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The following is an excerpt from Practice Perspectives: Vault's Guide to Legal Practice Areas.

Sonia Kuester Pfaffenroth focuses her practice on helping clients address complex antitrust issues in the US and globally. She rejoined the firm in 2017 from the Antitrust Division of the US Department of Justice (DOJ) where she served most recently as Deputy Assistant Attorney General for Civil and Criminal Operations. In that role, Ms. Pfaffenroth was responsible for supervising both civil and criminal antitrust enforcement efforts, as well as the Division's work with antitrust and competition law enforcement agencies worldwide.

While at the DOJ, Ms. Pfaffenroth oversaw a number of the Division's most significant matters, including the Division's challenges to the Anthem/Cigna and Aetna/Humana mergers and the American Express litigation. In addition to her responsibilities with respect to the Division's international program, she also supervised a broad range of legal policy initiatives and competition advocacy efforts. 

Before leaving to join the DOJ in 2013, Ms. Pfaffenroth was a partner at the firm, where she represented companies in a range of industries in international cartel investigations, merger and acquisition reviews, and civil antitrust litigation, as well as providing day-to-day antitrust counseling.

Describe your practice area and what it entails.

I have been an antitrust practitioner since I first joined Arnold & Porter. I primarily represent companies in civil antitrust litigation and government investigations—both civil and criminal. I assist clients with antitrust compliance and training and provide day-to-day counseling on a wide variety of competition issues—pricing, marketing, distribution, contracting, trade association activities, R&D and other collaborations—to assist clients in identifying potential areas of antitrust exposure and to help formulate creative solutions to achieve the desired business objectives while lowering risk.

What types of clients do you represent?

I represent a broad range of clients across different industries, including life sciences, manufacturing, and technology. One of the most interesting aspects of being an antitrust attorney is the opportunity to apply general legal principles relating to competition across industries with markedly different competitive dynamics. There is no “one size fits all” answer, but experience in one industry can inform how to consider issues posed in another.

What types of cases/deals do you work on?

While some antitrust attorneys may focus primarily on certain industries or certain types of matters, I practice across areas—merger investigations, cartel investigations, internal investigations and compliance counseling, with a particular focus on private antitrust litigation. I have defended clients in government investigations and civil litigation relating to allegations of price-fixing and bid rigging. I have represented companies in private civil litigation involving claims of monopolization and exclusive dealing. I have advised clients in merger investigations, and I have defended clients in litigation resulting from acquisitions. Although I have been an antitrust practitioner for many years, I have been fortunate to maintain a varied practice throughout.

How did you choose this practice area?

I started out as a general litigator, but fairly quickly determined that I was interested in developing a more specialized practice. I explored several different areas, and antitrust provided the perfect combination of complex legal issues and economics, paired with the opportunity to develop a deep knowledge of the client’s business. For attorneys who are interested in not just legal issues, but also the ability to assist in strategic considerations as clients contemplate different potential business opportunities, antitrust lies at the intersection.

What is a typical day like and/or what are some common tasks you perform?

Every day is different—which is what keeps the practice interesting and exciting. It is highly dependent on each individual case. Any given day could be occupied by client meetings, legal team meetings, witness interviews, depositions, legal briefing, meetings with the government or opposing counsel or co-counsel or experts. Perhaps what is most interesting are the unexpected calls—either from clients or from colleagues—raising an interesting and unique competition law question. Those are often the most challenging—helping on an ad hoc basis to spot issues and risks and to work collaboratively to identify the optimal solution to the problem posed.

What training, classes, experience, or skills development would you recommend to someone who wishes to enter your practice area?

For those still in school—take an antitrust class or classes in economics. It can help you decide if antitrust is an area that really interests you, and it is a fascinating subject to explore even if it does not end up being your area of primary practice. In terms of skills, particularly as a junior attorney, I encourage associates not to specialize too early on. Focus on developing experience in litigation, internal investigations and deal work. Work on branching out across areas of substantive expertise and work to develop “niche” expertise that you can bring to bear across clients. Having a broad experience base allows you to be nimble and pivot between assignments and clients. It also provides the opportunity to work with variety of more senior attorneys, who may develop into mentors as your career develops. And, perhaps most importantly, working on a variety of different matters can help you determine what types of work you personally find the most fulfilling.

What do you like best about your practice area?

Antitrust analyses are rarely clear cut—to be able to accurately assess the legal implications of any given course of conduct requires developing a deep understanding of the markets involved and the competitive dynamics at play. Antitrust cases provide the opportunity—and the necessity—to really understand the economics of an industry and the individual competitors within that industry. It is that fact-intensive inquiry that I consider to be the most compelling, whether it is in the context of a litigation over business decisions that have already been made or looking forward to determine the competitive implications of a planned future business strategy.

What is unique about your practice area at your firm?

Being a part of a large, multifaceted antitrust group with a deep bench in terms of both substantive expertise and industry experience positions us well to assist our clients with any competition-related issue that emerges. Regardless of the question posed, chances are high that someone in our practice group will have relevant experience. We are a highly collaborative and collegial group and knowing that it is always possible to pick up the phone to get the benefit of a colleague’s experience—or just to brainstorm creative solutions to a tricky question—is what drew me back to Arnold & Porter after spending several years in government service. Arnold & Porter prioritizes client-focused solutions, and that means having the opportunity to work not only with talented colleagues in the antitrust group, but across the firm—with our life sciences, litigation, and white collar colleagues, for example—which is one of the key benefits of practicing at Arnold & Porter.

What are some typical tasks that a junior lawyer would perform in this practice area?

Junior attorneys may assist in a wide range of tasks—including research, brief writing, preparation for depositions, witness interviews, document discovery—depending on the requirements of any given matter. But, a key opportunity for junior attorneys—regardless of whether it is a litigation or an investigation—is to become the fact expert. While antitrust practice offers a lot of interesting legal questions (often intermixed with important policy questions about the role of antitrust), most antitrust matters turn on the facts. As the team member who is typically the closest to the documents, the junior attorney is also the closest to the facts. Junior attorneys should seek out opportunities to use the detailed knowledge they develop in discovery or in the course of an investigation to seek out opportunities for additional responsibilities. Always be trying to think ahead strategically. In my view, one of the highest compliments a more senior attorney can give is to describe a more junior attorney as “looking around corners” and flagging issues affirmatively—not just responding to assignments.

What are some typical career paths for lawyers in this practice area?

I would not say there is a “typical” career path. There are opportunities for antitrust practitioners in both the private and public sectors—or a combination of the two—at all levels of experience. Some antitrust attorneys may spend their entire careers working in government enforcement or transition to private practice mid-career. Others start their careers at law firm and later move into public service and sometimes back again. Still others bring their competition expertise honed in the government or in private practice in-house. There is no “right” path. I practiced at Arnold & Porter for almost eight years and then served in several positions in the Antitrust Division of the Department of Justice, including as Deputy Assistant Attorney General, before returning to the firm several years later. One of the key advantages of deciding to specialize in antitrust is the wide variety of potential career paths you can pursue.