 His commentaries have appeared in media outlets such as the "New York Times, Wall Street Journal, Los Angeles Times", BusinessWeek.com, Huffington Post, Kiplinger, "Financial Times of London, San Francisco Chronicle" and the "Democrat and Chronicle".Zupan is the co-author of two books, "Microeconomic Theory and Applications" (with E. K. Browning) published by John Wiley and Sons, and "Microeconomic Cases and Applications" (with T.W.Gilligan and A.M. Marino), published by HarperCollins.