Why do firms in most markets locate at or near the bottom of the long-run average cost curve?

• A. Because it yields the highest output
• B. Because the minimum point represents an efficient level of output
• C. Because it minimizes fixed costs
• D. Because it maximizes profits per unit

Answer: (B)

Minimizing costs per unit in the long run drives where firms choose to operate. The long-run average cost (LRAC) curve shows the lowest possible average cost for every level of output when a firm can adjust all inputs, including plant size. The bottom point of the LRAC is the efficient scale, where average cost is as low as it can be for that plant size. Operating at or near this point keeps costs per unit as low as possible, which helps a firm compete and earn profits. If a firm produces well above or below this level, average costs rise, giving a strong incentive to adjust size or output toward the minimum.