Tariff & Quota Analysis (HL)
Advanced trade policy analysis for higher level economics with welfare effects, terms of trade, and economic integration concepts.
HL OnlyAbout this section: Tariffs and quotas are key protectionist policies examined in IB Economics HL Extension. These questions develop skills in calculating welfare effects, analyzing price mechanisms, understanding terms of trade dynamics, and evaluating the Marshall-Lerner condition and J-curve effect. All questions require step-by-step calculations and economic reasoning.
Question 1: Tariff Analysis — Welfare Effects
20 marksContext: A country imports steel. The government imposes a tariff of $20 per tonne. Use the following data:
| Scenario | World Price (Pw) | Domestic Demand | Domestic Supply | Imports |
|---|---|---|---|---|
| Before Tariff | $100 | 500 tonnes | 200 tonnes | 300 tonnes |
| After Tariff (+$20) | $120 (P = Pw + Tariff) | 450 tonnes | 280 tonnes | 170 tonnes |
Draw a tariff diagram. Axes: Price (y-axis), Quantity (x-axis). Curves: downward-sloping domestic Demand (D), upward-sloping domestic Supply (S). Horizontal world supply line at Pw = $100. After tariff: new horizontal line at Pw + tariff = $120. Before tariff: domestic demand = 500, domestic supply = 200, imports = 300. After tariff: demand falls to 450, supply rises to 280, imports fall to 170.
Label these areas:
- (a) Consumer surplus loss = trapezoid between $100 and $120, from Q=0 to Q=500/450.
- (b) Producer surplus gain = trapezoid between $100 and $120, from Q=0 to Q=200/280.
- (c) Government revenue = rectangle: height $20, width = imports (170).
- (d) Two deadweight loss triangles: production distortion triangle (between domestic supply at Pw and Pw+t, from Q=200 to Q=280) and consumption distortion triangle (between demand at Pw and Pw+t, from Q=450 to Q=500).
Model Answer (a) - Change in Consumer Surplus
Consumer surplus is the area under the demand curve above the price.
Before tariff: Consumers buy 500 tonnes at P = $100
After tariff: Consumers buy 450 tonnes at P = $120
Loss in consumer surplus:
Rectangle = 450 × $20 = $9,000
Triangle = 0.5 × 50 × $20 = $500
Total loss = $9,500
Model Answer (b) - Change in Producer Surplus
Producer surplus is the area above the supply curve below the price.
Rectangle = 200 × $20 = $4,000
Triangle = 0.5 × 80 × $20 = $800
Total gain = $4,800
Model Answer (c) - Government Tariff Revenue
Tariff revenue = Tariff per unit × Quantity of imports
$20 × 170 = $3,400
Model Answer (d) - Deadweight Loss
Production distortion: 0.5 × 80 × $20 = $800
Consumption distortion: 0.5 × 50 × $20 = $500
Total Deadweight Loss = $1,300
Model Answer (e) - Verification
$9,500 = $4,800 + $3,400 + $1,300 = $9,500 ✓
Model Answer (f) - Evaluation of Tariffs
For: Infant industry protection, countervailing dumping, employment, strategic industries.
Against: DWL of $1,300, consumer harm ($9,500 loss), misallocation of resources, retaliation risk, alternatives (subsidies, adjustment assistance) more efficient.
Conclusion: Tariffs create welfare losses unless justified by market failures. Limited, temporary tariffs with adjustment assistance may be equitable.
Question 2: Quota Analysis
15 marksContext: A country imposes an import quota on rice. Use the data below:
| Scenario | World Price | Domestic Demand | Domestic Supply | Imports |
|---|---|---|---|---|
| Before Quota | $50 | 400 tonnes | 150 tonnes | 250 tonnes |
| After Quota (100 tonnes) | $50 (world) | 350 tonnes | 200 tonnes | 100 tonnes (quota) |
Note: With the quota, the domestic price rises to $70 to clear the market with only 100 tonnes of imports available.
Draw a quota diagram. Show: domestic S curve, D curve, world price Pw = $50, and a new effective supply curve S+quota. The new price rises to $70. The quota rent rectangle (equivalent to tariff revenue) goes to whoever holds the import licences. Label: consumer surplus loss, producer surplus gain, quota rent rectangle, and two DWL triangles.
Model Answer (a) - Tariff vs. Quota
Tariff: Tax on imports; operates through PRICE; quantity flexible; government gets revenue.
Quota: Hard quantity limit; operates through QUANTITY; price adjusts; quota rent goes to license holders.
Key difference: Tariff controls price, quota controls quantity.
Model Answer (b) - Welfare Effects of Quota
CS loss: Rectangle 350 × $20 = $7,000; Triangle 0.5 × 50 × $20 = $500; Total = $7,500
PS gain: Rectangle 150 × $20 = $3,000; Triangle 0.5 × 50 × $20 = $500; Total = $3,500
Quota rent: ($70 - $50) × 100 = $2,000
Model Answer (c) - Deadweight Loss
Production DWL: 0.5 × 50 × $20 = $500
Consumption DWL: 0.5 × 50 × $20 = $500
Total DWL = $1,000
Model Answer (d) - Efficiency Comparison
Tariffs are MORE efficient: They adjust automatically to price changes. Quotas are rigid and create rent-seeking.
Quotas disadvantages: If world prices fall, quota becomes restrictive. Quota rents may be captured by special interests. WTO prefers tariffs.
Question 3: Terms of Trade
15 marksContext: Country X exports manufactured goods and imports raw materials. Use the price indices below:
| Year | Export Price Index | Import Price Index |
|---|---|---|
| Year 1 | 100 | 100 |
| Year 2 | 110 | 105 |
| Year 3 | 115 | 120 |
| Year 4 | 108 | 125 |
Index-based diagram: Terms of Trade = (Export Price Index / Import Price Index) x 100. A diagram could show both indices over time as a line graph. Plot Years on x-axis, Price Index on y-axis. Show how export and import prices diverge, with imports rising faster, causing ToT to deteriorate.
Model Answer (a) - Terms of Trade Calculation
Year 1: (100/100) × 100 = 100
Year 2: (110/105) × 100 = 104.76
Year 3: (115/120) × 100 = 95.83
Year 4: (108/125) × 100 = 86.40
Model Answer (b) - Trend Analysis
Pattern: Improvement Year 2 (104.76), then deterioration Years 3-4 (95.83 → 86.40).
Causes: Export prices weakening (115 → 108); import prices surging (105 → 125). Commodity boom increases raw material costs while manufactured exports face competition.
Model Answer (c) - Factors Causing Deterioration
Factor 1: Commodity Price Boom: Global demand for raw materials surges (China/India); supply is price-inelastic. Import prices rise sharply.
Factor 2: Loss of Competitiveness: Manufactured goods face competition; to maintain export volumes, prices cut. Export price index falls while imports remain inelastic.
Model Answer (d) - Is ToT Improvement Always Beneficial?
Generally YES: Better purchasing power and real income.
Caveats: Dutch Disease (currency appreciation, sector collapse); composition matters; short-term gains may mask long-term decline. ToT must be sustainable.
Question 4: The Marshall-Lerner Condition and the J-Curve
15 marksContext: Country Y's currency depreciates by 15%. Use the elasticity data below:
| Elasticity | Short-run | Long-run |
|---|---|---|
| PED (Exports) | 0.6 | 0.8 |
| PED (Imports) | 0.3 | 0.7 |
Initial: Exports = $100bn, Imports = $100bn (balanced trade).
Draw the J-Curve diagram. Axes: Current Account Balance (y-axis, 0 baseline), Time (x-axis). Start at 0 (balanced). After depreciation, current account dips down initially (short-run worsening) because volumes haven't adjusted but import prices are higher (PED exports + PED imports < 1). Over time, elasticities increase, export volumes rise, import volumes fall, and current account improves (upstroke of J). Label short-run deterioration and long-run improvement.
Model Answer (a) - Marshall-Lerner Condition
PED(Exports) + PED(Imports) > 1
Depreciation improves current account if elasticities are high enough. Quantity responses must outweigh price changes.
Model Answer (b) - Short-run Analysis
Marshall-Lerner test: 0.6 + 0.3 = 0.9 < 1 NOT MET
Exports: (1.09) × (0.85) × $100 = $92.65bn
Imports: (0.955) × (1.15) × $100 = $109.83bn
Current account = -$17.18bn WORSENS
Model Answer (c) - Long-run Analysis
Marshall-Lerner test: 0.8 + 0.7 = 1.5 > 1 MET
Exports: (1.12) × (0.85) × $100 = $95.2bn
Imports: (0.895) × (1.15) × $100 = $102.93bn
Current account = -$7.73bn IMPROVES from -$17.18bn
Model Answer (d) - J-Curve Effect
Short-run: Import volumes fixed (contracts locked); import bill rises. Export volumes rise slowly; buyers need time. Current account deteriorates sharply (-$17.18bn).
Long-run: Consumers adjust; export demand increases elastically. Import demand falls elastically. Marshall-Lerner takes hold. Current account improves (-$7.73bn).
J-shape: Dip down (short-run deterioration), then rise (long-run improvement). Policymakers must be patient.
Model Answer (e) - Effectiveness of Depreciation
Advantages: Automatic adjustment; long-run effectiveness if M-L holds; improves competitiveness.
Limitations: J-curve delays gains; depends on elasticities; inflation effects; foreign debt burden worsens; doesn't fix structural issues.
Conclusion: Effective if M-L met and policymakers patient. Works best with structural reforms.
Question 5: Economic Integration and Trade Creation/Diversion
10 marksContext: Three countries (A, B, C) produce widgets. Country A forms a customs union with Country B (removing all tariffs between them, keeping 30% tariff on Country C imports). Analyse the trade effects:
| Country | Cost per Widget | With A's 30% Tariff on C | After Customs Union |
|---|---|---|---|
| A (home) | $12 | $12 | $12 |
| B (union partner) | $10 | $13 (tariff) | $10 (no tariff) |
| C (external) | $8 | $10.40 (tariff) | $10.40 (tariff remains) |
Draw a trade effects diagram. Before union: A imports from C at $10.40 (cheapest after tariff). After union with B: tariff removed on B's goods (price = $10). A switches from C to B. This is TRADE DIVERSION because most efficient producer globally is C ($8) but A now imports from less efficient B ($10). Show costs: C's true cost $8 < B's cost $10, but C+tariff $10.40 > B's cost $10 (no tariff in union). Welfare loss = $2/widget, but price reduction $10.40 → $10 = $0.40/widget gain. Net effect depends on volumes.
Model Answer (a) - Pre-Union Import Source
Prices A faces:
- A: $12
- B: $10 × 1.30 = $13
- C: $8 × 1.30 = $10.40
A imports from C at $10.40 (cheapest)
Model Answer (b) - Post-Union Import Source
Prices A faces:
- A: $12
- B: $10 (no tariff)
- C: $10.40 (tariff unchanged)
A imports from B at $10 (cheapest)
Model Answer (c) - Trade Creation vs. Diversion
Definitions:
Trade Creation: imports from lower-cost union partner, replacing inefficient domestic production (beneficial).
Trade Diversion: imports from higher-cost union partner instead of cheapest external source (harmful).
This is TRADE DIVERSION: A switched from C ($8 true cost) to B ($10 cost). Global efficiency loss = $2/widget.
Model Answer (d) - Overall Welfare Evaluation
Static (short-run): Welfare-reducing due to trade diversion. A imports from less efficient B instead of cheapest supplier C. Social cost worsens.
Dynamic (long-run) benefits: B may achieve economies of scale, reducing costs. Innovation and competition may improve. Investment and technology transfer increase.
Conclusion: Short-run losses may be outweighed by long-run dynamic gains. Many real-world unions (MERCOSUR, ECOWAS) accept this tradeoff.
Tips for Success
- Master the welfare framework: Calculate consumer surplus loss, producer surplus gain, tariff revenue, and deadweight loss.
- Understand price vs. quantity mechanisms: Tariffs raise prices; quotas restrict quantities.
- Apply Marshall-Lerner correctly: Elasticities must sum to > 1 for depreciation to improve current account.
- Explain the J-curve: Current account worsens initially, improves long-run.
- Distinguish trade creation from diversion: Creation beneficial, diversion harmful.
- Show all working: Marks reward methodology and step-by-step reasoning.
- Evaluate beyond static analysis: Consider dynamic effects, real-world complications.