What best describes the profitability mechanism in Porter’s Five Forces?

• A. Each force changes average industry profitability by creating systematic pressure on price and/or cost.
• B. Profitability is determined solely by the number of competitors.
• C. Profitability is fixed and unaffected by external forces.
• D. Only supplier power affects profitability.

Answer: (A)

Porter’s Five Forces shows that industry profitability arises from how multiple external pressures affect price and cost. Each force—the threat of new entrants, bargaining power of buyers, bargaining power of suppliers, threat of substitutes, and rivalry among existing firms—exerts a systematic pressure on either the price firms can charge or their costs, shaping the margins across the industry. That’s why this description is the best: profitability changes as these forces push on price and/or cost. For example, strong buyers can push prices down; powerful suppliers can raise input costs; substitutes can limit how high prices can go; new entrants increase competition; and fierce rivalry can erode margins. Profitability isn’t fixed or driven by a single factor, and it isn’t only about supplier power or the number of competitors.