Phil Rosenzweig

Author, Left Brain, Right Stuff and The Halo Effect

Developing clearer thinking about business and management.

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How can business leaders make better decisions? What really affects company performance? Phil Rosenzweig explores these questions in depth, providing sophisticated, practical advice.

His latest book, Left Brain, Right Stuff, takes a characteristically deep look at the problem of better decision-making. Phil concludes that great leadership requires two characteristics — critical and analytic skills (“left brain”) as well as inspiring, decisive action (“right stuff”). The many different types of decisions leaders face each require a different combination of these two qualities. Most decision-making advice neglects the “right stuff” in favour of simple critical-thinking tips; Left Brain, Right Stuff finally offers the full picture of how to make great decisions as a well-rounded leader.

Phil’s previous book was The Halo Effect (and the Eight Other Business Delusions That Deceive Managers). Taking a stance against the quick fixes offered by typical management gurus, Phil unmasks the wrong assumptions, shoddy research and superficial recommendations that delude people into thinking that they fully understand success and failure in business. The Halo Effect represents a new way of thinking about business: its goal is not to make managers smarter (they’re already plenty smart!) but wiser, more discerning, more appropriately sceptical, and less vulnerable to simplistic formulas.

Phil’s presentations — provocative, contrarian, amusing, and inspiring — carry that approach forward, challenging you to think more clearly and help you separate fact from fiction. Dispelling the bad ideas that pass as business knowledge, Phil explains not what to think — which nobody can claim to teach you; he explains how to think.

Phil Rosenzweig is a Professor at IMD, the International Institute for Management Development, in Lausanne, Switzerland, where he works on executive development programs for leading companies on questions of strategy and organisation. He has a Ph.D. from the Wharton School and was on the faculty of Harvard Business School. Phil has taught extensively in executive programs around the world, including the United States, Europe, Asia, the Middle East and South America.


  • Professor, International Institute for Management Development, Lausanne, Switzerland
  • Author, Left Brain, Right Stuff and The Halo Effect
  • Former finance and marketing manager, Hewlett-Packard
  • Former faculty member, Harvard Business School
  • Ph.D., Wharton School, University of Pennsylvania
  • MBA, University of California Los Angeles
  • BA, UC Santa Barbara


Left Brain, Right Stuff

How Leaders Make Winning Decisions

Phil Rosenzweig

Dozens of books have been published recently on the errors and biases that affect our judgments and choices. Drawing on cognitive science, their lessons are excellent for many kinds of decisions — consumer choice and financial investments, for example — but stop short of addressing many of the most important decisions we face in management, where we can actively influence outcomes and where competitive forces mean we have to outperform rivals.

As Phil Rosenzweig shows, drawing on examples from business, sports and politics, this sort of decision-making relies on mastering two very different abilities. First, the analytical problem-solving skills associated with the brain's left hemisphere; and second, what Tom Wolfe called 'the Right Stuff': the ability to take calculated risks. Bringing fresh and often surprising insights to topics including confidence and overconfidence, the uses and limits of decision models, leadership and authenticity, expert performance and deliberate practice, competitive bidding and new venture management, Left Brain, Right Stuff, the myth-busting follow-up to The Halo Effect, explains how to perform when making even the most difficult decisions.

Profile Books (1 Feb 2014)


Decide WiselyBusinessworld
Book ReviewMoneyLife
Left Brain, Right StuffThe Huffington Post
Book ReviewThe Wall Street Journal


“With compelling accounts and research results, Phil Rosenzweig takes us through the world of big, strategic decisions. They are thorny, complex, and risky, and he shows that they require analytic thinking, intuitive judgment, and personal confidence without certitude. Left Brain, Right Stuff delivers an invaluable framework for making good and timely decisions by all who sit in a leadership chair.”
—Michael Useem, director of the Wharton Leadership Center, University of Pennsylvania, and co-author of Boards That Lead

Left Brain, Right Stuff will help (force) you to rethink what you thought you knew about behavior and decision making. It will show you how to avoid the traps that have been set by some very popular (and dangerously erroneous) writings on the topic. This book will surprise you, it will challenge your (and your colleagues’) thinking in a very productive way, and it will be fun to read. Read it twice: once for the enjoyment of it, and once for pragmatic applications. It is certain to provoke the right kinds of discussions within your management team, and to raise your organization’s hit rate for effective decision making.”
—Adrian J. Slywotzky, partner, Oliver Wyman, co-author of The Profit Zone, and author of Demand

“No one thinks as clearly — and writes as clearly — as Phil Rosenzweig does about the diagnostic challenges of assessing the quality of business judgment and about the prescriptive challenges of improving it.”
—Philip E. Tetlock, Annenberg University Professor, University of Pennsylvania, author of Expert Political Judgment: How Good Is It? How Can We Know?

Left Brain, Right Stuff intrigued me on a number of levels. By parsing strategic situations, Rosenzweig convinces us that we control more than we think we do. When we believe in ourselves, we increase the probability of a great outcome. Then add in an understanding of ‘winner take all’ competition and the need to assess relative performance (not absolute performance), and my eyes were opened wide.”
—Joanna Barsh, director emeritus, McKinsey and Co.

“This fine book argues that the accepted tenets of behavioral economics are inadequate when dealing with strategic decisions in which the players can influence the outcome. The gripping stories neatly reveal the true complexity that is not captured in laboratory experiments, and put a needed reality check on the standard dogma of decision making. Essential reading.”
—David Spiegelhalter, Winton Professor for the Public Understanding of Risk, Cambridge University

The Halo Effect

... and the Eight Other Business Delusions That Deceive Managers

Phil Rosenzweig

Much of our business thinking is shaped by delusions — errors of logic and flawed judgments that distort our understanding of the real reasons for a company's performance. In a brilliant and unconventional book, Phil Rosenzweig unmasks the delusions that are commonly found in the corporate world. These delusions affect the business press and academic research, as well as many bestselling books that promise to reveal the secrets of success or the path to greatness. Such books claim to be based on rigorous thinking, but operate mainly at the level of storytelling. They provide comfort and inspiration, but deceive managers about the true nature of business success.

The most pervasive delusion is the Halo Effect. When a company's sales and profits are up, people often conclude that it has a brilliant strategy, a visionary leader, capable employees, and a superb corporate culture. When performance falters, they conclude that the strategy was wrong, the leader became arrogant, the people were complacent, and the culture was stagnant. In fact, little may have changed — company performance creates a Halo that shapes the way we perceive strategy, leadership, people, culture, and more.

Drawing on examples from leading companies including Cisco Systems, IBM, Nokia, and ABB, Rosenzweig shows how the Halo Effect is widespread, undermining the usefulness of business bestsellers from In Search of Excellence to Built to Last and Good to Great.

The Halo Effect replaces mistaken thinking with a sharper understanding of what drives business success and failure. The Halo Effect is a guide for the thinking manager, a way to detect errors in business research and to reach a clearer understanding of what drives business success and failure.

Skeptical, brilliant, iconoclastic, and mercifully free of business jargon, Rosenzweig's book is nevertheless dead serious, making his arguments about important issues in an unsparing and direct way that will appeal to a broad business audience. For managers who want to separate fact from fiction in the world of business, The Halo Effect is essential reading — witty, often funny, and sharply argued, it's an antidote to so much of the conventional thinking that clutters business bookshelves.

Pocket Books (6 Oct 2008)
Simon & Schuster Ltd; annotated edition edition (3 Feb 2007)


Phil tailors each presentation to the needs of his audience and is not limited to the topics we have listed below. These are subjects that have proven valuable to customers in the past and are meant only to suggest his range and interests. Please ask us about any subject that interests you; we are sure that we can accommodate you.

Nine Delusions That Confuse Business Thinking

  • The Halo Effect
    Many things we commonly claim drive company performance are simply attributions based on prior performance.
  • The Delusion of Correlation and Causality
    Two things may be correlated, but which causes which?
  • The Delusion of Single Explanations
    We tend to exaggerate the importance of any one factor in performance.
  • The Delusion of Connecting the Dots
    Looking for commonalities in successful companies doesn’t work.
  • The Delusion of Rigorous Research
    If the data aren't valid, the findings are doubtful.
  • The Delusion of Lasting Success
    Blueprints for lasting success are attractive but unrealistic.
  • The Delusion of Absolute Performance
    Company performance is relative, not absolute.
  • The Delusion of the Wrong End of the Stick
    We tend to confuse cause and effect.
  • The Delusion of Organizational Physics
    Company performance does not obey immutable laws of nature.


Towards Better Decision Making | Left Brain Right Stuff