"Competitive Strategy Techniques for Analyzing Industries and Competitors" by Michael E. Porter. The book provides a framework for understanding and analyzing industry structures and competitive dynamics. It focuses on five key forces that shape competition: rivalry among existing firms, the threat of new entrants, the threat of substitute products, the bargaining power of buyers, and the bargaining power of suppliers. Porter also examines how these forces can be influenced by firm-level actions and the evolution of an industry over time. He describes various generic strategies for firms to achieve a competitive advantage and provides insights into competitor analysis, industry evolution, and strategic decisions such as vertical integration, capacity expansion, and entry into new businesses.