David Franklyn is a professor of intellectual property law at Arizona State University’s Sandra Day O’Connor College of Law and Executive Director of the McCarthy Institute at ASU Law. His work sits where trademark law, branding, and consumer perception meet, and he’s spent more than two decades building the empirical research behind that field.
He has consulted or qualified as an expert witness in matters across the United States, in both federal and state courts, and in Asia, the European Union, the Middle East, and South America. The consumer-perception surveys he designs and executes have been accepted into evidence by state and federal courts.
David provides expert-witness testimony, consumer-perception survey design, and rebuttal analysis in trademark, false advertising, patent, and related IP disputes. His surveys go to the questions these cases turn on: likelihood of confusion, secondary meaning, dilution, genericism, and fame, along with survey-based damages and value-apportionment work in patent matters.
He also critiques opposing experts’ surveys, identifying the methodological problems that undermine their reliability. He’s led the McCarthy Institute since 2000, which gives his practice a research foundation few testifying experts have.
David has testified by deposition or at trial in a long list of matters over the past decade. Recent examples include Collision Communications v. Samsung, where he ran a choice-based conjoint survey to measure how much consumers would pay for the patented technology at issue, with trial testimony in the Eastern District of Texas in 2025. In Chanel v. WGACA, he served as Chanel’s survey expert, with a deposition in 2021 and trial testimony in the Southern District of New York in January 2024.
His testimony history also includes Delta Air Lines v. Marriott, The Pennsylvania State University v. Vintage Brand, Omnitracs v. Motive Technologies, FCA v. Mahindra (the Jeep trade-dress matter), Polo Ralph Lauren v. U.S. Polo Association, POM Wonderful, Rockwell Automation, Nike v. Vans before the TTAB, GeigTech East Bay v. Lutron, and Hubert Hansen Family Trust v. Coca-Cola, among many others.
Over his career David has consulted for a wide range of companies and brand owners, including Apple, Amazon, Microsoft, Nike, Chanel, The Coca-Cola Company, Levi Strauss, Oracle, Spotify, Facebook, Converse, Crocs, Yeti, and the International Olympic Committee, along with matters for the Estate of Sir Arthur Conan Doyle protecting the Sherlock Holmes character.
David is editor-in-chief and co-author of McCarthy’s Desk Encyclopedia of Intellectual Property Law, written with J. Thomas McCarthy and Roger Schechter. He’s published widely on trademark law, dilution, keyword advertising, native advertising, and patent value apportionment, in the Texas Law Review, the Harvard Journal of Law and Technology, the Yale Journal of Law and Technology, the Hastings Law Journal, the Wisconsin Law Review, and the Wake Forest Law Review.
In 2016 his article “The Problem of Mop Heads in the Era of Apps,” co-authored with Adam Kuhn on value apportionment in patent law, won the Rossman Award for the most significant contribution to IP scholarship. His study “Trademark Surveys: An Undulating Path,” written with Shari Diamond for the Texas Law Review, examines the role of surveys in trademark litigation, and his article “Trademarks as Search-Engine Keywords” was named one of the best IP law review articles of 2014 and republished in the Intellectual Property Law Review.
David has taught IP and trademark law for more than 20 years, covering trademark, copyright, right of publicity, international IP, and IP survey courses. He’s a professor at ASU’s Sandra Day O’Connor College of Law and Executive Director of the McCarthy Institute, roles he’s held since 2021.
From 2018 to 2021 he was a professor of IP law at Golden Gate University, with a joint appointment in its Edward S. Ageno School of Business teaching business, marketing, and advertising, and directed the McCarthy Institute and the Center for Empirical Study of Consumer Perceptions there. From 2000 to 2018 he was a professor of IP law at the University of San Francisco, where he directed the McCarthy Institute, the Center for the Empirical Study of Trademark Law, and the LL.M. program in IP law. He was a visiting professor at UC Hastings, and earlier taught at the Salmon P. Chase College of Law at Northern Kentucky University, where he was named Outstanding Professor of the Year in 1999.
He began his legal career as a law clerk to the Honorable John Feikens in the U.S. District Court for the Eastern District of Michigan, then practiced litigation at Mayer Brown in Chicago from 1991 to 1996.