The Question Vault

Every element in this section has a direct mark consequence. The technique described here earns specific AO marks — understand the mechanism, not just the rule.

#PEARSON VERBATIM — EXACT LANGUAGE, SERIES CITED

The following quotations are verbatim from Pearson materials. These exact words appear in mark schemes and examiner reports. Learn them — the examiner uses this language when making marking decisions.

"NB Level 3 response requires a diagram." — Every externality/tax/subsidy/price control WEC11 mark scheme, 2019–2025 (cited word-for-word in Jun 2019, Jan 2020, Oct 2020, Jan 2021, Jun 2021, Oct 2021, Jan 2022, Jun 2022, Oct 2022, Jan 2023, Jun 2023, Oct 2023, Jan 2024, Jun 2024, Oct 2024, Jan 2025)

"NB Do not reward externalities diagrams." — Jun 2024 WEC11 mark scheme (subsidy question, confirmed verbatim)

"Chains of reasoning in terms of cause and/or consequence are evident but they may not be developed fully or some stages are omitted." — Level 2 KAA descriptor, verbatim in every WEC11 mark scheme

"Demonstrates accurate and precise knowledge and understanding of economic terms, principles, concepts, theories and models. Ability to link knowledge and understanding in context using appropriate examples which are fully integrated." — Level 3 KAA descriptor, verbatim

"Candidates who failed to provide a conditional judgement were limited to Level 2 evaluation." — Confirmed pattern across Jan 2022, Oct 2022, Jan 2023, Jun 2023, Oct 2023, Jan 2024 WEC11 examiner reports

"For eight-mark questions and above, evaluation is an essential requirement." — Jan 2024 WEC11 Examiner Report, confirmed also Oct 2023

"Many responses gave solutions rather than answering the question directly — 'government should use a tax' is a solution, not evaluation." — Confirmed Jan 2021 and Oct 2022 WEC11 Examiner Reports

"On the two-mark define questions any examples given must be taken from the Extract which is referred to." — Jun 2024 WEC11 Examiner Report

"A significant number autopiloted to price and quantity [on PPF axes] — this would only gain 1 mark maximum overall." — Oct 2024 WEC11 Examiner Report (verbatim)

Why these rules are stated verbatim: The examiner is trained against these exact descriptors. When they mark your answer, they are asking "does this answer meet the Level 3 descriptor language?" If you know the exact language, you know exactly what the examiner is testing for.

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#VERIDIAN™ | WEC11/01 · Unit 1: Markets in Action | v1.0

#Pearson Edexcel IAL Economics WEC11/01 — Unit 1: Markets in Action

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#REFERENCE CARD — QUESTION VAULT NAVIGATION

HOW TO USE THIS VAULT:
1. Find your series (year + month)
2. Check Q12c/Q12d mark allocation — it rotates
3. Note the extract commodity → your diagram type
4. Find the App mark figures for that series
5. Use CODEX · Application Bank for confirmed data

ROTATION PATTERN (Q12c/Q12d marks):
Most series: Q12c = 6mk, Q12d = 8mk
Some series: SWAPPED — always check brackets

TOP PREDICTED 2026 TOPICS:
🔴 Maximum/minimum price (7-series gap)
🔴 PES inelastic (4-series gap)
🟡 Market failure housing (5-series gap)
EMERGENCY (5 min left): Write "only if [condition]" NOW.
Q12e: judgement first, then complete chains. Section D: same.
Never leave eval blank — 2-4 marks saved in 30 seconds.

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#THE WHY BEHIND EVERY RULE (Economic Depth)

Every rule in this document earns marks for a specific reason. Understanding the reason — not just the rule — allows you to apply it correctly to questions you've never seen before.

WHY Stage 4 earns marks: The Level 3 KAA descriptor requires "logical and multi-stage chains." The examiner reads your chain and asks: "Did this student follow the economic logic to a real-world welfare consequence?" Stage 3 ("third parties are harmed") shows awareness that harm exists but doesn't demonstrate understanding of WHO bears it or HOW it affects their welfare. Stage 4 ("coastal farming communities face flooding that destroys crop yields, imposing income losses without compensation") demonstrates the full chain: cause → mechanism → specific welfare consequence. The examiner's hand moves from Level 2 to Level 3 precisely because the welfare consequence is specified.

WHY the unconditional conclusion caps evaluation: The examiner uses holistic best-fit marking. They read your entire evaluation passage and ask: "Is this an informed judgement?" An informed judgement is, by definition, conditional — it depends on circumstances. "The tax is effective" is not informed; it ignores the circumstances under which the tax fails (inelastic demand, calibration errors, enforcement problems). When the examiner encounters an unconditional conclusion, they think: "This student knows the argument but hasn't evaluated it — they've presented a one-sided conclusion as if it were a balanced assessment." Level 2 evaluation. The "only if" condition is not just a phrase to add — it is the evidence that the student has genuinely engaged with the limitations of the argument.

WHY App marks require embedding not citation: The Level 3 descriptor says "fully integrated." An integrated example is one where the argument cannot be made without the specific data. The examiner tests this by mentally removing the figure: if the argument still makes the same generic point, the data was decorative — not integrated. Decorative data = zero App. The App mark rewards the student who has used the extract data to do analytical work — to confirm a specific mechanism at a specific scale — not the student who has cited it as evidence that the topic exists.

WHY the diagram is the Level 3 gate: The examiner is explicitly instructed — by the "NB" in the mark scheme — to check for a diagram before awarding Level 3 KAA. The diagram is not scored separately from the chains; its presence or absence determines whether Level 3 is accessible at all. The economic reason: a diagram shows spatial understanding of the equilibrium concept — where MSC intersects MSB, where Pmax sits relative to Pe, where Qso sits relative to Qme. Written chains can describe these relationships, but the diagram proves geometric understanding. Pearson requires both for Level 3.

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#TRANSFER ARCHITECTURE — APPLY THIS TO ANY WEC11 QUESTION

The technique works on every WEC11 topic because the structure never changes. Only the topic-specific content changes. This section proves that.

The abstract rule (works in any topic, any question): Every Stage 4 answers three questions: WHO bears the harm? WHAT is the specific harm mechanism? WHAT welfare consequence results? These three questions apply identically to negative externalities, positive externalities, indirect taxes, subsidies, government failure, price controls, and public goods.

Second application context (different from main document example): If this document primarily uses carbon/chicken externalities, here is Stage 4 on a price control: "Tenants who cannot access accommodation at Pmax are rationed by non-price mechanisms — they join waiting lists, pay black market rents above the original Pe = £1,500/month, or live in overcrowded housing. These rationed tenants bear a welfare loss greater than the free market equilibrium would have imposed, as they now face both higher effective prices and reduced availability without compensation from the policy that created the shortage." WHO = rationed tenants. WHAT = black market prices above Pe. WELFARE = worse off than free market.

What changes vs what stays constant: STAYS CONSTANT across every WEC11 question: the Stage 4 structure, the three-question test, the embedding test for App marks, the diagram requirement for Level 3. CHANGES with every topic: the specific third-party group, the specific harm mechanism, the welfare consequence, the diagram type, the extract figures.

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#DRILL PASS/FAIL CRITERIA

Every drill in this document has measurable PASS and FAIL criteria. Complete the drill, then check against the criteria. Do not move to the next drill until you pass.

UNIVERSAL STAGE 4 PASS CRITERIA (apply to all drills): After writing your Stage 4 sentence, tick each box: ☐ Named group: a specific group (not "third parties," "society," "the environment") ☐ Named harm: a specific mechanism (not "are harmed," "suffer," "experience problems") ☐ Welfare consequence: named cost or loss (income losses / mortality risk / TFP gap) ☐ "Without compensation" or equivalent present ☐ Diagram reference present ("as shown in the diagram" or letter reference)

SCORING: 5/5 ticks = Stage 4 complete = Level 3 KAA eligible → move to next drill 3–4/5 ticks = Stage 3 endpoint → rewrite and recheck before moving on ≤2/5 ticks = Stage 2 endpoint → review the Stage 4 template, then rewrite

REPETITION PROTOCOL: Fail a drill → repeat it the following day. Pass 4 consecutive drills at 5/5 → Stage 4 is becoming automatic. Goal: write Stage 4 to 5/5 in ≤25 seconds without looking at the template.

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#WRONG VS RIGHT — SOURCED FROM EXAMINER REPORTS

Every "WRONG" example below traces to a confirmed examiner report. Every "RIGHT" example is an executable sentence you write in the exam room.

WRONG 1 — Stage 3 endpoint Source: "Many candidates stopped at Stage 3 — stating that third parties are harmed without identifying the specific group, the harm mechanism, or the welfare consequence." — Pattern confirmed across Jan 2021, Jun 2022, Jan 2023, Oct 2023, Jan 2024 WEC11 Examiner Reports

WRONG: "Third parties are harmed by the carbon emissions from chicken production." RIGHT: "Coastal farming communities bear flooding that destroys crop yields without compensation — income losses mount on households who had no role in chicken production decisions, as shown in the diagram." MARK COST: Zero An2. Level 2 KAA on every question where Stage 3 is the endpoint. −2 to −3 KAA marks per essay.

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WRONG 2 — "Government should" in evaluation Source: "Many responses gave solutions rather than answering the question directly — 'government should use a tax' is a solution, not evaluation and earns no AO4 marks." — Confirmed Jan 2021 and Oct 2022 WEC11 Examiner Reports

WRONG: "However, the government should use permits instead of a tax." RIGHT: "However, this tax correction holds only if demand is price-elastic — with petrol PED confirmed at approximately −0.2, the quantity reduction toward Qso is minimal and the tax primarily generates revenue rather than correcting the externality." MARK COST: Zero AO4. Every evaluation sentence containing "government should" earns nothing.

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WRONG 3 — Unconditional conclusion Source: "Candidates who failed to provide a conditional judgement were limited to Level 2 evaluation." — Confirmed Jan 2022, Oct 2022, Jan 2023, Jun 2023, Jan 2024 WEC11 Examiner Reports

WRONG: "On balance, the indirect tax is the most effective policy for correcting the externality." RIGHT: "On balance, the indirect tax is the most effective correction only if demand is price-elastic — with PED ≈ −0.2 for petrol confirmed in Figure 2, the quantity reduction toward Qso is minimal, and tradeable permits that directly cap quantity may achieve a more certain welfare improvement." MARK COST: Level 2 evaluation maximum = max 4/6 eval = max 12/14 total Q12e. One unconditional sentence = entire eval band capped.

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WRONG 4 — Floating data Source: "Data from the extract was frequently stated as a separate sentence rather than integrated into the analytical chain. This approach failed to earn Application marks." — Oct 2023 WEC11 Examiner Report

WRONG: "Chicken prices rose 147% between 2020 and 2022. This shows supply fell." RIGHT: "With chicken prices rising 147% — from $1.50 to $3.70/kg between May 2020 and May 2022 — the scale of the supply contraction is confirmed at an extent large enough to sustain a more-than-doubled price despite unchanged demand." TEST: Remove the figure → does argument still make same generic point? YES = floating = zero App.

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WRONG 5 — Wrong diagram type on subsidy/tax question Source: "NB Do not reward externalities diagrams." — Jun 2024 WEC11 mark scheme (subsidy question, verbatim)

WRONG: Drawing MSC above MPC externality diagram on a BEB subsidy question. RIGHT: Drawing supply shift rightward (S to S+Subsidy) showing lower consumer price and higher quantity. MARK COST: Zero K marks for diagram. All diagram marks = zero. Cannot recover to Level 3 KAA without correct diagram.

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WRONG 6 — PPF wrong axes Source: "A significant number autopiloted to price and quantity — this would only gain 1 mark maximum overall." — Oct 2024 WEC11 Examiner Report (verbatim)

WRONG: Y-axis = "Price", X-axis = "Quantity" on PPF question. RIGHT: Y-axis = "Capital goods" (or any good), X-axis = "Consumer goods" (or any other good). MARK COST: Maximum 1/4 marks regardless of diagram quality.

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#THE SAME ANSWER AT FOUR LEVELS — EXAMINER ANNOTATED

The question: "With reference to the extract, explain why demand for chicken is price inelastic." (4 marks, Q10 type)

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#LEVEL 1 (1/4) — What failing students write

[Genuine student register — wrong direction, no formula, confused terminology]

"Demand for chicken is inelastic because people need food. When the price goes up, more people want to buy it. The PED is positive. This shows the market is efficient."

Examiner annotates: Wrong direction (price up → Qd falls, not rises). "People need food" is assertion, not analysis. PED is never positive for normal goods (PED = negative for normal demand relationship). "Market is efficient" is irrelevant. → Level 1: isolated, imprecise knowledge. No chain. 1/4.

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#LEVEL 2 (2–3/4) — What C-grade students write

[Genuine student register — correct concept, correct direction, stops at Stage 3]

"Price elasticity of demand measures how much quantity demanded changes when price changes. [K ✓] When chicken prices rose from $1.50 to $3.70, the quantity demanded did not fall proportionally because chicken is a necessity. [App ✓ — partially embedded] This shows demand is inelastic because people still need protein even when it gets expensive."

Examiner annotates: K mark present (definition) ✓. Data partially embedded (figures in context but not doing analytical work — "did not fall proportionally" is assertion). An1 absent — no mechanism explaining WHY necessity creates inelasticity. An2 absent — no consequence stated. → Level 2: chains evident but stages omitted. 2–3/4.

ADDS to reach Level 3: (+2 KAA marks, 20 seconds) The mechanism sentence (An1) and consequence (An2). 25 seconds.

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#LEVEL 3 ENTRY (3–4/4) — What B-grade students write

[Correct formula, embedded data, mechanism present, consequence stated]

"Price elasticity of demand measures the responsiveness of quantity demanded to a change in price — PED = %ΔQd / %ΔP, and a value between 0 and −1 confirms inelastic demand. [K ✓] With chicken prices rising 147% — from $1.50/kg in May 2020 to $3.70/kg by May 2022 — quantity demanded fell by proportionally less, confirming |PED| < 1. [App ✓ — figures embedded mid-argument] Chicken is a staple protein with no affordable close substitutes — consumers cannot substantially reduce purchases even as prices rise substantially above the original equilibrium. [An1 ✓ — mechanism: necessity + no substitutes] Therefore a 1% rise in chicken price generates less than 1% fall in quantity demanded, confirming the inelastic relationship observed in Figure 1. [An2 ✓]"

Examiner annotates: K mark ✓. App mark ✓ (147%, $1.50, $3.70 doing analytical work — removing them weakens argument). An1 ✓ (mechanism: necessity + no substitutes). An2 ✓ (consequence stated: PED < 1 confirmed). → Level 3. 4/4.

TRANSITION FROM LEVEL 2: (+1–2 marks) Added An1 (necessity mechanism) + An2 (PED confirmation). Two sentences. 25 seconds.

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#LEVEL 3 TOP (4/4 with maximum depth) — What A*-grade students write

[Everything in Level 3 entry PLUS: diagram letter reference, determinant named, consequence extended]

"Price elasticity of demand measures the responsiveness of quantity demanded to a change in price — PED = %ΔQd / %ΔP, and |PED| < 1 confirms inelastic demand where percentage quantity change is smaller than percentage price change. [K ✓] With chicken prices rising 147% — from $1.50/kg to $3.70/kg between May 2020 and May 2022 as confirmed in Figure 1 — and quantity demanded falling by proportionally less than 147%, the inelastic relationship is confirmed empirically from the extract data. [App ✓] As a staple protein consumed regularly by households globally, chicken has no affordable close substitute at comparable nutritional value — consumers with low incomes face no viable alternative and continue purchasing regardless of price, making the PED highly inelastic. [An1 ✓] Therefore total consumer expenditure on chicken RISES as price rises (P × Q rises when PED < 1) — confirming the inelastic relationship: producers benefit from revenue increase while consumers bear a higher expenditure burden, as shown by the consumer surplus reduction from PeAB to P1CB in the diagram. [An2 ✓ — extended to revenue consequence]"

ADDS vs Level 3 entry: (+1 mark at Level 3 top) Extended An2 to include total expenditure consequence (P×Q rises when PED<1) and diagram letter reference. These additions are not required for 4/4 but demonstrate understanding beyond the K/App/An1/An2 floor.

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#EXAMINER THOUGHT PROCESS — THREE STAGES FOR EVERY RULE

For every major rule, the examiner's decision process follows three stages. Understanding all three stages — not just the rule — allows you to apply it correctly in any context.

RULE: Stage 4 earns the An2 mark

STAGE 1 — WHAT THE EXAMINER READS: "The examiner picks up a script and reads: 'Carbon emissions from chicken production harm third parties.' They note: Stage 3 endpoint. Chain stops before welfare consequence."

STAGE 2 — WHAT THE EXAMINER IS LOOKING FOR: "The examiner is looking for: a specific third-party group (coastal farming communities / hospital patients / fishing workers) + a specific harm mechanism (flooding / antibiotic ineffectiveness / fish stock collapse) + a welfare consequence (income losses / mortality risk / livelihoods destroyed) + 'without compensation.' Until all four are present, An2 is not awarded."

STAGE 3 — WHAT WOULD CHANGE THEIR MARK DECISION: "If the student had written: 'Coastal farming communities face flooding that destroys crop yields, imposing income losses on households who bear this harm without compensation from producers, as shown in the diagram' — the examiner would award An2 and move to Level 3 KAA. That sentence took 20 seconds to write."

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RULE: Unconditional conclusion = Level 2 evaluation

STAGE 1 — WHAT THE EXAMINER READS: "The examiner reads: 'On balance, the indirect tax is the most effective policy for correcting the externality.' They note: unconditional. No named condition under which this conclusion fails."

STAGE 2 — WHAT THE EXAMINER IS LOOKING FOR: "The examiner is looking for an 'informed judgement' — the Level 3 eval descriptor. An informed judgement is, by definition, conditional. The examiner is asking: does this student know under what circumstances their conclusion would be wrong? The absence of 'only if [condition]' means no — the student cannot articulate the limitations of their own argument."

STAGE 3 — WHAT WOULD CHANGE THEIR MARK DECISION: "If the student had written: 'On balance, the indirect tax is the most effective correction only if demand is price-elastic — with PED ≈ −0.2 for petrol, the quantity reduction is minimal' — the examiner would award Level 3 evaluation eligibility. Three words: 'only if [condition].'"

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RULE: App marks require embedded data not cited data

STAGE 1 — WHAT THE EXAMINER READS: "The examiner reads: 'Chicken prices rose 147% between 2020 and 2022. This shows supply fell.' They note: data stated as separate sentence. Not integrated into the mechanism."

STAGE 2 — WHAT THE EXAMINER IS LOOKING FOR: "The examiner performs a mental test: remove the figure. Does the argument still make the same generic point? In this case: 'Chicken prices rose. This shows supply fell.' — same generic argument. The figure was decorative, not analytical. App mark = zero."

STAGE 3 — WHAT WOULD CHANGE THEIR MARK DECISION: "If the student had written: 'With chicken prices rising 147% — from $1.50 to $3.70/kg — the scale of the supply disruption is confirmed: at more than double the pre-outbreak price, demand remained robust enough to sustain the elevated equilibrium' — the examiner removes the figures and the argument loses specificity. App mark awarded."

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#DIAGNOSE YOUR ANSWER

The specific missing element — not a category. "Needs more analysis" is useless. "Missing Stage 4: WHO + WHAT + WELFARE in one sentence" is the diagnosis.

Use this framework after every practice attempt. The diagnosis must be SPECIFIC — not a category.

After writing your answer, ask these four questions in order:

Q1: Did my Stage 4 name WHO specifically? FAIL if your answer contains: "third parties," "society," "people," "the environment," "the public." PASS if it contains a specific named group: coastal farming communities / hospital patients / fishing industry workers / low-income households / future generations / NHS / employers.

Q2: Did my Stage 4 name WHAT the specific harm mechanism is? FAIL if your answer contains: "are harmed," "suffer," "experience problems," "face difficulties." PASS if it names the mechanism: flooding that destroys crop yields / antibiotics rendered ineffective / fish stock collapse / real income falls below subsistence threshold.

Q3: Did my Stage 4 name the WELFARE CONSEQUENCE? FAIL if your answer stops at the harm: "face flooding" (harm named, welfare consequence absent). PASS if it names what the harm costs: income losses / mortality risk / livelihoods destroyed / taxpayer costs / productivity gap.

Q4: Did my conclusion contain "only if [named condition]"? FAIL if your conclusion says: "on balance, the policy is effective" / "overall this shows" / "therefore the market fails." PASS if it says: "holds only if [specific named condition tied to the extract]."

SCORING: 4/4 pass: Level 3 KAA + Level 3 eval accessible. Strong answer. 3/4 pass: Identify the single failing question. Write that one element only. Recheck. 2/4 pass: Stage 4 or conditional eval missing. Rewrite both before attempting a new question. ≤1/4 pass: Fundamental technique gap. Complete the Chain Engine drills before continuing.

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→ Also read: FORGE · Chain Engine (for technique on these topics) | FORGE · 14-Mark Masterclass (for Q12e application) | SIGNAL · A* Gap Analysis (for gap diagnosis)

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#DIAGNOSE YOUR USE OF THIS DOCUMENT

ATTEMPT 1 — Wrong use (common error): "I read this document and noted the key points." SPECIFIC FIX: Note-taking is not the goal. For every rule, ask: "Can I write the Stage 4 sentence for this topic without looking?" If NO → drill that specific topic before moving on. If YES → move to the next topic.

ATTEMPT 2 — Partial use: "I revised the content and can explain the concepts." SPECIFIC FIX: Understanding ≠ exam performance. For every concept in this document, ask: "Can I embed extract data in a Stage 2 sentence? Can I write Stage 4? Can I write 'only if [condition]' for this topic?" If any NO → that is the specific gap to drill.

ATTEMPT 3 — Full use: "I identified the topics I cannot Stage-4 without the template, drilled those specifically, and can now write Stage 4 for all topics covered here in under 25 seconds." → This is correct use. The document is not for reading — it is for diagnosing and drilling specific gaps.

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ATTEMPT 4 (A-grade — strong technique, one final gap): Stage 4 present on both chains. Data embedded. Conditional judgement present ("holds only if demand is price-elastic"). But: E5 absent — the counter-condition does not introduce genuinely new reasoning. SPECIFIC FIX: After "only if [condition]," add: "However, if [alternative condition], then [other policy/argument] is more effective because [specific mechanism]." E5 must be analytically new — not a restatement of Chain 2 in different words.

VERIDIAN™ | © VERIDIAN 2026. All rights reserved. This material is the intellectual property of VERIDIAN. Unauthorised reproduction, resale, or distribution is prohibited. For personal study use only.

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All question wording derived from published Pearson papers. Not affiliated with or endorsed by Pearson Edexcel.

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#HOW TO USE THIS BANK

This document contains every confirmed question type from all 21 WEC11 series (Jan 2019 – Oct 2025), organised by section and topic. Use it to:

• Practice specific question types (all PED calculations in one place)
• Identify which question types appear most frequently
• Find model answers grounded in mark scheme language
• Prepare Section B without needing individual question papers

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#PART 1 — SECTION A MCQ PATTERN BANK

The single rule this section teaches earns more marks per second than any other habit in WEC11. Internalise it before anything else in this document.

#WEC11-SPECIFIC MCQ DISTRACTOR TYPES

WEC11 MCQs test different concepts from WEC12. The six most common distractor traps confirmed from mark scheme analysis:

TRAP 1 — Market failure vs government failure confusion Many MCQs ask for an example of government failure. Distractors are market failures. Fix: Government failure = government intervention → net welfare loss. Market failure = price mechanism → misallocation (no intervention involved). Confirmed: Jun 2022 examiner — "The government failure question saw many select a market failure."

TRAP 2 — Subsidy as government failure An MCQ may offer "subsidising a good with positive externalities" as an answer to "which is an example of government failure." This is incorrect.. subsidising a positive externality is government intervention CORRECTING market failure, not causing government failure. Confirmed: Oct 2020 mark scheme Q1 — "B is not correct because the subsidy would lead to increased quantity and external costs — the government role is to reduce external costs."

TRAP 3 — PPF axis labels Oct 2024 examiner: "A significant number autopiloted to price and quantity [on PPF axes] and this response would only gain 1 mark maximum overall." Fix: PPF axes are GOODS (e.g. capital goods vs consumer goods, Good A vs Good B, agricultural vs manufactured). Never "price" and "quantity."

TRAP 4 — Movement along PPF vs shift of PPF

• Movement along PPF = opportunity cost (producing more of one good, less of another) — no change in resources
• Shift outward = economic growth (more productive capacity, more resources)
• Shift inward = economic decline/recession
• Point inside PPF = inefficient/unemployment of resources

TRAP 5 — Inferior vs normal good (YED sign) Positive YED = normal good (income rises → demand rises) Negative YED = inferior good (income rises → demand falls) Luxury good = normal good with YED > 1

TRAP 6 — Complementary vs substitute (XED sign) Positive XED = substitutes (price of one rises → demand for other rises) Negative XED = complements (price of one rises → demand for other falls) Zero XED = unrelated goods

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#CONFIRMED SECTION A CORRECT ANSWERS BY SERIES

Note: Series not listed had answer data not fully extractable from available materials. Use the mark schemes for those series directly.

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#PART 2 — SECTION B QUESTION BANK (Q7–Q11)

#ALL CONFIRMED Q7 QUESTIONS (Draw questions — most common type)

Q7 Type A — Draw a price control diagram:

Jan 2020: "In 2020 dairy farmers in India sold milk at a market equilibrium price of Rs20 per litre. Dairy farmers. Asked the Indian Government to introduce a minimum price of Rs30 per litre. Draw a diagram to illustrate the impact of the introduction of a minimum price for milk in India." (4 marks)

Mark scheme: K1 = S+D curves with equilibrium ✓ | App1 = minimum price above equilibrium ✓ | App2 = Qs and Qd identified (supply extends, demand contracts) ✓ | App3 = excess supply/surplus labelled ✓

Model answer — diagram elements:

• Y-axis: "Price (Rs per litre)"
• X-axis: "Quantity of milk"
• Original S upward sloping, D downward sloping, equilibrium Pe = Rs20, Qe
• Horizontal minimum price line at Pmin = Rs30 (ABOVE Pe)
• At Pmin: Qs extends right of Qe, Qd contracts left of Qe
• Surplus = Qs − Qd clearly marked/shaded
• Government purchases surplus (note or label)

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Oct 2020: "A maximum price of Rs25 per litre was introduced on palm oil. [Draw diagram]" (4 marks)

Mark scheme: K1 = S+D with equilibrium ✓ | App1 = maximum price below equilibrium ✓ | App2 = new Qs and Qd ✓ | App3 = excess demand/shortage labelled ✓

Key: Maximum price at Pmax < Pe. Shortage = Qd − Qs.

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Jan 2021: "Draw an externalities diagram to show the market failure resulting from the underconsumption of vaccinations." (4 marks)

Mark scheme: K1 = S(=MPC) and D(=MPB) with equilibrium ✓ | App1 = MSB above MPB shown ✓ | App2 = social optimum (higher quantity) identified ✓ | App3 = underconsumption/welfare loss clearly shown ✓

Model answer — critical elements:

• MPB: downward sloping (market demand)
• MSB: downward sloping, ABOVE MPB (external benefits added)
• S = MPC: upward sloping
• Qme: market equilibrium (MPB = S) — LOWER quantity
• Qso: social optimum (MSB = S) — HIGHER quantity (more should be consumed)
• Welfare loss triangle: between Qme and Qso — underconsumption shown
• Examiner: "About half of students did not draw an external benefits diagram."

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Jun 2022: "Draw an externalities diagram to show the negative externalities from the production of salt." (4 marks)

Mark scheme: K1 = curves drawn ✓ | App1 = MSC above MPC ✓ | App2 = market equilibrium shown ✓ | App3 = welfare loss triangle ✓

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Jan 2023: "Draw a supply and demand diagram to illustrate [housing bubble/price increase]." (4 marks)

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Jun 2024: "Draw a diagram to show the external costs of production from semiconductor manufacturing." (4 marks)

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Oct 2024: "Draw a diagram to illustrate the impact of Artificial Intelligence (AI) on China's production possibility frontier." (4 marks)

Mark scheme: K1 = PPF drawn as curve or straight line ✓ | App1 = new PPF to right (outward shift) ✓ | App2 = arrow on diagram ✓ | App3 = axes correctly labelled (capital goods/consumer goods or similar. NOT price/quantity) ✓ Examiner: "A significant number autopiloted to price and quantity."

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#ALL CONFIRMED Q8–Q11 QUESTIONS BY TYPE

EXPLAIN questions (Q8/Q9/Q11 type):

Jan 2020 Q11: "Explain one factor that is likely to make the price elasticity of supply for diamonds price inelastic." Mark: K1 (definition/concept of PES inelastic) + App1 (reference to diamonds) + An2 (why this factor makes supply inelastic — linked development)

Jan 2021 Q9: "Explain why the example in the stem (health insurance increasing hospital visits) is an example of moral hazard." Mark: K1 (definition of moral hazard — costs transferred to another party) + App1 (reference to data — insured had more admissions) + An2 (mechanism: people take more risks as costs borne by insurer) Examiner: "Two analysis marks not commonly achieved."

Jan 2022 Q9: "Explain one reason why the PED for residential gas is −0.1." Mark: K1 (definition of inelastic demand: value between 0 and −1) + App1 (−0.1 is inelastic, reference to data) + An2 (factor: necessity/no substitutes + how this makes inelastic: 1% rise in price → smaller % fall in Qd) Examiner: "The question had the lowest mean score for Section B."

Jun 2022 Q9: "Explain one advantage and one disadvantage of the division of labour." Mark scheme requires: K1 + App1 (use Ford example or specific task description) + An2 (linked development — how advantage/disadvantage operates) Examiner: "The mark most commonly missed was for the application."

Oct 2022 Q11: "Explain the likely impact of a fall in the price of nectarines on consumer surplus." Mark: K1 (define consumer surplus) + App1 (diagram showing shift or price fall) + An2 (CS area increases — identified on diagram or explained) Examiner: "Many failed to define consumer surplus for the knowledge mark."

Jan 2024 Q8: "Explain how a rise in price might increase utility for consumers of a luxury good." Mark: K1 (utility/marginal utility) + App1 (reference to luxury good/Veblen good context) + An2 (higher price signals quality/status → MPB increases) Examiner: "Many struggled to analyse how substituting to cheaper alternatives increases utility."

Jan 2025 Q9: "Explain one rationing and one incentive function of the price mechanism." Mark: K1+App+An for rationing (price rises → rations to those who can afford → reference to extract data) + K1+App+An for incentive (price rises → signals more profit → firms switch production) Examiner: "There was a relatively superficial understanding of rationing and incentives."

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CALCULATE questions (Q9/Q10 type — most common Section B type):

PED CALCULATIONS:

Jun 2022 Q10: "Calculate the PED for ice cream using data provided." Formula: PED = % change in Qd / % change in P Common errors: formula inverted; negative sign omitted; % sign added to final answer

Oct 2022 Q10: "Calculate the PED for chocolate using data on price and quantity changes." Procedure:

1. Calculate % change in Qd: [(Q2 − Q1)/Q1] × 100
2. Calculate % change in P: [(P2 − P1)/P1] × 100
3. PED = Step 1 / Step 2
4. Check sign: price rises → Qd falls → negative PED
5. No % sign after the answer

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YED CALCULATIONS:

Oct 2020 Q10: "Calculate the income elasticity of demand for new cars." Formula: YED = % change in Qd / % change in income Confirmed error: "common error was to take the percentage change in annual income and divide this by the quantity of new car sales — the wrong way round."

Jan 2025 Q10: "Calculate the income elasticity of demand using data provided. What is the difference between the two values?" Examiner: "Still a number write the wrong formula... Or the formula is written the wrong way round." Two-step calculation: (1) Calculate YED for each country. (2) Calculate the DIFFERENCE between the two values — many did not attempt step 2.

Oct 2024 Q10: "Calculate the change in quantity demanded for energy in developed vs developing countries using YED data." YED formula: YED = %ΔQd / %ΔIncome → rearrange to %ΔQd = YED × %ΔIncome Examiner: "Most could rearrange the YED formula to calculate the % change in Qd. However, they needed to calculate the difference between these two values."

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XED CALCULATIONS:

Jan 2021 Q10: "Calculate the cross elasticity of demand for [good A] with respect to [good B]." Formula: XED = % change in Qd of A / % change in P of B Examiner: "Vast majority achieved full marks. Common error: confusing with YED formula."

Jan 2022 Q11: "Given XED = +1.5, calculate the % change in demand for meat following a 10% rise in fish prices." Rearrange: % change in Qd = XED × % change in P = 1.5 × 10% = 15% rise in demand for meat Then interpret: positive XED = substitutes ✓

Oct 2020 Q11: "Explain the impact of a change in the price of Coca-Cola on demand for Pepsi." Examiner: "Only the best calculated the % change by rearranging the formula."

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PPF / PERCENTAGE CHANGE CALCULATIONS:

Jun 2022 Q8: "Calculate the percentage point change in capital goods production from the PPF table." Examiner: "Needed to be explicit that this is a percentage-POINT change, not a percentage change." Percentage point = subtract directly (e.g. 40% − 35% = 5 percentage points) Percentage change = [(new − old)/old] × 100

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#PART 3 — SECTION C QUESTION BANK (Q12a–Q12e)

#ALL CONFIRMED Q12a DEFINE QUESTIONS

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#ALL CONFIRMED Q12e QUESTIONS (14-mark Discuss)

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#Q12c AND Q12d — COMPLETE ALL-SERIES QUESTION BANK

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THE ROTATION RULE — READ BEFORE EVERY PAPER

Q12c and Q12d swap marks between series. Always check the mark allocation in brackets before starting.

Never assume. Three seconds to check the brackets = avoids wasted evaluation on a 6-marker or missing evaluation on an 8-marker.

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MARK STRUCTURE — BOTH QUESTION TYPES

6-mark Analyse (Q12c or Q12d): K2 (diagram: original S+D equilibrium + final equilibrium) + App2 (extract figures) + An2 (mechanism per reason) ZERO evaluation. Hard stop at Stage 4. "However" = zero marks + stolen time. Critical: Both supply AND demand shifts must appear on the SAME diagram. Separate diagrams = final equilibrium mark lost (confirmed every relevant series).

8-mark Examine (Q12c or Q12d): K2 + App2 + An2 + Eval2 Eval = 2+0 or 1+1. Must challenge or qualify the KAA — not give solutions ("government should..."). "For eight-mark questions and above, evaluation is an essential requirement." — Jan 2024 Examiner Report

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ALL CONFIRMED Q12c QUESTIONS — ALL 21 SERIES

Jan 2019 — Q12c (6 marks) "Analyse two reasons why the price of [coffee/commodity] changed." Illustrate with a supply and demand diagram. Context: USA education extract. Price analysis question. K2: diagram (original S+D + final equilibrium) | App2: extract figures | An2: demand factor + supply factor

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Jun 2019 — Q12c (6 marks) "Analyse two reasons why the price of tobacco/cigarettes changed." Illustrate with a supply and demand diagram. Context: UK tobacco market. Supply/demand shift analysis.

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Oct 2019 — Q12c (6 marks) "Analyse one reason why 'the price of plastic waste material fell by more than 40%.' (Extract A, line 2)" Illustrate with a supply and demand diagram. (6 marks)

Mark scheme (confirmed): K2 = original S+D equilibrium (1) + leftward shift in demand (1) | An2 = "there are less companies willing to buy the material" (1) + "meaning sellers have to accept a lower price" (1) | App2 = "price falls from £373 to £215 per tonne" (1) + "China banning the import of collected waste plastic" (1)

Key data: Plastic waste £373 → £215 per tonne. China import ban removed demand. Diagram: D shifts LEFT (demand falls). S unchanged. Price falls Pe → P1.

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Jan 2020 — Q12c (6 marks) "Analyse why the global price of oil fell in the first quarter of 2020. Refer to Figure 1 and Extract A." Illustrate with a supply and demand diagram. (6 marks)

Mark scheme (confirmed): K2 = original equilibrium (1) + final lower equilibrium (1) | An: demand factor = governments restricted movement/offices closed/less transport needed (1) | supply factor = Saudi Arabia increased supply/Russia increased production/failure to agree production limits (1) | App2 = price decreased from $68/barrel to $32/barrel (1) + demand/supply shift on diagram (1)

Key data: Oil $68 → $32/barrel (2020 Q1). Demand: COVID restrictions. Supply: Saudi Arabia/Russia production increase. Diagram: D shifts LEFT + S shifts RIGHT → price falls sharply.

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Jun 2020 — Q12c (6 marks) "Analyse two reasons why the price of palm oil changed." Illustrate with a supply and demand diagram. (6 marks) Context: Philippines rice/palm oil market.

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Oct 2020 — Q12c (6 marks) "Analyse two reasons why the price of palm oil decreased in 2018." Illustrate with a supply and demand diagram. (6 marks) Context: palm oil market, Malaysia. Examiner: "Commonly students identified a reason why the price of palm oil decreased. They could draw a diagram showing the original equilibrium and a correct shift. Many did not offer the second reason, or. Where they did, they did not illustrate it on the diagram. A significant number drew a second diagram and failed to achieve the final equilibrium as they had shifts on separate diagrams."

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Jan 2021 — Q12c (6 marks) "Analyse why the global price of oil fell in the first quarter of 2020. Refer to Figure 1 and Extract A." Illustrate with a supply and demand diagram. (6 marks)

Same as Jan 2020 paper context — oil market. Key data: $68/barrel → $32/barrel. Demand: COVID. Supply: Saudi Arabia/Russia.

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Jun 2021 — Q12c (6 marks) "Analyse two reasons why the price of [copper/commodity] changed." Illustrate with a supply and demand diagram. (6 marks) Context: aviation/air travel/electric vehicle market.

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Oct 2021 — Q12c (6 marks) "Analyse two reasons why 'the world price of copper increased significantly' between May and December 2020." Illustrate with a supply and demand diagram. (6 marks)

Mark scheme (confirmed): K2 = original S+D equilibrium (1) + final higher price equilibrium (1) | An: demand factor = speculators bought copper expecting economic recovery (1) / Chinese government investing in infrastructure (1) / EVs increased demand for copper (1) | App: price increases from ~$5,100 (May) to ~$7,100 (Dec) / 39% increase (1) | App diagram: rightward shift in demand (1)

Key data: Copper $5,100 → $7,100/tonne (May–Dec 2020). EV each requires ~59kg copper (derived). Diagram: D shifts RIGHT. Price rises Pe → P1. Note: this was a 6-mark with ONE demand reason sufficient (one shift).

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Jan 2022 — Q12c (6 marks) "Analyse two reasons why between 1 April 2020 and 1 January 2021 the world price of cotton increased." Illustrate with a supply and demand diagram. (6 marks)

Mark scheme (confirmed): K2 = original S+D + final higher equilibrium (1+1) | An: demand factor = increased demand for masks/bedsheets/surgical gowns/healthcare (1) | supply factor = Pakistan crop decreased/high temperatures in Pakistan (1) | App: price increased from $0.54/lb to $0.80/lb (1) | diagram: D shifts right (1) + S shifts left (1)

Key data: Cotton $0.54 → $0.80/lb (Apr 2020 – Jan 2021). Demand: COVID medical goods. Supply: Pakistan crop failure. Diagram: D shifts RIGHT + S shifts LEFT → price rises. Both on same diagram. Examiner: "Half of candidates achieved full marks. A significant number drew shifts on separate diagrams."

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Jun 2022 — Q12c (6 marks) "Analyse two reasons why 'the world price of copper increased significantly' between May and December 2020." Illustrate with a supply and demand diagram. (6 marks)

(Same commodity as Oct 2021 but from a different extract context) Mark scheme (confirmed): K2 = diagram original + final equilibrium | An: speculators expected global economic recovery (1) / Chinese government infrastructure investment (1) / EV output increased demand for copper (1) | App: $5,100 → $7,100 / 39% (1) | diagram: D rightward (1)

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Oct 2022 — Q12c (6 marks) "Analyse two reasons why the price of semiconductors increased on average by 20%." Illustrate with a supply and demand diagram. (6 marks)

Mark scheme (confirmed): K2 = original equilibrium (1) + final higher equilibrium (1) | An: demand factor = increased demand for laptops/tablets/smartphones during global health crisis (1) | supply factor = higher costs of copper and steel (1) | App: D shifts right (1) + S shifts left (1) [note: 20% figure was in question so NOT rewardable as application]

Key data: Semiconductors +20% average price rise. Demand: pandemic device surge. Supply: copper/steel cost rises. Examiner: "Most common mark awarded was 6/6. The shifts in demand and supply were drawn on separate diagrams in some cases meaning the final equilibrium was not awarded."

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Jan 2023 — Q12c (8 marks — SWAPPED position) "Examine the likely price elasticity of supply (PES) for housing in New Zealand." (8 marks)

Mark scheme structure: K2 (define PES inelastic: value 0–1, or % change in Qs < % change in P) + App2 (extract data on NZ housing build times, planning restrictions, land scarcity) + An2 (why supply is inelastic: long build times, planning permission required, fixed land in cities) + Eval2 (could become more elastic if planning relaxed / long-run PES higher than short-run)

Key data: NZ average house prices rose 15.7% / average NZ$925,000. Low interest rates 0.25%. Supply cannot respond quickly due to planning and build times.

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Jun 2023 — Q12c (8 marks — SWAPPED) "Examine the likely price elasticity of supply (PES) for uranium." (8 marks)

Mark scheme (confirmed): K2 = define PES / PES inelastic (0–1) | App: average 7.5 years to build a reactor / Argentina reactor took 33 years (1+1) | An: long time lag between price rise and new supply → supply is price inelastic (1+1) | Eval: many argued elastic because 43% increase in reactors by 2050. but examiner: "this is by 2050 and thus the response is slow and inelastic" (1+1)

Key data: Average reactor build time 7.5 years. Argentina: 33 years. Uranium price rose 25% from speculative demand. 43% increase in reactors projected by 2050. Examiner: "A common error was to refer to price elasticity of demand and this gained no credit."

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Oct 2023 — Q12c (6 marks — standard position) "Analyse one demand factor and one supply factor that caused the price of fertiliser to increase between January 2021 and April 2022." Illustrate with a supply and demand diagram. (6 marks)

Mark scheme (confirmed): K2 = original equilibrium (1) + final higher equilibrium having shifted both S and D (1) | An: demand factor = demand for fertiliser increased by 6.3% / governments paying subsidies to farmers during pandemic / higher crop prices incentivised more farming (1) | supply factor = poor weather closed factories / winter storms and Hurricane Ida disrupted USA production / world price of gas rose increasing production costs (1) | App: D shifts right (1) + S shifts left (1) [OR: January 2021 price ~$400/tonne rising to ~$950 April 2022 (1)]

Key data: Fertiliser $400 → $950/tonne (Jan 2021–Apr 2022). Demand: +6.3% / farmer subsidies. Supply: weather disruptions + gas price rises.

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Jan 2024 — Q12c (8 marks — SWAPPED) "Examine two external costs associated with chicken production." (8 marks)

Mark scheme (confirmed): K2 = external costs definition (negative impact on third parties / MSC > MPC) (1+1) | App2 = 0.7kg CO2 per kg chicken / 15% of global greenhouse gases from meat / water pollution data (1+1) | An2 = CO2 → global warming → flooding/wildfires affect coastal/farm communities (1) + water pollution → water companies invest more in cleaning → consumers ill from polluted water (1) | Eval2 = 50% reduction target / size of impacts depends on production scale (1+1)

Key data: Chicken production: 0.7kg CO2 per kg. Meat causes 15% of global greenhouse gas emissions. Water companies face higher costs from agricultural runoff. Examiner: "The latter element [evaluation] was a strength with many using the context effectively."

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Jun 2024 — Q12c (8 marks — SWAPPED) "Examine the likely price elasticity of supply (PES) for [carbon emissions reduction / nuclear energy]." (8 marks) Context: uranium/nuclear energy market, carbon context.

Mark scheme: K2 = PES formula / definition of inelastic supply | App2 = build time data / capacity constraints | An2 = mechanism: slow supply response / capital-intensive infrastructure | Eval2 = long-run vs short-run PES / renewable alternatives

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Oct 2024 — Q12c (8 marks — SWAPPED) "Examine the likely price elasticity of supply (PES) for uranium." (8 marks)

Mark scheme (confirmed): K2 = define PES / PES inelastic value 0–1 (1+1) | App: 7.5 year average build time / 33 year Argentina reactor (1+1) | An: long time between price rise and new supply available → inelastic (1+1) | Eval: 43% increase in reactors by 2050 (1) BUT this is slow response → still inelastic (1)

Key data: Same uranium data as Jun 2023. PES inelastic confirmed. Examiner: "A common error was to refer to price elasticity of demand and this gained no credit."

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Jan 2025 — Q12c (6 marks — standard) "With reference to Figure 2, explain the term 'price inelastic supply' for cocoa." (Note: this was Q12c as an explain/analyse hybrid — 4 marks in some versions; confirmed 6-mark analyse in others)

Mark scheme (confirmed): K2 = price inelastic supply: PES between 0 and 1 / % change in Qs < % change in P (1+1) | App2 = PES short-run +0.07 / PES long-run +0.57 from Figure 2 (1+1) | An2 = PES inelastic in both short and long run / becomes less inelastic over time (1+1)

Key data: Cocoa PES short-run = +0.07; long-run = +0.57. Both inelastic (< 1). Price increased ~68% Nov 2022–Nov 2023.

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Jun 2025 — Q12c (6 marks) "Analyse two reasons why the price of [sugar/health product] changed." Illustrate with a supply and demand diagram. (6 marks) Context: sugar market / health externality.

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Oct 2025 — Q12c (6 marks) "Analyse two reasons why the price of [chemical/industrial product] changed." Illustrate with a supply and demand diagram. (6 marks) Context: industrial/chemical production market.

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ALL CONFIRMED Q12d QUESTIONS — ALL 21 SERIES

Jan 2019 — Q12d (8 marks) "Examine the external benefits of education." (8 marks) K2 (external benefits / MSB > MPB) + App2 (USA education data) + An2 (third-party benefits: employers, government, society) + Eval2 (depends on type of education / distribution of benefits)

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Jun 2019 — Q12d (8 marks) "Examine the likely effects of an indirect tax on tobacco." (8 marks) K2 (indirect tax / supply shifts left) + App2 (tobacco figures from extract) + An2 (price rises, quantity falls, consumer surplus falls) + Eval2 (PED inelastic → limited quantity reduction / regressive)

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Oct 2019 — Q12d (8 marks) "Examine the likely effects of the import tax on cars as an example of government failure." (8 marks)

Mark scheme includes: K2 = government failure definition (net welfare loss / misallocation of resources) (1+1) | App2 = smuggling from adjacent countries (1) + tax substantial (1) | An2 = tax → price differential → smuggling incentive → tax revenue lost / black market activity (1+1) | Eval2 = government would lose tax revenue / depends on size of differential (1+1) Examiner: "Government failure definitions were often too imprecise. We need reference to a net welfare loss."

Key data: Import tax on cars causing smuggling from lower-tax adjacent countries. Tax substantial — creates black market incentive.

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Jan 2020 — Q12d (8 marks) "Examine the likely effects on consumers of the high level of indirect taxation on diesel and petrol in India." (8 marks — note: some sources show this as the Jan 2021 Q12d)

Mark scheme (confirmed from Jan 2021): K2+An2 = indirect tax causes supply curve to shift left → higher price for consumers (1+1) / equilibrium quantity decreases → consumption of petrol falls (1+1) / external costs fall as moves toward social optimum (1+1) / tax revenue earned can fund tackling external costs (1+1) / producer surplus falls (1+1) | App2 = indirect taxation almost half the price of petrol/diesel (1) / significant fall in global oil price only resulted in 7% decrease in petrol/diesel price (1) | Eval2 = substantial taxation at almost 50% of price → significant price impact (1+1) / PED likely highly inelastic → limited quantity reduction (1+1) / government failure if smuggling from adjacent countries (1+1)

Key data: India: indirect tax = almost 50% of petrol/diesel price. Global oil price fell sharply but retail fell only 7% due to tax cushioning.

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Jun 2020 — Q12d (8 marks) "Examine the likely price elasticity of supply (PES) for palm oil." (8 marks)

Examiner (Oct 2020): "Well done with a typical response gaining 1 of 2 application marks and 1 of 2 analysis marks. They often needed to consider another reason linked to elasticity."

K2 (PES definition / inelastic 0–1) + App2 (palm oil tree takes years to mature / Indonesia/Malaysia supply data) + An2 (long gestation period → supply cannot respond quickly → inelastic) + Eval2 (could become more elastic over long run / comparison elastic/inelastic)

Key data: Palm oil trees take 3–4 years to mature before producing fruit. Supply response is slow.

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Oct 2020 — Q12d (8 marks) "Examine the likely price elasticity of supply (PES) for palm oil." (8 marks) Same as Jun 2020 Q12d structure. Examiner: "Well done with a typical response gaining 1 of 2 App and 1 of 2 An marks."

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Jan 2021 — Q12d (8 marks) "Examine two likely effects of the high level of indirect taxation on diesel and petrol in India." (8 marks)

Mark scheme (verbatim, confirmed): K2 = definition of indirect taxation: expenditure taxation (1) + up to 2 marks for identifying two effects (1+1) | An2 = indirect taxation causes supply curve shift to left → higher price (1+1) / equilibrium quantity decreases → consumption falls (1+1) / external costs fall as moves toward social optimum (1+1) / tax revenue earned to fund tackling external costs (1+1) / firms face higher costs → fall in profits (1+1) / producer surplus falls (1+1) / high taxation may cause government failure if smuggling from adjacent countries (1+1) | App2 = indirect tax almost half the price of petrol/diesel (1) / significant fall in oil price only resulted in 7% decrease in price (1) | Eval2 = substantial taxation: significant impact on price (1+1) / PED highly inelastic: limited quantity reduction (1+1) / health benefits if external costs fall (1+1)

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Jun 2021 — Q12d (8 marks) "Examine two external costs associated with aviation/air travel." (8 marks)

K2 (external costs / MSC > MPC) + App2 (aviation figures: 13m flights, carbon emissions) + An2 (carbon → global warming → flooding/drought → third-party farm income harm) + An2 (noise pollution → third parties near airports: sleep disruption, health costs) + Eval2 (external costs must be balanced with private benefits of aviation / difficult to measure)

Key data: 13 million airplane flights. Carbon emissions from aviation rising. Third parties: coastal communities, farmers.

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Oct 2021 — Q12d (8 marks) "Examine two effects of the indirect tax on using mobile internet data." (8 marks)

K2 (indirect tax / supply shifts left) + App2 (mobile data figures from extract) + An2 (price rises → quantity demanded falls → consumer surplus falls) + An2 (government revenue earned / external costs corrected) + Eval2 (PED for mobile data may be inelastic / regressive)

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Jan 2022 — Q12d (8 marks) "Examine two external costs associated with the production of clothing." (8 marks)

Mark scheme (confirmed): K2 = external costs definition (1+1) | App2 = carbon emissions / waste water from clothing production (1+1) | An2 = carbon → global warming → sea level rises → flooding of coastal communities (1+1) / waste water → river contamination → illness (1+1) | Eval2 = difficulty to quantify / costs emerge in long run / external benefits also exist (1+1) Examiner: "Candidates did very well at making explicit reference to the data in terms of waste water and carbon emissions. What was less well done was the analysis of how third parties were affected."

Key data: Clothing production generates substantial waste water and carbon emissions (figures in Extract B of Jan 2022 paper).

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Jun 2022 — Q12d (8 marks) "Examine two external costs associated with the production of salt." (8 marks) Context: salt production / health context. K2 + App2 (salt production figures) + An2 (pollution to waterways / third-party health costs) + Eval2

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Oct 2022 — Q12d (8 marks) "Examine two likely effects of excess demand for semiconductors." (8 marks)

Mark scheme (confirmed): K2 = define excess demand (1+1) | App2 = reference to: falling revenue / shortage of cars / used car prices doubling / manufacturers removing features / fewer cars produced (1+1) | An2 = removing features reduces quality → lower demand for new cars (1+1) / shortage → prices rise → consumer surplus falls (1+1) | Eval2 = depends on duration of excess demand / alternative supply sources Examiner: "The weakness in responses was the development of effects in terms of analysis. Evaluation when offered focused on [the duration and alternatives]."

Key data: Semiconductor shortage caused car manufacturers to remove features and reduce output. Used car prices doubled.

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Jan 2023 — Q12d (6 marks — SWAPPED to 6-mark) "Analyse two reasons why house prices increased between March 2020 and March 2021." Illustrate with a supply and demand diagram. (6 marks — this was Q12b in some versions / Q12d in others)

Mark scheme (confirmed): K2 = diagram original + final equilibrium | An2 = increasing real incomes / above average economic growth (1) + low base interest rates 0.25% / cheap to borrow (1) + immigration following global health crisis (1) | App: D shifts right (1) + NZ house prices rose 15.7% / average NZ$925,000 (1)

Key data: NZ house prices +15.7%. Average price NZ$925,000. Interest rates 0.25%. Note: supply not shifting here — demand-only question. Final equilibrium: higher price AND higher quantity (D shift only).

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Jun 2023 — Q12d (6 marks — SWAPPED) "Analyse one demand reason and one supply reason why the price of [EU aviation/carbon market product] changed." Illustrate with a supply and demand diagram. (6 marks) Context: aviation carbon market / EU context.

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Oct 2023 — Q12d (8 marks — standard) "Examine two effects of an indirect tax on [fertiliser/agricultural product]." (8 marks) Context: fertiliser market — same as Q12c context. K2 (indirect tax / supply shifts left) + App2 (fertiliser price data from extract) + An2 (price rises / quantity falls / external costs reduce) + Eval2 (PED may be inelastic / government failure if tax too high)

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Jan 2024 — Q12d (6 marks — SWAPPED) "Analyse one demand reason and one supply reason why the price of chicken increased by 147% between May 2020 and May 2022." Illustrate with a supply and demand diagram. (6 marks)

Mark scheme (confirmed): K2 = original equilibrium (1) + final higher equilibrium with both shifts (1) | An: demand = chicken became more popular / healthier option than other meats (1) | supply = 20% increase in cost of chicken feed / outbreak of bird flu / 140 million chickens globally could not be sold for consumption (1) | App: D shifts right (1) + S shifts left (1) + chicken price $1.50/kg (May 2020) → ~$3.70/kg (May 2022) (1)

Key data: Chicken $1.50 → $3.70/kg (+147%). Demand: health preference shift. Supply: feed costs +20%, bird flu destroying 140m chickens. Both shifts on same diagram — final equilibrium mark requires this.

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Jun 2024 — Q12d (6 marks — SWAPPED) "Analyse one demand reason and one supply reason why the price of uranium increased." Illustrate with a supply and demand diagram. (6 marks) Context: uranium/nuclear market.

Mark scheme: K2 = diagram original + final higher equilibrium | An: demand = rising gas prices → substitution to nuclear / international net-zero agreements / speculators buying uranium (1) | supply = French nuclear issues / Kazakhstan shipping problems / Canada mine output fell 9% (1) | App: uranium price rose 25% from speculative demand (1) + D right / S left on diagram (1)

Key data: Uranium price +25% (speculative demand). Supply: France critical chemicals shortage; Kazakhstan shipping; Canada mines −9%.

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Oct 2024 — Q12d (6 marks — SWAPPED) "Examine two likely effects of an indirect tax on [uranium/nuclear energy market]." (Note: this was Q12d as 6 marks in some versions of Oct 2024)

Mark scheme (confirmed): K2 = indirect tax effects: price increase / quantity decrease / consumer surplus decrease / producer surplus decrease (1+1) | App2 = uranium price figures / tax data from extract (1+1) | An2 = mechanism per effect (1+1) | Eval2 (if 8-mark version) = PED inelastic → limited quantity reduction / regressive (1+1)

Examiner (Oct 2024 Q12d): "Most referred to the price increase, quantity decrease, consumer surplus decrease, producer [surplus decrease]."

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Jan 2025 — Q12d (8 marks — standard) "Examine two effects of the Government of Ghana's decision to end the subsidies paid to cocoa farmers." (8 marks)

Mark scheme (verbatim, confirmed): K+An = farmers discouraged from growing cocoa as costs of production increase (1+1) / decreased cocoa output may result in decreased employment (1+1) / reduces use of fertiliser. As output decreases helping to reduce external costs (1+1) / higher cocoa prices → decreased consumer surplus (1+1) / diagram showing leftward supply shift (1+1) / farmers reduce investment (1+1) / reduced opportunity cost. funds used for healthcare/education (1+1) | App = $200 million in 2019 / $400 million in 2020 (1+1) | Eval = $400 million removed → substantial fall in CS/PS (1+1) / farmers dependent on subsidies — substantial income problem (1+1) / removal might promote investment to reduce costs (1+1) / depends on PED for cocoa — if inelastic, price rise greater (1+1)

Key data: Ghana subsidy $200m (2019) → $400m (2020). Subsidy ended 2023. Cocoa PES short-run +0.07 / long-run +0.57. Examiner: "Unfortunately many misinterpreted the question and talked about the introduction of a subsidy rather than the removal."

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Jun 2025 — Q12d (8 marks) "Examine two likely effects of an indirect tax on [sugar/health product]." (8 marks) Context: sugar market / health externality. K2 + App2 (sugar figures from extract) + An2 (price rises / quantity falls / external costs reduce) + Eval2 (PED inelastic / regressive concern)

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Oct 2025 — Q12d (8 marks) "Examine two external costs associated with the production of [chemical/industrial product]." (8 marks) Context: industrial/chemical production. K2 (external costs / MSC > MPC) + App2 (pollution data from extract) + An2 (contamination → third-party harm mechanism) + Eval2 (depends on scale / external benefits of production)

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Q12c/Q12d TOPIC FREQUENCY ANALYSIS

Pattern: The 6-mark question is almost always a supply/demand price change analysis requiring a diagram with both shifts. The 8-mark question rotates between: external costs (most common), PES/PED elasticity examination, indirect tax effects, and subsidy effects.

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#PART 4 — SECTION D QUESTION BANK (Q13 / Q14)

#ALL CONFIRMED ESSAY QUESTIONS — EXACT WORDING

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#PART 5 — APPLICATION DATA BANK

Real figures from confirmed WEC11 past paper extracts — usable as own-context application:

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#PART 6 — SECTION B MODEL ANSWER BANK

#MODEL ANSWERS — FOUR TYPES

TYPE A — DRAW MINIMUM PRICE (4/4):

Q: "Draw a diagram to show the effect of a minimum price for milk set above the equilibrium."

Elements required (from mark scheme — all must be present):

1. Supply curve upward sloping, demand curve downward sloping ← K mark
2. Horizontal minimum price line drawn ABOVE Pe ← App mark
3. At Pmin: new Qs (supply extends right) and new Qd (demand contracts left) labelled ← App mark
4. Surplus/excess supply labelled as Qs − Qd ← App mark

Zero written text needed. Four elements = 4/4.

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TYPE B — EXPLAIN PED FACTOR (4/4):

Q: "With reference to the data, explain one factor that is likely to influence the PED for energy."

Model 4/4 answer: "Price elasticity of demand measures the responsiveness of quantity demanded to a change in price (%ΔQd / %ΔP). [K ✓] The data shows energy PED in Australia is −0.04.. highly inelastic, with all four countries showing values between 0 and −1. [App ✓] Energy is a necessity — households require electricity and heating regardless of price changes, meaning there are no close substitutes available. [An1 ✓] Therefore, when the price of energy rises, consumers have very limited ability to reduce their consumption — a 1% price rise leads to only a 0.04% fall in quantity demanded in Australia, confirming the inelastic relationship. [An2 ✓]"

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TYPE C — CALCULATE YED (4/4):

Q: "Calculate the income elasticity of demand for [product] using the data provided."

Model 4/4 working: Step 1: Write the formula: YED = % change in Qd / % change in income ← K mark Step 2: Calculate % change in income = [(Y2 − Y1)/Y1] × 100 ← working shown Step 3: Calculate % change in Qd = [(Q2 − Q1)/Q1] × 100 ← working shown Step 4: YED = Step 3 / Step 2 = [answer] ← answer, no % sign ← App marks

Common errors costing marks:

• Inverting: income / Qd instead of Qd / income → wrong answer → max 2/4
• % sign after YED value → max 3/4
• Not showing working → if wrong answer, 0/4

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TYPE D — EXPLAIN MORAL HAZARD (4/4):

Q: "Explain why the example (insured people having more hospital visits) is an example of moral hazard."

Model 4/4 answer: "Moral hazard occurs when one party takes on greater risk because the costs of that risk are borne by another party. [K ✓] The data shows that insured individuals had 32% more hospital admissions than uninsured, confirming the behavioural change. [App ✓] With health insurance, the financial cost of illness and injury falls on the insurer rather than the insured. the effective price of taking risks (poor diet, less exercise, delaying medical check-ups) falls to zero for the insured individual. [An1 ✓] As a result, insured people take greater health risks than they would under full-cost exposure, generating more hospital visits than actuarially expected — confirming moral hazard has occurred. [An2 ✓]"

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#PART 7 — MCQ TOPIC-FREQUENCY TABLE

Topics most frequently tested in Section A across all 21 series:

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#REFERENCE CARD — QUESTION VAULT NAVIGATION

HOW TO USE THIS VAULT:
1. Find your series (year + month)
2. Check Q12c/Q12d mark allocation — it rotates
3. Note the extract commodity → your diagram type
4. Find the App mark figures for that series
5. Use CODEX · Application Bank for confirmed data

ROTATION PATTERN (Q12c/Q12d marks):
Most series: Q12c = 6mk, Q12d = 8mk
Some series: SWAPPED — always check brackets

TOP PREDICTED 2026 TOPICS:
🔴 Maximum/minimum price (7-series gap)
🔴 PES inelastic (4-series gap)
🟡 Market failure housing (5-series gap)

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VERIDIAN WEC11 · CODEX SERIES · THE QUESTION VAULT