DSE Econ Ch1 完整報告:Basic Concepts in Economics

(Pearson Exploring Economics Book 1, Third Edition — Topic A 基本經濟概念)

Established 2026-08-28;完整報告整合 2026-08-29(取代舊版「課文+18題MCQ」拆解)。 Status: 課文骨架 + 18題課後MCQ + 10題Short Questions + Case Analysis Q1–Q4 全部跑完,統一採用「Knowledge Nodes + Relationship tested」格式;官方Chapter Summary 交叉確認無遺漏。

1. 知識骨架:七個學習目標如何連成一條鏈

核心因果鏈(A類,決定性機制)

1. 稀缺性與無限欲望(scarcity and choice 的起點)→ 資源有限、欲望無限,整個經濟學存在的前提
2. ↓ 因為資源有限,必須選擇(choice)— 第一個轉折node
3. ↓ 選擇必然產生代價 → 機會成本(opportunity cost)登場 — 本章最核心的node,後面幾乎所有目標都從這裡延伸
4. ↓ 機會成本不是固定值,會隨情境改變(資源可得性、時間點、可選方案變化)— 學生最常漏答「為什麼會變」的地方

從機會成本分出的兩個分支

• 5a. Free goods vs economic goods 的判準,本質是「機會成本是否為零」— 分類判準型node(二分類),不是鏈式因果
• 5b. 利息作為機會成本 — 資金用於當前消費/借出,就放棄了其他用途;利息反映資金機會成本。本章唯一「應用型」目標

獨立結構性node(非因果鏈,描述性模型)

• 6. Circular flow of economic activities(經濟活動循環圖)— 結構圖/系統關係圖,家庭、廠商、政府經商品市場與生產要素市場互相連結;像bio的「結構-功能協作圖」,筆記單獨一格處理

待確認(後續章節驗證):PPC生產可能性曲線是否在本冊出現 — Ch1 處理過的題目未見。

2. 課後MCQ 18題完整拆解(bilingual格式,無壓縮)

格式統一為 Knowledge Nodes(知識節點)→ Relationship Tested(考察關係)→ Answer;專業術語首次出現皆標「English term(中文術語)」。

Q1. Scarcity ___.

Knowledge Nodes(知識節點):

• Scarcity(稀缺性)
• Resources(資源)
• Wants(欲望)
• Quantity/availability of a good(物品的數量/可得性)

Relationship Tested(考察關係): Resources limited relative to wants(相對於欲望的資源有限)→ scarcity exists, regardless of the good's absolute quantity. Scarcity ≠ absolute physical shortage(絕對短缺)— it is quantity-available vs. quantity-desired(供應量對比欲望量)。

Answer: B

Q2. Which statement about scarcity is true?

Knowledge Nodes:

• Scarcity
• Economic development(經濟發展)
• Wealth / income(財富/收入)
• Developed vs. developing economies(發達vs發展中經濟)

Relationship Tested: Development↑ or wealth↑ does not disconnect a person/economy from scarcity — wants continue to exceed available resources at any income level. → Scarcity is universal(普遍性),not a poverty-specific problem。

Answer: D

Q3. Which explains the relationship between scarcity and choice?

Knowledge Nodes:

• Scarcity
• Choice(選擇)
• Limited resources(有限資源)
• Alternative uses of resources(資源的替代用途)

Relationship Tested: Scarcity → Choice(one direction only,單向)。 Resources cannot satisfy all wants → choices among alternative uses are forced。 Without scarcity, there is nothing to choose between。

Answer: C

Q4. All of the following incur opportunity cost EXCEPT:

Knowledge Nodes:

• Opportunity cost(機會成本)
• Forgone alternative(被放棄的選項)
• Sunk cost(沉沒成本)

Relationship Tested: (A)/(B)/(D) each connect a present choice to a genuine forgone alternative(leisure↔study, Disneyland↔Ocean Park, housing estate↔commercial complex)。 (C) connects instead to a separate node — money already spent and unrecoverable(tuition)— a sunk cost, not linked to any current forgone alternative。

Answer: C

Q5. Opportunity cost is measured by:

Knowledge Nodes:

• Opportunity cost
• Alternatives(替代選項)
• Highest-valued alternative forgone(價值最高的被放棄選項)

Relationship Tested: Choice → alternatives forgone → the measure isolates the SINGLE highest-valued one。 Not price paid, not total expenditure, not the sum of all alternatives。

Answer: A

Q6. David wins $0.3 million; preference ranking flat > car > watch; chooses the flat.

Knowledge Nodes:

• Choice
• Preference ranking(偏好排序)
• Opportunity cost
• Income source(收入來源)— turns out to be an unconnected node(無關node)

Relationship Tested: Choosing the flat forgoes both the car and the watch, but opportunity cost isolates only the higher-ranked of the two(car)。 The money's SOURCE(lottery)does not connect to this relationship — how the money was obtained does not alter the value-ranking of the alternatives。

Answer: A

Q7. Peter's coupon — Bubble Trap $100 > King of Knights $80 > Cat Empire $60; choosing Bubble Trap. Which event lowers the cost?

Knowledge Nodes:

• Opportunity cost
• Value of the forgone option(被放棄選項的價值)
• Usability / complementary requirement(可用性/配套條件,即console)
• Chosen-option's own condition — unconnected node(被選選項自身狀態,無關node)

Relationship Tested: Cost of Bubble Trap = value of King of Knights(the current highest-valued forgone option)。 This value depends on King of Knights actually being playable(needs a working console)— a broken console lowers its value → cost falls。 Cat Empire's value rising only matters if it overtakes King of Knights(which would raise, not lower, cost)。 Bubble Trap's own compatibility issue connects to the chosen option, not to cost。

Answer: D

Q8. Mr Lee's Shenzhen flat — which raises his cost of living there?

Knowledge Nodes:

• Opportunity cost of occupying property(自住的機會成本)
• Forgone rental income(放棄的租金收入)
• Forgone sale value(放棄的出售價值)
• Transfer-restriction policy(轉讓限制政策)

Relationship Tested: Occupying the flat forgoes renting it out — the node connected to an OCCUPANCY decision(自住決策)is rental income, not sale price(a separate, one-off liquidation decision,一次性變現決策)or a transfer restriction(which connects to the sale-value node, not rental)。

Answer: A

Q9. Paul — take 2 more subjects vs. self-financed exchange to Beijing. Which raises the cost of taking subjects?

Knowledge Nodes:

• Opportunity cost
• Value of the forgone alternative(exchange programme)
• New alternative entering(summer job,新選項進入)
• Chosen-option enjoyment — unconnected node

Relationship Tested: Cost of subjects = value of the exchange programme。 A rise in the exchange programme's own expense(fee, air ticket)reduces its net value as an alternative — lowers, not raises, cost。 A NEW alternative(summer job)valued higher than the exchange programme becomes the new highest-valued forgone option — raises cost。 Finding the subjects "boring" connects to the chosen option, not to cost。

Answer: D

Q10. Mr Chan's $5,000 phone — which raises the cost of keeping it?

Knowledge Nodes:

• Cost of owning(擁有成本,via resale value)
• Cost of using(使用成本,recurring service fee)
• New-phone retail price — a separate/unconnected market(另一個市場)

Relationship Tested: Cost of keeping = value of the forgone resale option, tied directly to THIS phone's resale price in the second-hand market(二手市場)。 Not the retail price of a new unit(different market), and not service fees(connects to using-cost, not owning-cost)。

Answer: B

Q11. Mr Zhao's already-purchased air ticket to Kazakhstan vs. high-speed train.

Knowledge Nodes:

• Sunk cost(ticket already paid,已付機票=沉沒成本)
• Value of the forgone alternative(train)
• Chosen-option's experienced value — unconnected node
• Non-money cost of executing the chosen option(執行被選選項的非金錢成本,waiting time)

Relationship Tested: Ticket price is already fixed and disconnected from later market-price changes。 A rise in train fare lowers the train's net value as an alternative — lowers, not raises, cost。 Waiting time from flight delays connects to a DIFFERENT node: a direct non-money cost of carrying out the chosen option, not routed through the forgone-alternative relationship at all。

Answer: D

Q12. Music group discovers no work permit — performing would be illegal. Effect on opportunity cost?

Knowledge Nodes:

• Opportunity cost
• Legal-risk cost(法律風險成本)
• Sunk transportation cost — unconnected to this new information(交通費沉沒成本,與新資訊無關)

Relationship Tested: Illegality connects to a new node — potential legal penalties(潛在法律罰則)— a genuine added cost from this specific discovery, separate from the(irrelevant either way)sunk transport expense。

Answer: D

Q13. An economic good MUST be a good:

Knowledge Nodes:

• Quantity vs. wants(數量對比欲望)
• Production cost(生產成本,can be zero even for an economic good)
• Market price(市場價格,not necessarily positive)
• Market sale(市場出售,not necessarily required)

Relationship Tested: Only "quantity insufficient relative to wants" connects necessarily to "economic good." Production cost is separate — a naturally-occurring good can have zero production cost yet still require an obtaining/catching cost(取得/捕捉成本)。 Positive price and market sale are also not necessary — a good can be transferred free of charge with the cost borne by someone else。

Answer: A

Q14. Which are economic goods? (1) free-of-charge housing right (2) right to consume in advance (3) better-view hotel room right.

Knowledge Nodes:

• Free of charge vs. free good(免費 vs. 免費物品,a one-directional relationship,單向關係)
• Scarce right/privilege(稀缺權利/特權)
• Interest(利息,compensation for earlier availability)

Relationship Tested: "Free of charge to this recipient" does not disconnect a good from scarcity — the underlying resource stays scarce even when a specific transaction is zero-priced。 Early consumption connects to the same scarce-privilege node as interest。 All three connect to "quantity insufficient relative to wants."

Answer: D

Q15. If a good is a "free good", we would expect:

Knowledge Nodes:

• Quantity vs. wants at zero price(零價格下數量對比欲望)
• Free of charge — a downstream, distinct node(下游、獨立的node)

Relationship Tested: Defining relationship: quantity-available exceeds quantity-wanted AT ZERO PRICE。 Not "unlimited supply"(overstates it), not "government distributes it free"(connects to the free-of-charge node, not the free-good node — same one-directional relationship as Q14)。

Answer: D

Q16. A free good must be free-of-charge because:

Knowledge Nodes:

• Wants satisfied(欲望已滿足)
• Production cost — non-causal here(此處非因果關係)

Relationship Tested: Stated link: "quantity sufficient to satisfy all wants" → "no one willing to pay" → "free of charge." "Gift of nature"(大自然的贈予)does not connect to this relationship(nature-given goods can still be economic goods)。 "No production"(冇生產)is plausible-sounding but not the actual stated link。

Answer: B

Q17. Which statement is correct?

Knowledge Nodes:

• Production(生產)
• Consumption(消費)
• Purpose of the activity(活動目的,self-satisfaction vs. service-to-others)
• Output creation — does not alone determine classification(單憑「有產出」不足以判斷分類)

Relationship Tested: Production transforms resources into goods/services; Consumption satisfies wants。 Classification is NOT simply "was an output created" — Mary's drawing creates an output yet connects to Consumption because its purpose is her own stress relief。 Peter's cooking connects to Production because it serves customers via an exchange-oriented activity(以交換為導向的活動)。

Answer: D

Q18. Circular flow statements — (1) firms as production units (2) households provide factor services (3) all people can be producer + consumer.

Knowledge Nodes:

• Firms(廠商)
• Households(家庭)
• Factor market(生產要素市場)
• Factor services(生產要素服務)
• Dual role(雙重身分)

Relationship Tested: (1)/(2) map directly onto the circular-flow diagram's defined roles。 (3) connects to the observation that a household member simultaneously supplies factor services(production-side)and spends income(consumption-side)— both roles coexist in one person。

Answer: D

統計:15/18 是主檔案已知規則的直接應用;Q11、Q17 是確認的新node;Q8 是課文未明言的真實世界延伸(imputed rent慣例,屬領域知識補缺,與「新經濟邏輯」分開標記)。

3. Short Questions Q1–Q10

Q1 — The basic concept of economics is scarcity. Does this mean that economics is useless in rich countries like the US?

Knowledge Nodes: Scarcity(稀缺性), Resources(資源), Wants(欲望), Economic choice(經濟選擇), Rich/developed economies(富裕/發達經濟)

Relationship tested: Richness / high income(富裕/高收入) does not eliminate scarcity — resources remain limited relative to wants → choices still necessary → economic problem remains relevant. 核心關係:Resources limited relative to wants → scarcity → choice;「rich country」只改變available resources的水平,沒有消除scarcity。

Answer: No. Even rich countries face scarcity because resources are limited while human wants are unlimited, so they still have to make choices.

Q2(a) — Opportunity cost of using the land to build a commercial complex?(Swimming pool = $100m; Commercial complex = $90m; Residential estate = $70m)

Relationship tested: Choose commercial complex → forgo swimming pool & residential estate → highest-valued forgone alternative = swimming pool($100m)。 Answer: $100 million — the swimming pool is the highest-valued alternative forgone.

Q2(b) — Opportunity cost of using the land to build a swimming pool?

Relationship tested: Choose swimming pool → forgo commercial complex & residential estate → highest-valued forgone = commercial complex($90m)。 Answer: $90 million — the commercial complex is the highest-valued alternative forgone.

Q2(c) — Oil suddenly discovered under the land. How does this affect the opportunity cost of building a swimming pool?

Relationship tested: Oil discovered → land gains an additional valuable alternative use(oil extraction)→ value of the forgone alternative ↑ → OC of swimming pool ↑。 核心鏈:Oil discovery → value of alternative use of land ↑ → OC of swimming pool ↑ — 題目不是在考「oil is valuable」,而是在考 change in value of a forgone alternative → change in OC。

Answer: The opportunity cost will increase, because extracting oil becomes a more valuable alternative use of the land; by using the land for a swimming pool, this higher-valued alternative is forgone.

💭 小提示:Q2整組浮現一條清楚的知識關係:Choice → alternatives forgone → value of highest-valued forgone alternative → OC,而Q2(c)再加 change in alternative's value → change in OC。這條關係是本單元後續大量題目的骨架,原樣保存。

Q3(a) — Judy: car's safety rating very low. How does this affect her cost of choosing the luxury watch?

Knowledge Nodes: OC, Value of forgone alternative, Ranking of alternatives(選項排序), Highest-valued forgone option

Relationship tested: Car(3rd priority) already ranked below the diamond ring(2nd priority,current highest-valued forgone option)。Car further losing value does not change which option holds that rank → no effect on cost。 核心關係:value change of a lower-ranked option, moving further away from overtaking → no effect on cost。

Answer: No effect — the car, already ranked below the diamond ring, becoming less desirable does not change which item is the highest-valued forgone option.

Q3(b) — The diamond ring Judy wants is out of stock. How does this affect the cost?

Relationship tested: Diamond ring — currently the highest-valued forgone option — becomes entirely unavailable, removed from the choice set altogether(不是mere value decrease)。Next-highest available option(car)becomes the new highest-valued forgone option。 核心鏈:highest-valued forgone option becomes unavailable → removed from choice set → next-highest AVAILABLE option takes its place。

Answer: The cost changes from the diamond ring to the car — the ring is no longer an available alternative; among remaining available options, the car is now the highest-valued forgone alternative.

Q3(c) — The market value of the luxury watch increases rapidly. How does this affect the cost?

Relationship tested: The watch is the chosen option. A change in the chosen option's own value does not connect to cost — cost is determined solely by the forgone alternative's value。

Answer: No effect — cost depends only on the highest-valued forgone alternative(diamond ring), unaffected by the watch's own value rising.

💭 小提示:Q3三小題剛好各自對應三種唔同嘅node狀態變化——(a)已知低排名選項再跌值(冇影響)、(b)最高值forgone選項完全消失(要重新搵接替者)、(c)被選中選項本身變化(冇影響)。(b)「選項完全從choice set移除」同MC入面「選項只係跌值」係唔同機制:一個係「value→0但選項仍存在」,一個係「選項物理上唔存在」。呢個分野幾時會產生實質分別,繼續觀察。

Q4(a) — Nam Sang Wai: if residential development is allowed, will the cost of developing necessarily remain unchanged if property prices fall significantly?

Relationship tested: Property price is a determinant of the chosen option's value(residential development),not the forgone alternative's(wetland preservation)value。 核心:必要性命題(necessarily)— 被選選項價值下跌≠成本下跌。

Answer: Yes, the cost will remain unchanged — falling property prices affect the value received from development itself (chosen option), not the value of preserving the wetland (forgone alternative).

Q4(b) — Will the cost necessarily remain unchanged if a fire destroys the wetland ecosystem?

Relationship tested: Fire destroys the very source of value in the forgone alternative(wetland ecosystem that attracts bird-watchers, cyclists, photographers)→ forgone alternative's value ↓ → OC ↓。 核心鏈:event destroys forgone alternative's underlying value source → forgone value ↓ → OC ↓。

Answer: No — it will decrease. The fire destroys the source of value in the forgone alternative (preserving the land), so the opportunity cost of developing falls.

💭 小提示:Q4(a)/(b)係一組刻意設計嘅對照——(a)改變緊被選中選項嘅價值(property price屬「起樓」呢個選擇嘅回報),(b)改變緊被放棄選項嘅價值(火燒毀濕地,直接打擊「保育」呢個forgone alternative)。表面都係問「起樓成本會唔會變」,實際考緊完全相反嘅兩個node——一問兩考、方向相反,同MC Q9(Paul)結構相似。

Q5 — Doctor Chan says his haircut costs more than the taxi driver's, same time & money at same salon. Who is right?

Knowledge Nodes: Full cost(全部成本), Money cost(金錢成本), Non-money cost(非金錢成本,time cost), Income forgone(放棄的收入), Individual variation in cost(個別差異)

Relationship tested: Same money cost + same time duration does NOT imply same full cost — non-money cost measured by income forgone during that time, which differs across earning levels。

Answer: Doctor Chan is right — cost includes non-money cost measured by income forgone; a doctor likely earns more per hour, so his full cost of the haircut is higher despite identical money cost and time.

Q6 — "There is no such thing as a free lunch." Do you agree?

Relationship tested: "Free of charge"(對接收者零價格)≠ zero cost in the economic sense — resources have alternative uses, so a genuine OC almost always exists somewhere (borne by recipient or third party); cost is truly zero only when no alternative use of the resource exists at all。

Answer: Agree — resources are scarce and have alternative uses; almost every activity involves an OC somewhere, even if borne by a third party. Cost is only zero when no alternative use exists.

Q7(a) — John downloads an infringed ebook free; Jane pays $5 legitimately. "John's ebook is a free good." Do you agree?

Knowledge Nodes: Free good(免費物品), Free of charge(免費), Economic good(經濟物品), Willingness to pay(支付意願)

Relationship tested: An item obtained free of charge by one person does not make it a free good — the underlying good remains scarce/economic if people (Jane) are willing to pay for it in the market。

Answer: Disagree — the ebook is an economic good; Jane's willingness to pay $5 shows it has value and cannot satisfy everyone's wants free. John's infringement shifts the cost elsewhere (e.g. lost revenue to the copyright holder), it does not change the book's scarce nature.

Q7(b) — "John's cost of obtaining the ebook must be lower than Jane's." Do you agree?

Relationship tested: John's money cost($0)< Jane's($5),but full cost includes risk-based non-money components(legal penalty, malware, unreliable quality)that Jane's legitimate purchase avoids。 核心:necessity claim(「must」)— 一個反例即可反駁。

Answer: Disagree — although John's money cost is $0, his full cost is not necessarily lower: an infringed copy carries risk-based non-money costs (legal penalties, malware, lower reliability) that the $5 legitimate purchase avoids.

Q8 — Ocean Park gives 10,000 free tickets to students. Are the free tickets a free good?

Relationship tested: A limited quantity (10,000, insufficient for all students who might want to visit) given away free by a third party remains an economic good — same one-directional relationship as Q7(a)。

Answer: No — tickets are limited in quantity and the park incurs real operating costs; giving away this limited quantity free of charge means Ocean Park bears the cost instead of the recipient.

💭 小提示:Q7(a)、Q8同MC Q14/Q15其實係同一條node relationship(Free good ⟹ Free of charge,不可逆)不斷變裝出現——盜版書、免費門票、政府派發,表面情境完全不同,拆解出嚟嘅node同relationship一模一樣。呢種「換情境唔換邏輯」嘅高頻出現,暗示呢條關係係出題人特別鍾意用嚟出短答題嘅骨架。

Q9 — What is the meaning of interest for borrowers and lenders, respectively?

Knowledge Nodes: Interest(利息), Borrower(借方), Lender(貸方), Earlier availability(提早獲得資源), Deferred consumption(延後消費)

Relationship tested: Interest has a dual definition depending on perspective — the same single payment is simultaneously a "cost" (borrower) and a "compensation" (lender)。

Answer: For a borrower, interest is the cost of obtaining earlier availability of resources — the price paid to access resources now rather than later. For a lender, interest is the compensation for deferring consumption — the reward for giving up present use in exchange for greater future consumption.

Q10 — "Interest does not exist when there is no money." Do you agree?

Relationship tested: Interest is rooted in the present-vs-future consumption trade-off caused by scarcity, not in the existence of money — money is a medium for expressing interest, not a precondition。 核心:barter經濟下利息照樣存在(借一隻雞還雞+蛋,蛋=利息)。

Answer: Disagree — interest exists even in a barter economy (e.g. borrowing a hen and repaying a hen plus extra eggs); it is rooted in scarcity and deferred consumption, not money.

4. Case Analysis Q1–Q4

Q1 — What is Leader Lee's cost of continuing to develop nuclear weapons?

Relationship tested: Direct application of the two-step procedure — delete the chosen option (1st priority), find the highest value among what remains (2nd > 3rd)。

Answer: Giving up the nuclear weapons plan and trading with the Starfruit Empire (the 2nd priority — highest-valued option among those not chosen).

Q2 — Explain how the events in Source A affect Leader Lee's cost of continuing nuclear development.

Relationship tested: Source A contains two separate events testing two different relationships: (i) Starfruit's increased trade benefits raise the value of the option that is ALREADY the highest-valued forgone alternative → cost rises; (ii) worsening relationship with Apple Empire's President Di lowers the 3rd-priority option — not the highest-valued forgone option, already ranked below Starfruit → no effect on cost。

Answer: The increased trade benefits from Starfruit raise Lee's cost (already his highest-valued forgone option). The worsening relationship with President Di only affects the lower-ranked Apple Empire option and has no effect on his current cost.

Q3 — Explain why Leader Lee's statement in Source B is NOT correct.

Knowledge Nodes: Sunk cost(沉沒成本), Free good definition, Cost of producing, OC of resources used, Scarcity

Relationship tested: The statement contains two separate errors: (i) the $10 billion already spent is treated as relevant to the current cost — but it is a sunk cost, unrecoverable either way; (ii) "producing unlimited nuclear weapons = free good at zero cost" misapplies the free-good definition — producing them still consumes scarce resources with alternative uses (e.g. addressing the famine), so cost of producing is not zero; quantity available does not connect to whether the resources used remain scarce。

Answer: Incorrect for two reasons. First, the $10 billion spent is a sunk cost — unrecoverable regardless of the current decision, so it should not count toward the cost of continuing or abandoning the plan now. Second, nuclear weapons would not become a free good even with unlimited production capacity — producing them still requires scarce resources (money, materials, labour) with alternative uses (e.g. relieving the famine); a free good requires zero cost of production, which does not hold here.

Q4 — Refer to Source C. Does the deal between Leader Lee and President Zhang involve interest?

Relationship tested: A direct instance of interest existing without money — the extra item (wild ginseng) beyond the exact repayment amount constitutes interest paid in kind。

Answer: Yes — President Zhang lends 1,000 tons of food and receives back 1,000 tons plus a 1,000-year-old wild ginseng after one year; the extra ginseng is the interest, compensation for deferring his own consumption/use of the food.

💭 小提示:成個Case analysis將單元內幾條分散嘅node壓縮埋一齊考——Q1純練程序,Q2考「一個source入面兩件事分別接落唔同node」,Q3最豐富(兩個獨立錯誤sunk cost誤用+free good誤用疊喺同一句對白),Q4返去interest。留意Q3個「free good」錯誤同Q7/Q8個one-directional relationship表面好似,但切入點唔同:Q7/Q8考「免費俾邊個」,Q3考「生產本身有冇消耗稀缺資源」——同一node,兩種獨立測試切入面,值得留意會唔會有第三種。

5. 選擇性小提示匯總(本單元真正值得跨題比較的邏輯關係)

1. OC的完整關係鏈(Q2組):Choice → alternatives forgone → value of highest-valued forgone → OC;以及 change in alternative's value → change in OC。這是全單元最高頻骨架。
2. 三種node狀態變化(Q3組):低排名選項跌值(無影響)/最高值選項移除(換接替者)/被選選項自身變化(無影響)——(b)與「跌值」是不同機制。
3. 一問兩考、方向相反(Q4組、MC Q9):chosen option價值變化vs forgone option價值變化,表面問題相同。
4. Free good ⟹ Free of charge 不可逆關係:Q7(a)/Q8/MC Q14/Q15四次變裝出現,是短答題最愛骨架。
5. free good node的兩個測試切入面:「免費俾邊個」(Q7/Q8)vs「生產是否消耗稀缺資源」(Case Q3)。
6. 新node(課文未明言):
   • Q11:被選選項自身的直接執行成本(等待時間)可以推高full cost,不經forgone機制——與「被選選項價值不影響成本」那條rule並行,兩條通道要分清楚。
   • Q17:生產vs消費是目的判準(purpose-based),不是「有沒有產出」(Mary畫畫=消費)。
7. 延伸(需外部慣例):Q8自住機會成本=放棄的租金收入(imputed rent),課文無明言。

6. Econ 特有的node形態(對比Chem/Bio,2026-08-29確認)

• node形狀:Econ Ch1的node多屬「規則+歸屬判斷」型 — 題目給一個事件,要判斷佢接落邊個node(chosen option / forgone option / sunk cost / money cost / non-money cost),唔似Chem嘅九層因果鏈、亦唔似Bio嘅結構-功能概念簇。
• 主機制(18題MC實證):attribution(歸屬判斷)— 某個改變屬於被選選項定放棄選項、金錢定非金錢成本、擁有定使用成本、沉沒定當前可選資源;必要vs充分條件判斷。Q4/Q6/Q9/Q10/Q11/Q12/Q13/Q15/Q16/Q17。
• 次要:表面定義措辭陷阱(Q1/Q5/Q13)、因果方向倒轉(Q2/Q3)。
• 待驗證(印象式判斷):圖形陷阱(沿曲線移動vs曲線平移)同aggregation scope陷阱(個體vs整體)——Ch1冇供需圖,要等後續單元先有證據。
• 修正後效果好嘅兩個具體點:① 已知規則只引用、新node先完整展開(避免每次重推已知定義);② 純node+relationship描述,唔預設trap type/cognitive layer分類(等證據夠先歸納,唔過早定型)。

7. 12-Node 邏輯關係圖(Logic Map of the 12 Tested Nodes)

MCQ 18題速覽表對應嘅12個測試node(見第2節),唔係平行獨立嘅知識點,而係一棵有依賴方向的知識樹:一條因果骨幹(Causal Backbone)+ 三個功能家族(Functional Families)。

第一層:因果骨幹(Causal Backbone,因果骨幹)— 單向、不可逆

無限欲望 + 有限資源 → 稀缺性(Scarcity,1:相對/普遍) → 選擇(Choice,2) → 機會成本(Opportunity Cost,3:定義+兩步程序)

依賴方向係 1→2→3,冇得跳步,亦冇得掉轉。呢條骨幹嘅「單向性」本身就係考點:Q2(B)掉轉因果、Q3(A)逆邏輯,全部係喺度測試你知唔知呢條鏈係不可逆嘅。

第二層:機會成本規則家族(Opportunity Cost Rule Family,OC規則族)— 全部依附喺node 3

呢個家族最大,佔12行入面7行(Q4、Q7、Q8、Q9、Q10、Q11、Q12),全部回答緊同一個問題:「邊個係被放棄嘅選項(forgone alternative)?乜嘢事件會改變佢?」——只係每個node負責唔同嘅歸屬項(attribution slot,歸屬槫位):

呢個家族嘅存在解釋咗點解18題MC主機制係attribution(歸屬判斷)——題目畀一個事件,全部係問「呢件事接落邊個歸屬項」:被選定放棄?金錢定非金錢?擁有定使用?沉沒定當前可選?

第三層:分類家族(Classification Family,分類族)— 由稀缺性直接派生,唔經機會成本

• Q13–16 物品分類(Goods Classification):稀缺性應用喺「物品」→ economic good(經濟物品) vs free good(免費物品);核心係單向關係 Free good ⟹ Free of charge(免費物品必然免費,但反過來不成立)
• Q17 活動分類(Activity Classification):目的判準(Purpose-based Test) → production(生產) vs consumption(消費)

同骨幹嘅關係要分清:分類家族係稀缺性嘅「應用面」,唔係機會成本嘅延伸。所以佢哋嘅測試切入面同OC家族完全唔同——OC家族考「事件接邊個歸屬項」,分類家族考「定義判定」+單向關係有冇被掉轉(Q15(C)免費派發=混淆咗兩層)。

第四層:結構整合模塊(Structural Integration Module,結構整合)— 唯一組裝型node

• Q18 circular flow(循環流程圖):將前面所有node嘅主體(households家庭/firms廠商)、生產(17)、交換、消費砌成一張系統圖。佢唔依附喺骨幹任何一環,係獨立模塊,所以考試傾向單獨考佢(Ch1冇證據佢會同OC家族交叉,等後續單元驗證)。

隱藏關係:利息(Interest)其實係骨幹嘅「時間維度」延伸

短答Q9/Q10嘅利息,嚴格嚟講係機會成本應用喺時間維度:提早獲得資源(earlier availability)=付出代價(借方borrower),延後消費(deferred consumption)=獲得補償(貸方lender),根源都係稀缺性逼你喺「而家vs未來」之間取捨。佢接住骨幹,但Ch1嘅MC冇單獨出題,只喺短答出現。

一句總結:12個node嘅邏輯結構 = 一條單向因果骨幹(1→2→3)、一個最大嘅機會成本規則家族(node 3下面7個歸屬項)、兩個稀缺性嘅分類應用面(Q13-16/Q17)、一個獨立結構整合模塊(Q18)。理解咗呢個關係圖,睇題目嘅第一反應唔應該係「呢題邊個node」,而係「呢件事接落邊個歸屬項」——後者先係出題人真正考緊嘅嘢。

Next Step

Unit 2 開跑前,先等Ch1上課效果反饋。開跑時驗證:attribution機制會否持續主導、會否出現第三種free good切入面、以及圖形/aggregation陷阱嘅首批證據;同埋驗證12-node關係圖入面嘅四層結構(因果骨幹/OC規則族/分類族/結構整合)喺Unit 2會唔會出現新嘅家族形態。

校本教材(TLHK S4 Economics)相關內容獨立存放於 dse-econ-ch1-tlhk-schoolbased.md,不與本檔(Pearson-based)混合,兩檔互相標記跨來源確認/新增node。 __