Which of the following is NOT one of Porter’s Five Forces?

• A. Threat of new entrants
• B. Bargaining power of suppliers
• C. Threat of substitute products
• D. Economies of scale

Answer: (D)

Porter's Five Forces framework helps explain why some industries earn higher profitability by looking at five sources of competitive pressure. These are the threat of new entrants, the bargaining power of suppliers, the bargaining power of buyers, the threat of substitute products, and rivalry among existing competitors. Economies of scale describes cost advantages that come with producing at larger volumes; it affects cost structure and can influence barriers to entry, but it is not itself a separate competitive force. So it doesn’t belong to the five forces. The other terms map directly to the forces: new entrants, suppliers’ power, and substitutes are all standard forces shaping industry profitability.