Firms, costs and market structures
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| marginal cost/ˈmɑːdʒɪnl kɒst/ | 边际成本 | biān jì chéng běn |
| contestability/kənˌtestəˈbɪlɪti/ | 可竞争性 | kě jìng zhēng xìng |
A decision you can investigate
- A firm can sell more only by reducing its price.
- Extra sales add revenue, but may also reduce revenue on units already sold.
一个你可以调查的决策
- 企业只有通过降低价格才能销售更多产品。
- 额外销售会增加收入，但也可能降低已售出单位产品的收入。
Build the explanation
- Average cost is total cost divided by output; marginal cost 边际成本 is the change in total cost for one more unit.
- In the standard model, a profit-maximising firm chooses output where MR = MC with the appropriate rising MC condition.
构建解释
- 平均成本是总成本除以产量；边际成本 边际成本是指多生产一单位产品所引起的总成本变动。
- 在标准模型中，追求利润最大化的企业会选择边际收益等于边际成本（MR = MC）且符合边际成本递增条件的产量水平。
Match the terms to their precise meanings.
Use these definitions in the particular context of Firms, costs and market structures.
Work through the evidence
- At Q = 100, total revenue is 1,000 and total cost is 800, giving profit 200. At Q = 101, revenue is 1,006 and cost is 809.
- The extra unit adds MR = 6 and MC = 9, so profit falls by 3; expansion is not justified by revenue alone.
梳理证据
- 在 Q = 100 时，总收益为 1,000，总成本为 800，由此获得利润 200。在 Q = 101 时，收益为 1,006，成本为 809。
- 额外增加的单位带来的边际收益 MR = 6，边际成本 MC = 9，因此利润减少了 3；仅凭收益无法证明扩张的合理性。
Should the firm add the 101st unit under these figures?
At Q = 100, total revenue is 1,000 and total cost is 800, giving profit 200. At Q = 101, revenue is 1,006 and cost is 809. The extra unit adds MR = 6 and MC = 9, so profit falls by 3; expansion is not justified by revenue alone.
Test the limits
- Market concentration does not prove collusion. Contestability 可竞争性 depends on entry and exit barriers, including sunk costs.
- Separate short-run shutdown decisions from long-run exit and distinguish profit from cash flow.
测试极限
- 市场集中度高并不等同于存在串谋。可竞争性 可竞争性取决于进入和退出壁垒，包括沉没成本。
- 将短期停产决策与长期退出决策区分开来，并明确区分利润与现金流。
Which caution belongs to this particular task?
Market concentration does not prove collusion. Contestability depends on entry and exit barriers, including sunk costs. Separate short-run shutdown decisions from long-run exit and distinguish profit from cash flow.
The explanation in this lesson makes a conditional claim; relevant context and evidence still matter.
Separate short-run shutdown decisions from long-run exit and distinguish profit from cash flow.
Apply and explain your answer
- Should the firm add the 101st unit under these figures?
- No: marginal cost exceeds marginal revenue, reducing profit.
应用并解释你的答案
- 根据这些数值，企业是否应该生产第 101 个单位？
- 不应该：因为边际成本超过了边际收益，导致利润下降。
Choose the two statements supported by this lesson.
The concept and worked evidence support these claims; the stated limits rule out the universal shortcut.
Use the terms precisely
- marginal cost: The increase in total cost from one additional unit.
- contestability: The extent to which potential entry disciplines existing firms.
精确使用术语
- 边际成本：每多生产一单位产品所增加的总成本。
- 可竞争性：潜在进入者对现有企业产生约束的程度。
At Q = 100, total revenue is 1,000 and total cost is 800, giving profit 200. At Q = 101, revenue is 1,006 and cost is 809. The extra unit adds MR = 6 and MC = 9, so profit falls by 3; expansion is not justified by revenue alone.
Market concentration does not prove collusion. Contestability depends on entry and exit barriers, including sunk costs. Separate short-run shutdown decisions from long-run exit and distinguish profit from cash flow.
Average cost is total cost divided by output; marginal cost is the change in total cost for one more unit.
在 Q = 100 时，总收益为 1,000，总成本为 800，由此获得利润 200。在 Q = 101 时，收益为 1,006，成本为 809。额外增加的单位带来的边际收益 MR = 6，边际成本 MC = 9，因此利润减少了 3；仅凭收益无法证明扩张的合理性。
市场集中度高并不等同于存在串谋。可竞争性取决于进入和退出壁垒，包括沉没成本。将短期停产决策与长期退出决策区分开来，并明确区分利润与现金流。
平均成本是总成本除以产量；边际成本是指多生产一单位产品所引起的总成本变动。