Dr. Williams has provided testimony before the US District Courts for the Middle District of Alabama; Western District of Arkansas; Central, Northern, and Southern Districts of California; District of Delaware; Middle District of Florida; Northern District of Georgia; Eastern Division, District of Idaho; Northern District of Illinois; Southern District of Illinois; District of Kansas; District of Massachusetts; District of Minnesota; District of New Jersey; Southern District of New York; Eastern District of Pennsylvania; Eastern District of Tennessee; Northern and Southern Districts of Texas; and District of Utah. He has also provided testimony before the US Court of Federal Claims; State of Connecticut, Superior Court; State of New Mexico, Second Judicial District; State of Nevada, Gaming Commission and State Gaming Control Board; public utilities commissions in the states of Arkansas, Hawaii, Michigan, Minnesota, Missouri, Nebraska, New Mexico, Texas, and Washington; and The Netherlands, Amsterdam District Court.
Dr. Williams has published articles in a number of academic journals, including the Proceedings of the National Academy of Sciences, American Economic Review, Journal of Industrial Economics, International Journal of Industrial Organization, Journal of Law and Economics, American Law and Economics Review, Journal of Economics and Management Strategy, Review of Industrial Organization, Journal of Institutional and Theoretical Economics, Economics Letters, Journal of Public Economic Theory, Behavioral Science, Antitrust Bulletin, Physica A, Texas Law Review, and Yale Journal on Regulation.