Cornerstone Research

Economic and Financial Consulting and Expert Testimony

4 More, London Riverside, 5th Floor, London, SE1 2AU

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Cornerstone Research provides economic and financial consulting and expert testimony in all phases of complex litigation and regulatory proceedings

Glass Door
Team Size 500+
Established 1989

Cornerstone Research provides economic and financial consulting and expert testimony in all phases of complex litigation and regulatory proceedings

For more than thirty years, Cornerstone Research staff have provided economic and financial analysis in all phases of commercial litigation and regulatory proceedings.

At Cornerstone Research, we attribute our success to a unique combination of resources: a creative and energetic staff, cutting-edge technology and research, and our work with academic and industry experts. Our consultants use innovative problem-solving approaches and achieve unparalleled analytic depth. Working with faculty experts from leading business schools, economics departments, and law schools keeps us at the forefront of academic research, while industry experts share their practical experience and business acumen. Our culture of growth and collegiality provides a dynamic work environment. Our team-based approach to casework emphasizes a combination of collaboration and individual initiative. This approach offers our employees the opportunity to work with and learn from professionals at all levels of the firm as well as from a network of leading academic and industry experts.

We work with a broad network of testifying experts, including prominent faculty and industry practitioners, in a distinctive collaboration. Our staff consultants contribute expertise in economics, finance, accounting, and marketing, as well as business acumen, familiarity with the litigation process, and a commitment to produce outstanding results. The experts with whom we work bring the specialized expertise of researchers or practitioners required to meet the demands of each assignment. Cornerstone Research has earned a reputation for consistent high quality and effectiveness by delivering rigorous, state-of-the-art analysis for over 25 years.


At Cornerstone Research, you are part of a thriving staff of more than 700, spanning eight offices, comprising more than 40 nationalities, and leading the industry in its commitment to develop team members across all levels. These diverse perspectives enrich our work and enhance our culture. To learn more about our firm’s history, values, and culture, read an interview with cofounder Cindy Zollinger.

Multiple external and independent organizations have recognized our firm for providing outstanding opportunities for our team members to learn and grow. We are a winner of the Gender Equity Challenge, a prestigious award that specifically recognized our firmwide Women’s Forum initiatives. In its 2021 list of 100 Best Internships, Vault ranked our Summer Analyst Program in the top 20 among all firms surveyed. In addition, Inc. Magazine has named Cornerstone Research to its List of Best Workplaces. Selected from among thousands of entries, our firm is recognized for its commitment to teamwork, collaboration, and a vibrant, supportive culture. The array of benefits we offer is designed to provide our team members and their families with peace of mind.

Founders & Leaders

Rahul Guha Photo

Rahul Guha

Chief Executive Officer

Rahul Guha has more than two decades of experience with issues related to pharmaceuticals and healthcare. The former cohead of Cornerstone Research’s antitrust and competition practice, Dr. Guha also founded the firm’s life sciences practice. He has led the firm’s work on numerous complex antitrust and competition, intellectual property, and product misrepresentation cases, and served as a testifying expert on several life sciences matters. Dr. Guha consults on regulatory inquiries, motion practice, and all phases of litigation and arbitral proceedings in the United States and international venues. Working with counsel, he helps to develop economic and financial testimony for leading academic and industry experts. Who’s Who Legal names Dr. Guha as a leading competition economist.

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Yesim C. Richardson


Yesim Richardson specializes in applying economic and financial analysis to complex litigation involving securities, financial institutions, valuation, and real estate. Dr. Richardson has worked with clients in a variety of financial sectors as well as other industries, such as energy, telecommunications, high technology, and pharmaceuticals. She is the former head of the firm’s financial institutions practice. Dr. Richardson has addressed market efficiency, loss causation, liability, and damages in Section 10b-5, Section 11, and ERISA cases. Dr. Richardson has conducted valuation analyses of hedge funds, high-technology companies, international companies, and real estate ventures. Prior to joining Cornerstone Research, Dr. Richardson taught economics at Boston University and at Bilkent University in Turkey.

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Peter Davis

Senior Vice President

Peter Davis leads Cornerstone Research’s European competition practice and is head of the firm’s London office. Dr. Davis is an expert in competition economics and econometrics, focusing on cartel damages, merger inquiries, and market investigations (sector inquiries). He has provided expert testimony in matters before the High Court of England and Wales, the Directorate-General (DG) for Competition, the U.K. Competition and Markets Authority (CMA), and the Financial Conduct Authority. Dr. Davis has also consulted on cases in China, the Netherlands, and South Africa. His work spans a range of industries, including energy, financial services, healthcare, media, and retail. Dr. Davis is a former deputy chairman of the Competition Commission (now integrated into the CMA).

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Greg Leonard

Senior Vice President

Greg Leonard heads Cornerstone Research’s European finance practice. Dr. Leonard has nearly two decades of experience consulting for clients in complex litigation and regulatory proceedings. On behalf of clients, he has led regulatory investigations on both sides of the Atlantic, managing teams and simultaneously supporting experts across multiple related matters. In financial markets, Dr. Leonard has led engagements to evaluate risk management practices and the valuation of complex portfolios of trade positions. He has assessed Last Look features of FX client trading platforms, as well as FX algorithmic trading. In addition, Dr. Leonard has substantial experience in analyzing the execution, fulfilment, and hedging of client orders.

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Can Çeliktemur


Can Çeliktemur is a competition economist who applies advanced economic modeling and statistical techniques in complex litigation and arbitration matters. He has analyzed issues related to merger control, abuse of dominance, and cartel follow-on damages. Dr. Çeliktemur’s industry expertise covers agribusiness, automobiles, consumer electronics, energy (natural gas and solar), healthcare, and online retail. He has consulted on disputes before the Competition and Markets Authority in the UK, the Competition Commission of South Africa, and the EU Commission. Dr. Çeliktemur is the coauthor of “Innovation Theories Of Harm Are Crucial In Merger Control” and “Select Competition Cases in the UK.” The latter chapter appears in Global Competition Review’s Competition Economics Handbook.

Vivek Mani Photo

Vivek Mani


Vivek Mani has over a decade of experience leading teams and consulting to clients on regulatory and litigation issues involving competition. His expertise includes collective actions, cartels, and mergers in Europe and the United States. Mr. Mani has analyzed relevant markets, competitive effects, and damages in numerous competition matters. Who's Who Legal has recognized him as a future leader in the competition field. Mr. Mani also has experience in sampling and survey design, conducting and critiquing surveys as part of Phase II merger inquiries in Europe. In financial markets, Mr. Mani has addressed allegations of price fixing in various financial instruments. His competition experience covers a range of sectors, including automobiles, healthcare, pharmaceuticals, retail, telecommunications, and trucks.



  • Dedicated to Quality - we are dedicated to quality
  • Committed to Clients and Experts - our commitment to our people promotes a highly supportive culture
  • Committed to Our People - clients and experts rely on us
  • One-firm Firm - we are a “one-firm firm"


  • Inc. Magazine's Best Places to Work 2018, Inc. Magazine, 2020
  • Inc. Magazine's Best Workplaces 2020, Inc. Magazine, 2020
  • Economic Consultancy Firm of the Year - USA, Acquisition International Magazine, 2014
  • Top 20 of World’s Competition Economics Practices, Global Competition Review, 2014
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