差別化競争と過剰生産能力
導入済み| English | 意味 |
|---|---|
| excess capacity/ekˈses kəˈpæsɪti/ | 過剰生産能力 |
| product differentiation/ˈprɒdʌkt ˌdɪfəˌrenʃɪˈeɪʃn/ | 製品差別化 |
A decision you can investigate
- Several cafes offer different drinks, packaging and delivery choices. Customers may pay more for a particular variety, but new rivals can enter.
- Many firms can coexist with some price-setting ability.
Build the explanation
- Monopolistic competition combines many firms and relatively open entry with differentiated products. Each firm faces downward-sloping demand for its own variety and has limited market power; close substitutes constrain it. Physical differentiation changes features, marketing differentiation uses advertising/packaging, and distribution differentiation changes access through shops, online or telephone ordering. Distinguish useful quality/access changes from unsupported claims.
- In the short run a firm chooses the feasible profit maximum where rising MC crosses MR and reads price from AR/demand; it can earn economic profit or losses. With entry and sufficient substitutability, positive profits attract new varieties and reduce each incumbent’s demand. In the standard long-run tangency model AR touches AC at the MR=MC output, giving normal economic profit. Output lies below the minimum-AC scale: excess capacity 过剩产能 and P>MC imply static productive/allocative inefficiency in the simple benchmark, alongside possible benefits of variety.
Work through the evidence
- Use a fictional firm with TC=16+4Q+Q², MC=4+2Q and short-run demand P=20−Q, MR=20−2Q. Profit maximization gives20−2Q=4+2Q, so Q4, P16, TR64, TC48 and profit16. In this particular short-run case Q4 also minimizes AC; that coincidence is not a universal short-run result.
- A separate long-run entry-adjusted demand is P=a−Q, where a=4+4√8≈15.3137. Its equilibrium Q=√8≈2.8284 gives price4+3√8≈12.4853 and AC the same, so economic profit0. MC=4+2√8≈9.6569, below price by√8. AC is minimized at Q4 with value12, so excess capacity is4−√8≈1.1716. The AR/AC tangency is a whole equilibrium condition, not just any crossing of the two curves.
本ケースにおける短期の経済利益はいくらか？
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収益64から経済的原価48を引くと16となる。
哪一个是分销差异化？
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分销关注的是消费者如何获取产品。
垄断竞争中的零经济利润证明了配置效率。
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价格可能等于 AC 但高于 MC；外部性和产品多样性也需要评估。
Test the limits
- For the long-run numerical comparison, assume the stated cost curve represents attainable costs and no alternative plant gives a lower cost. Normal profit is compatible with a markup over marginal cost because price also covers fixed and normal-return costs. The standard entry result needs open entry, demand redistribution and stable relevant costs; branding, strategic barriers or changing input prices can prevent it. Do not confuse monopolistic competition with monopoly or assume that every advertised product meets the model.
- Excess capacity refers to the minimum-AC benchmark, not necessarily physically idle seats at every moment. Consumers may value differentiated products enough to prefer variety over a single standardized low-cost output. Advertising can inform or create misleading preferences; distribution can improve accessibility or create exclusion. Assess price, quality, information, innovation and variety, with social externalities handled separately from the private P/MC comparison.
在长期情况下，哪种关系成立？
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相切点覆盖了 Q√8 处的经济成本，位于最小平均成本刻度4之下。
Apply and explain your answer
- Why can long-run economic profit be zero while price exceeds MC?
- Price equals AC, covering fixed costs and normal returns, but AC exceeds marginal cost at the lower-output tangency. Zero economic profit does not require P=MC.
用語とそれぞれの意味を結びつけよ。
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各用語を、その明示された経済的関係に用いること。
Use the terms precisely
- product differentiation 产品差异化: Differences in features, marketing or distribution that make customers distinguish firms’ products.
- excess capacity: Output below the minimum-average-cost scale in the stated long-run model, not necessarily a direct measure of physically idle equipment.
Use a fictional firm with TC=16+4Q+Q², MC=4+2Q and short-run demand P=20−Q, MR=20−2Q. Profit maximization gives20−2Q=4+2Q, so Q4, P16, TR64, TC48 and profit16. In this particular short-run case Q4 also minimizes AC; that coincidence is not a universal short-run result. A separate long-run entry-adjusted demand is P=a−Q, where a=4+4√8≈15.3137. Its equilibrium Q=√8≈2.8284 gives price4+3√8≈12.4853 and AC the same, so economic profit0. MC=4+2√8≈9.6569, below price by√8. AC is minimized at Q4 with value12, so excess capacity is4−√8≈1.1716. The AR/AC tangency is a whole equilibrium condition, not just any crossing of the two curves.
For the long-run numerical comparison, assume the stated cost curve represents attainable costs and no alternative plant gives a lower cost. Normal profit is compatible with a markup over marginal cost because price also covers fixed and normal-return costs. The standard entry result needs open entry, demand redistribution and stable relevant costs; branding, strategic barriers or changing input prices can prevent it. Do not confuse monopolistic competition with monopoly or assume that every advertised product meets the model. Excess capacity refers to the minimum-AC benchmark, not necessarily physically idle seats at every moment. Consumers may value differentiated products enough to prefer variety over a single standardized low-cost output. Advertising can inform or create misleading preferences; distribution can improve accessibility or create exclusion. Assess price, quality, information, innovation and variety, with social externalities handled separately from the private P/MC comparison.
Monopolistic competition combines many firms and relatively open entry with differentiated products. Each firm faces downward-sloping demand for its own variety and has limited market power; close substitutes constrain it. Physical differentiation changes features, marketing differentiation uses advertising/packaging, and distribution differentiation changes access through shops, online or telephone ordering. Distinguish useful quality/access changes from unsupported claims.