Addressing High-Stakes Economic Issues
Agency experience

Our consultants and affiliated experts have experience working at or consulting for enforcement and regulatory agencies, including the Department of Justice, the Federal Trade Commission, the U.K. Competition Commission, the Federal Communications Commission, and other agencies around the world.

Competition issues

Our staff and experts are at the forefront of using sophisticated econometric demand models and merger simulation tools to analyze the likely competitive effects of a merger and any proposed divestitures. We draw on qualitative and quantitative evidence from multiple sources to provide understandable, coherent, and robust descriptions of relevant geographic and product markets, competitive effects, and other factors.

Real-world evidence

Econometric models reinforced by qualitative evidence such as ordinary course of business documents and fact witness testimony can provide a basis for credible and persuasive expert testimony. Our experts are adept at incorporating such evidence, helping to ensure that their analyses are consistent with industry realities and the way the merging parties think about how their consumers make choices.

Big data and survey analysis

Cornerstone Research staff and experts regularly work with datasets containing billions of records. Clients frequently rely on us to compile large datasets from disparate sources and incompatible formats to address the economic issues that arise in mergers. We also have extensive experience in constructing surveys, analyzing market-based data, and critiquing survey methodologies.

Accounting issues

Our staff and experts with financial statement or accounting expertise can provide valuable input in merger challenges where parties assert efficiency claims or “failing firm” defenses. Such analyses can include assessment of merger specificity and verifiability of claimed efficiencies. Our experts have been asked to assess a target firm’s financial condition, the risk of its key assets leaving the market absent the merger, and whether the firm has made good faith efforts to elicit reasonable alternative offers.

Our extensive network includes top experts from academia and industry.

Our extensive network includes top experts from academia and industry.

Joanna Tsai

Vice President

Joanna Tsai coheads Cornerstone Research’s merger investigations practice in Washington, DC. Dr. Tsai provides economic consulting and expert testimony in high-stakes mergers, acquisitions, and antitrust regulatory investigations. She brings nearly twenty years of experience in private practice, government, and academia to address a range of merger, antitrust, and competition issues. As an economic expert retained by merging parties for complex transactions, she has presented economic analyses and authored white papers and expert reports on proposed transactions before competition agencies in the U.S. and Europe, as well as in China and Brazil.

From 2013 to 2015, Dr. Tsai served as economic advisor to a Commissioner at the Federal Trade Commission (FTC). In that role, she advised on competition, intellectual property, and consumer protection issues, including those related to enforcement decisions, antitrust policy, litigation strategy, and rulemaking.

Who’s Who Legal has recognized Dr. Tsai as a Thought Leader among competition economists, and for four consecutive years named her a Future Leader in the competition field.

Antitrust merger reviews

Dr. Tsai has served as an economic expert in numerous mergers and joint venture transactions. She has extensive expertise in merger investigations, and has presented economic analyses before the FTC, the Department of Justice (DOJ), and the European Commission, among others.

Dr. Tsai analyzes the competitive and economic implications of mergers and evaluates a variety of issues in this context, including potential unilateral effects, vertical effects, coordinated effects, potential and nascent competition, and market definition. Merging parties retain her to conduct pre-deal risk assessments for potential targets and deal structures, as well as to assist with advocacy in front of the agencies. Dr. Tsai also supports parties through second requests, front office meetings, and commissioner meetings. In Evonik’s acquisition of PeroxyChem, a matter contested by the FTC, she assisted the parties in closing the transaction through litigation.

Dr. Tsai’s industry experience for mergers includes agriculture and food, biotech and biosolutions, e-commerce and platforms, pharmaceuticals, medical devices, industrial gas, chemicals, consumer products, technology, retail (supermarkets, pharmacies), industrial product manufacturing, gaming and hospitality, and financial services.

Antitrust and intellectual property

Dr. Tsai has extensive experience consulting on the economic aspects of antitrust claims. She recently served as economic expert in a mediation between two major healthcare solutions companies, analyzing the competition implications of their licensing terms.

Dr. Tsai’s expertise includes matters involving DOJ allegations of anticompetitive conduct, notably in the technology sector. In a case involving DOJ claims of bid-rigging, Dr. Tsai led a team to assess the Agency’s allegations and demonstrated that the economic evidence was inconsistent with what one would expect to see had bid-rigging occurred.

Thought leadership

A frequent speaker on antitrust and intellectual property topics, Dr. Tsai presents at academic and industry conferences in the U.S. and internationally. She has published research in the Antitrust Source, the Antitrust Bulletin, Antitrust Magazine, and the Antitrust Law Journal. Dr. Tsai cochairs the Transportation and Energy Industries Committee of the Section of Antitrust Law of the American Bar Association (ABA). Previously, she cochaired the Section’s Mergers and Acquisitions and Economics Committees.

Dr. Tsai has served as faculty at Stanford University’s Hoover IP2 Summer Institute on the Economics and Politics of Innovation. As an adjunct professor at the University of Puerto Rico School of Law, she designed and taught a course on principles of economics for lawyers. Dr. Tsai has also held senior roles at several economic consulting firms.

Our extensive network includes top experts from academia and industry.

Andrew Sweeting

Professor, Department of Economics,
University of Maryland, College Park;
Former Director, Bureau of Economics,
U.S. Federal Trade Commission

Andrew Sweeting is a former director of the U.S. Federal Trade Commission’s (FTC’s) Bureau of Economics. An industrial organization economist, Professor Sweeting specializes in competition and antitrust, including merger analysis, applied econometrics, and structural modeling.

While at the FTC, Professor Sweeting oversaw many merger investigations conducted by the Agency, and was director when the 2020 Vertical Merger Guidelines were released. He was also involved in high-profile consumer protection investigations, including several related to digital platforms and data security. In addition to his tenure at the FTC, Professor Sweeting has served as an academic visitor at the U.S. Department of Justice’s Economic Analysis Group, and as an expert on the Academic Panel of the U.K. Competition Commission (now the U.K. Competition and Markets Authority).

Global Competition Review recognized Professor Sweeting to its inaugural list of the world’s most important antitrust academics. His wide-ranging research has analyzed the impact of mergers on prices, product variety, and product repositioning. He has also addressed collusion in wholesale electricity markets, the performance of different auction designs, dynamic pricing in online resale markets, and the effects of alternative copyright policies in the radio industry. In addition, he has researched the effect of government bailouts, how targeted advertising affects market structure and competition, and firms’ strategic use of pricing and capacity choices to influence future competition.

Professor Sweeting has conducted empirical research in a range of industries, including radio, television, advertising, consumer packaged goods, energy markets, online resale markets, transportation, and government procurement and timber auctions.

A widely published author, Professor Sweeting’s work has appeared in leading economics journals, such as Econometrica, the American Economic Review, the Journal of Political Economy, and the RAND Journal of Economics. He has been awarded several multiyear research grants from the National Science Foundation. In 2018, he received the Robert F. Lanzillotti Prize for the best paper in antitrust economics for a coauthored article on post-merger repositioning in the airline industry.

Professor Sweeting is a former editor of the Journal of Industrial Economics and a former foreign editor of the Review of Economic Studies. He is a research associate of the National Bureau of Economic Research (NBER) and a research fellow of the Centre for Economic Policy Research (CEPR).

In his more than two decades as an educator, Professor Sweeting has been honored numerous times for excellence in teaching. Before joining the faculty of the University of Maryland, he held positions at Duke University, Northwestern University, and St. Catherine’s College, Oxford.

Our extensive network includes top experts from academia and industry.

Nathan Miller

McDonough School of Business and Department of Economics,
Georgetown University

Nathan Miller is an antitrust expert who consults on high-stakes merger and other enforcement investigations. His research covers industrial organization, finance, and regulation, with a focus on merger investigations, cartels, tacit coordination, and price discrimination.

On behalf of merging parties, Professor Miller has addressed competitive effects, including upstream and downstream aspects, in a variety of complex matters, including the proposed $67 billion acquisition of Express Scripts by Cigna. He has also been retained as an expert witness in merger investigations brought by U.S. and international agencies.

Professor Miller’s testimony on behalf of U.S. agencies includes retentions by the Department of Justice (DOJ) in U.S. and Plaintiff States v. American Airlines Group Inc. and JetBlue Airways Corp. The opinion in that matter frequently echoed Professor Miller’s testimony; a judge sided with the DOJ and ruled that American Airlines and JetBlue must undo their Northeast Alliance.

The Federal Trade Commission (FTC) retained Professor Miller in its investigation into Tronox Holdings plc.’s proposed $300 million acquisition of TiZir Titanium and Iron. Also on behalf of the FTC, Professor Miller analyzed US Foods Inc.’s proposed $1.8 billion acquisition of Services Group of America Inc. and Edgewell Personal Care Company’s proposed $1.37 billion acquisition of its competitor, Harry’s Inc.

The Canadian Competition Bureau retained Professor Miller in Secure Energy Services Inc./Tervita Corporation, a transaction between Canada’s two largest waste service providers. In its ruling, the Competition Tribunal found Dr. Miller “knowledgeable, helpful, candid, and forthcoming with the panel” and “genuinely interested in assisting the Tribunal to make the right determinations.”

As a former staff economist for the Antitrust Division of the DOJ, Professor Miller assessed an array of complex mergers, notably Bazaarvoice/PowerReviews, AT&T/T-Mobile, and Ticketmaster/Live Nation. For analysis related to the AT&T/T-Mobile merger, he received the Antitrust Division’s Assistant Attorney General (AAG) Award.

Professor Miller’s research has appeared in journals such as the American Economic ReviewEconometrica, the RAND Journal of Economics, the Journal of Finance, and the Journal of Financial Economics. His 2022 coauthored article on market power trends was awarded the Industrial Organization Society’s Robert F. Lanzillotti Prize for the best paper in antitrust economics. Professor Miller also won the Lanzillotti Prize in 2015 for his paper on coordinated effects.

At Georgetown, Professor Miller teaches courses to graduate students on strategic pricing, microeconomics, and firm analysis and strategy. Earlier in his career at the university, he was recognized as a Provost’s Distinguished Associate Professor based on excellence in research, teaching, and service. He serves as a senior policy scholar at the Center for Business and Public Policy at Georgetown’s McDonough School of Business.

Who’s Who Legal has recognized Professor Miller as a “definite future leader” in the competition field. Global Competition Review named him to its inaugural list of the world’s most important antitrust academics.

Our extensive network includes top experts from academia and industry.

Gautam Gowrisankaran

Professor of Economics,
Columbia University;
Senior Advisor, Cornerstone Research

Gautam Gowrisankaran is an expert in industrial organization, healthcare economics, and energy and environmental economics. Professor Gowrisankaran has analyzed issues of market definition and market power, the competitive effects of mergers, and claims of attempted monopolization. He has also addressed allegations of tying, foreclosure, and other exclusionary practices arising in such industries as healthcare, consumer goods, high-tech products, payment services, and transportation.

An experienced expert witness, Professor Gowrisankaran has been retained by federal and state agencies as well as by private clients in numerous high-profile mergers, antitrust litigation matters, and consumer class actions. His trial testimony includes United States of America et al. v. JetBlue Airways Corporation and Spirit Airlines Inc.United States et al. v. UnitedHealth Group Inc. and Change Healthcare Inc.Sidibe v. Sutter HealthIn re: Purdue Pharma L.P. et al.; and Federal Trade Commission v. Hackensack Meridian Health Inc. and Englewood Healthcare Foundation. He has consulted to the Federal Trade Commission (FTC) on retail and technology issues and the Antitrust Division of the Department of Justice (DOJ) on airline matters and mergers in the healthcare space.

In his research, Professor Gowrisankaran conducts both theoretical and empirical studies of topics related to industrial organization and competition. He has particular expertise in industries that are highly regulated and exhibit rapid technological change, such as healthcare and energy, as well as markets in which prices are negotiated.

One focus of Professor Gowrisankaran’s recent research is energy, including renewable energy integration, electricity regulation in the presence of energy transitions, and enforcement of environmental laws. He has also analyzed a variety of issues in healthcare markets, such as hospital competition, the impact of countervailing health insurer market power, and the price impact of hospital mergers.

A prolific author, Professor Gowrisankaran has published research in leading economics journals, including the American Economic ReviewEconometrica, and the Journal of Political Economy. He has served on the editorial boards of several academic journals, including the American Economic Review and the RAND Journal of Economics. In addition, Professor Gowrisankaran has written analyses for a legal audience, including in the Antitrust Law Journal. He has been honored with best paper awards and recognized by Who’s Who Legal as a leading competition economist.

Global Competition Review recognized Professor Gowrisankaran in its inaugural list of the world’s most important antitrust academics. He was also honored in Lexology’s 2022 Client Choice list.

Prior to joining the faculty at Columbia, Professor Gowrisankaran was a tenured professor of economics and the Peter and Nancy Salter Chair in Healthcare Management at the University of Arizona. He has held visiting academic appointments at Northwestern University, the University of Chicago, Yale University, and Harvard University, among others.

Professor Gowrisankaran serves on the U.S. Congressional Budget Office Health Advisory Panel. He is a research associate at the National Bureau of Economic Research (NBER) and a research fellow at the Center for Economic and Policy Research (CEPR).

Merger Investigations Capabilities

Before a deal comes before the agencies, we provide merging parties with assessments of antitrust risks and strategies to address potential agency concerns. Consulting while the deal is being structured can help parties avoid costly and disruptive reviews.

For merging parties, it is important to understand the agency’s concerns and educate the agency on how the specific industry or market operates. If an agency is sufficiently concerned about harm to competition at the end of the initial review period to proceed to a second request, Cornerstone Research works with merging parties to respond to agency requests, including assisting with data and document production as well as providing analytical support for expert white papers or presentations to the agency.

Our credibility with the agencies enables us to communicate effectively on behalf of merging parties. We are also frequently retained by the agencies to offer independent opinions about whether a merger raises antitrust concerns.

On behalf of merging parties and U.S. government agencies, Cornerstone Research has supported testifying experts in some of the highest-profile merger review cases in recent years. We have the experience and skills to help counsel seamlessly transition to litigation and meet the compressed deadlines common in merger litigation.

With offices across the United States and in the United Kingdom, Cornerstone Research provides the expertise and capabilities to assist in mergers being reviewed internationally. Our affiliated experts have advised parties in merger proceedings before enforcement bodies throughout the world, including Europe, the United Kingdom, and China.

Assessing failing firm arguments from both the regulatory and merging parties’ perspectives enables us to provide insight into the rigorous demands of this defense.

Featured Cases

Featured Publications

7 May 2024

Assessing the Potential for Incentives to Raise Prices in Multi-Sided Platform Mergers

The authors review the challenges of assessing anticompetitive pricing incentives in horizontal multi-sided platform mergers.

2 May 2024

Entrenching and Leveraging Market Dominance in the 2023 Merger Guidelines: Insights from Amgen/Horizon

Insights from Amgen/Horizon merger on leveraging market dominance via bundling under 2023 Merger Guidelines.

10 April 2024

Cornerstone Research Staff and Affiliated Expert Win 2024 Antitrust Writing Awards

Concurrences Review recognized winners in the intellectual property and mergers categories, selected from leading antitrust and competition article...

17 March 2024

2023 Merger Guidelines Addressing Potential Impacts on Workers

In this article from The Threshold, the authors recap an American Bar Association panel on theories of labor harm in mergers.

23 February 2024

Cornerstone Research Shortlisted for 2024 GCR Awards

Global Competition Review recognizes the firm’s work on high-profile 2023 matters, and shortlists Celeste Saravia as Economist of the Year.

20 February 2024

Brussels Team Expands with Experienced Competition Hire

Dr. Norbert Maier joins Cornerstone Research, with deep antitrust law and competition expertise from the EU Commission DG COMP team.

8 February 2024

Trends in Merger Investigations and Enforcement at the U.S. Antitrust Agencies: Fiscal Years 2005-2022

In fiscal year 2022, merger transactions and second requests decreased from the prior year.

7 February 2024

Assessing Merger Guideline Feedback With Machine Learning

This article analyzes the results of large language model processing to reveal several important patterns in the comments to the draft merger guide...

5 February 2024

Cornerstone Research Named Among 2024 Outstanding Global Economic Consultancies

Global Competition Review describes the firm as “ideally placed to tackle the most complex and demanding competition mandates.”

22 January 2024

Dr. Ari Gerstle Joins Cornerstone Research as Senior Advisor and Expert

Renowned economist with over 20 years in the DOJ's Antitrust Division has joined the firm.

How can we help you?

For more information or assistance with a specific matter, please contact us.