration

Ronnie Barnes serves as a faculty member in GAR Academy’s Damages in International Arbitration Massive Open Online Course (MOOC).

Dublin International Arbitration Day 2023 17 November 2023

Dublin International Arbitration Day 2023

Ronnie Barnes will moderate a panel titled, ‘Arbitration, Bankruptcy & Sanctions,’ at this annual conference in Ireland.

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