The output level at which a firm's average total costs are minimized is commonly referred to as the...

• A. Break-even point
• B. Efficient scale of production
• C. Shutdown point
• D. Profit-maximizing output

Answer: (B)

Efficient scale of production is the output level where average total cost is minimized. ATC, which is total cost divided by the quantity produced, typically falls as fixed costs are spread over more units and then rises due to diminishing returns, forming a U-shaped curve. The bottom of this curve—the point where ATC is lowest—occurs when marginal cost equals average total cost. In the long run, the output level that minimizes long-run average total cost is called the efficient scale of production. This differs from break-even (revenue equals costs), the shutdown point (price relative to average variable cost), and profit-maximizing output (where marginal revenue equals marginal cost).