“The essence of strategy is choosing what not to do.”
Source: What is strategy?, 1996, p. 70
Michael Eugene Porter is an American academic known for his theories on economics, business strategy, and social causes. He is the Bishop William Lawrence University Professor at Harvard Business School, and he was one of the founders of the consulting firm The Monitor Group .

“The essence of strategy is choosing what not to do.”
Source: What is strategy?, 1996, p. 70
Source: Competitive strategy, 1980, p. 301
Source: Competitive strategy, 1980, p. 157
2008 edition, p. 248
Competitive strategy, 1980
“The best CEOs I know are teachers, and at the core of what they teach is strategy.”
Michael Porter, "The CEO as strategist," in: Henry Mintzberg, Bruce W. Ahlstrand, and Joseph Lampel (eds.). Strategy bites back: It is a lot more, and less, than you ever imagined. Pearson Education, 2005. p. 45
“Strategy is about making choices, trade-offs; it's about deliberately choosing to be different.”
"What is strategy?," 1996
Context: There's a fundamental distinction between strategy and operational effectiveness. Strategy is about making choices, trade-offs; it's about deliberately choosing to be different. Operational effectiveness is about things that you really shouldn't have to make choices on; it's about what's good for everybody and about what every business should be doing.
“The essence of formulating strategy is relating a company to its environment.”
Source: Competitive strategy, 1980, p. 3
Competitive Advantage, 1985
Michael Porter, "The CEO as strategist," in: Henry Mintzberg, Bruce W. Ahlstrand, and Joseph Lampel (eds.). Strategy bites back: It is a lot more, and less, than you ever imagined. Pearson Education, 2005. p. 45
Source: Competitive strategy, 1980, p. 35