Dr. McWilliams is professor of marking in the department of Business Administration in ITAM. He received his Ph. D and Masters from the Department of Agricultural and Resource Economics of the University of California at Berkeley. His undergraduate studies were in Economics at San Francisco State University.

He currently does research in the areas of international trade and marketing. His research in international trade examines the relationship between firm productivity and export intensity, and how different consumer segments can gain or lose from international trade or from being part of larger federations. This research helps explain, for example, how many consumers in the US can be against trade or how consumers in Catalonia in Spain or Quebec in Canada may want to separate from the rest of their respective countries.

His research in marketing addresses issues of consumer risk in purchasing products for which the quality is uncertain. Retailers and firms can use money-back guarantee, sampling, demonstrations, or other marketing tools to help reduce consumer uncertainty at the time of purchase.

Professor McWilliams has taught Marketing I, Marketing III, International Marketing and Services Marketing at the undergraduate level. At the masters level he has taught Marketing Management, International Marketing and Marketing in Developed Countries.