Unrelenting Innovation—G.J. Tellis. (Jossey-Bass, San Francisco, a John Wiley and Sons Imprint, 332 pp., 2013, $34.95). Reviewed by John E. Ettlie

Gerald Tellis, a professor of marketing at the University of Southern California, Los Angeles, CA, USA, has just published a look at a problem long-recognized but unresolved in the field of innovation: Why is it that incumbent firms that come to dominate their markets fail to maintain their strong market positions very long? His thesis is that corporate culture is both the cause and the cure for the innovation challenge. Prof. Tellis gives numerous examples of companies that have fallen from on high in their markets like Sony, Kodak, Research in Motion (Blackberry), Nokia in mobile phones, Sears, and the list goes on and on. Many other experts have written about this problem, among them Clay Christensen and Michael Tushman, but Prof. Tellis has a unique view of the underlying causes of this problem and the potential solutions which make this book worth reading. Tellis offers a fresh view, building on much prior research. The book presents the causes for the challenge of maintaining a dominant position through innovation. Prof. Tellis argues that the root cause of the problem is the "incumbent curse," which is a "self-destructive culture that results from their prior success". The leading incumbents fear cannibalizing their current successful products and respond too late to competitors to save themselves.