Education:

• S.B., Massachusetts Institute of Technology (1971)
• J.D., University of Chicago (1975)

Bar affiliations & court admissions: 

• Bar of the State of Illinois (1975)
• Bar of the State of New York (1978)
• U.S. Supreme Court
• U.S. Courts of Appeals for the Second, Third and Seventh Circuits
• U.S. District Courts for the Northern and Central Districts of Illinois, the Southern, and Eastern Districts of New York, and the Eastern District of Michigan
• U.S. Tax Court

Greg Arenson is principally a plaintiffs’ antitrust lawyer. His economics and econometrics background has provided a foundation for his recognized expertise in handling complex economic issues in antitrust cases, both as to class certification and on the merits. He has worked with economic experts in, among others, In re Air Cargo Shipping Servs. Antitrust Litig., Master File No. 06-MD-1175 (JG)(VVP), 2014 WL 7882100 (E.D.N.Y. Oct. 15, 2014), adopted in its entirety, 2015 WL 5093503 (E.D.N.Y. July 10, 2015); In re Ethylene Propylene Diene Monomer (EPDM) Antitrust Litig., 256 F.R.D. 82 (D. Conn. 2009); Dinosaur Fin. Grp. LLC v. S&P Global, Inc., Case No. 22-cv-1860 (KPF) (S.D.N.Y.); In re Pork Antitrust Litig., 18-cv-01776-JRT-JFD (D. Minn.); In re Broiler Chicken Antitrust Litig., Case No. 1:16-cv-08637 (N.D. Ill.); Affiliated Foods, Inc., et al. v. Tri-Union Seafoods, LLC d/b/a Chicken of the Sea Int’l, et al., part of In re Packaged Seafood Prods. Antitrust Litig., S.D. Cal., Case No. 15-MD-2670 JLS (MDD); In re Domestic Airline Travel Antitrust Litig., D.D.C., MDL Docket No. 2656, Misc. No. 15-1404 (CKK); and Bearings Cases, Case No. 12-00501, and Wire Harness Cases, Case No. 12-00101, part of In re Automotive Parts Antitrust Litig., E.D. Mich., Master File No. 12-md-02311. He also argued the appeals in In re High Fructose Corn Syrup Antitrust Litig., 295 F.3d 651 (7th Cir. 2002), and In re Hydrogen Peroxide Antitrust Litig., 552 F.3d 305 (3d Cir. 2009).  He has been ranked as a Super Lawyer for several years. 

Mr. Arenson has been a partner in Kaplan Fox & Kilsheimer LLP since 1993. Prior to joining Kaplan Fox, he was a partner with Proskauer Rose LLP. Earlier in his career, he was a partner with Schwartz Klink & Schreiber and an associate with Rudnick & Wolfe (now DLA Piper).

Mr. Arenson has been active in the New York State Bar Association. He is currently a member of the Audit Committee and the Committee on Law, Youth and Citizenship. He has been a member of the House of Delegates for most of the last decade and was a member of the Executive Committee of the New York State Bar Association from June 2022 through May 2026. He has been Vice Chair and a member of the Executive Committee of the Sections Caucus and a member of the New York State Bar Association Continuing Legal Education Committee. He was Chair of the Commercial and Federal Litigation Section from June 2013 through May 2014. He has been Co-Chair of the New York State Bar Association Task Force on the State of Our Courthouses, whose report was adopted by the House of Delegates on June 20, 2009; a member of the New York State Bar Association Special Committee on Standards for Pleadings in Federal Litigation, whose report was adopted by the House of Delegates on June 19, 2010; and a member of the New York State Bar Association Special Committee on Discovery and Case Management in Federal Litigation, whose report was adopted by the House of Delegates on June 23, 2012.

Mr. Arenson’s published articles include: “Losing the Forest for the Trees: On the Loss of Economic Efficiency and Equity in Federal Price-Fixing Class Actions, 16 Va L. & Bus. Rev. 293 (Spring 2022); “Rule 68 Offers of Judgment and Mootness, Especially for Collective or Class Actions,” 20 NY LITIGATOR 25 (2015); “Report on Proposed Amendments to Federal Rule of Civil Procedure 45,” 17 NY LITIGATOR 21 (2012); “Rule 8 (a)(2) After Twombly: Has There Been a Plausible Change?” 14 NY LITIGATOR 23 (2009); “Report on Proposed Federal Rule of Evidence 502,” 12 NY LITIGATOR 49 (2007); “Report: Treating the Federal Government Like Any Other Person: Toward a Consistent Application of Rule 45,” 12 NY LITIGATOR 35 (2007); “Report of the Commercial and Federal Litigation Section on the Lawsuit Abuse Reduction Act of 2005,” 11 NY LITIGATOR 26 (2006); “Report Seeking To Require Party Witnesses Located Out-Of-State Outside 100 Miles To Appear At Trial Is Not A Compelling Request,” 11 NY LITIGATOR 41 (2006); “Eliminating a Trap for the Unwary: A Proposed Revision of Federal Rule of Civil Procedure 50,” 9 NY LITIGATOR 67 (2004); “Committee Report on Rule 30(b)(6),” 9 NY LITIGATOR 72 (2004); “Who Should Bear the Burden of Producing Electronic Information?” 7 FEDERAL DISCOVERY NEWS, No. 5, at 3 (April 2001); “Work Product vs. Expert Disclosure – No One Wins,” 6 FEDERAL DISCOVERY NEWS, No. 9, at 3 (August 2000); and “Practice Tip: Reviewing Deposition Transcripts,” 6 FEDERAL DISCOVERY NEWS, No. 5, at 13 (April 2000). He was co-editor of FEDERAL RULES OF CIVIL PROCEDURE, 1993 AMENDMENTS, A PRACTICAL GUIDE, published by the New York State Bar Association; and a co-author of “Report on the Application of Statutes of Limitation in Federal Litigation,” 53 ALBANY LAW REVIEW 3 (1988).

Mr. Arenson serves as a mediator in the U.S. District Court for the Southern District of New York. In addition, he is an active alumnus of the Massachusetts Institute of Technology, having served as a member of the Corporation, a member of the Corporation Development Committee, vice president of the Association of Alumni/ae, and member of the Annual Fund Board (of which he was a past chair), secretary of his class, and co-chair of his class’s reunion gift committee.