Editor’s Note:
In 1979,
Harvard Business Review
published “How Competitive Forces Shape Strategy”
by a young economist and associate professor,
Michael E. Porter. It was his first HBR article,
and it started a revolution in the strategy field. In
subsequent decades, Porter has brought his signature
economic rigor to the study of competitive
strategy for corporations, regions, nations,
and, more recently, health care and philanthropy.
“Porter’s five forces” have shaped a generation of
academic research and business practice. With
prodding and assistance from Harvard Business
School Professor Jan Rivkin and longtime colleague
Joan Magretta, Porter here reaffirms, updates,
and extends the classic work. He also addresses
common misunderstandings, provides
practical guidance for users of the framework,
and offers a deeper view of its implications for
strategy today.