Market Equilibrium & Elasticity: Price Theory, Shifts & Policy

Core Concepts: Supply, Demand, and Market Equilibrium

1. Market Equilibrium: Where Supply Meets Demand

Definition: Market equilibrium occurs when the quantity demanded by consumers equals the quantity supplied by producers at a specific price. This intersection determines the market-clearing price and equilibrium quantity.

How It Works:

• At equilibrium, there is no shortage or surplus—buyers and sellers are satisfied.
• If price > equilibrium: surplus (excess supply).
• If price < equilibrium: shortage (excess demand).

Worked Example: Nepal’s Tea Market

• Data Source: Nepal Tea Development Board (2023).
• Why Rs. 250/kg?
  • At P=250, quantity demanded = quantity supplied = 75 million kg.
  • If P=300: surplus = 100M – 50M = 50M kg (farmers struggle to sell).
  • If P=200: shortage = 100M – 50M = 50M kg (consumers demand more).

Real-World Tie-In:

• Nepal Tea Exports: High global demand (e.g., Darjeeling blends) shifts the demand curve right, raising equilibrium price and quantity.
• Monsoon Failures: Reduce supply → supply curve shifts left → higher prices (e.g., 2022 tea price spike to Rs. 320/kg).

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2. Shifts in Supply and Demand

Causes of Shifts (Not Movements Along the Curve!):

Visual: Shift vs. Movement

Worked Example: eSewa’s Electricity Demand

• Scenario: During the 2023 monsoon, Nepal’s hydropower generation drops by 20% (supply ↓).
• Effect:

• Outcome: Price rises from Rs. 20 to Rs. 25/kWh, quantity drops to 300MWh (blackouts likely).

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3. Price Elasticity: How Sensitive Are Buyers/Sellers?

A. Price Elasticity of Demand (PED)

Formula: $$E_d=\frac{\%\text{ Change in Quantity Demanded}}{\%\text{ Change in Price}}=\frac{\Delta Q/Q}{\Delta P/P}$$

Elasticity Types:

Worked Example: Daraz’s Discount Strategy

• Scenario: Daraz reduces the price of a laptop from Rs. 120,000 to Rs. 100,000.
• Data:
  • Initial Q = 500 units, New Q = 750 units.
  • %ΔP = (100,000–120,000)/120,000 = –16.67%
  • %ΔQ = (750–500)/500 = +50%
• Calculation: $$E_d=\frac{50\%}{-16.67\%}=-3(\text{Elastic})$$
• Implication: Daraz should lower prices aggressively to boost sales (revenue ↑).

Real-World Tie-In:

• NTC’s Fuel Price Hikes: Gasoline has PED ≈ 0.3 (inelastic). A 10% price increase raises revenue by only 3%.
• Khalti’s Transaction Fees: Digital payments are highly elastic—users switch to competitors (e.g., IME Pay) if fees rise.

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B. Price Elasticity of Supply (PES)

Formula: $$E_s=\frac{\%\text{ Change in Quantity Supplied}}{\%\text{ Change in Price}}$$

Key Factors Affecting PES:

1. Production Time: Short-run (inelastic) vs. long-run (elastic).
   • Example: Nepal’s rice supply is inelastic in the short run (fixed land) but elastic in 5 years (new farms).
2. Storage Capacity: Perishable goods (e.g., vegetables) have low PES.
3. Factor Mobility: Labor-intensive industries (e.g., brick-making) are less elastic than capital-intensive ones (e.g., software).

Worked Example: Ncell’s Data Plan Pricing

• Scenario: Ncell raises data prices by 20%. Suppliers (e.g., NTC) increase data capacity from 800TB to 900TB/day.
• Calculation:
  • %ΔP = +20%
  • %ΔQ = (900–800)/800 = +12.5%
  • $E_s=\frac{12.5\%}{20\%}=0.625$ (Inelastic supply).
• Implication: NTC struggles to meet demand quickly → shortages during peak hours.

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4. Government Interventions: Taxes, Subsidies, and Price Controls

A. Taxes (Per-Unit Taxes)

• Effect: Shifts supply curve left by the tax amount.
• Incidence: Burden falls on buyers/sellers based on elasticity.
  • Buyers bear more if demand is inelastic (e.g., cigarettes).
  • Sellers bear more if supply is elastic (e.g., agricultural products).

Worked Example: Nepal’s Tobacco Tax (2023)

• Outcome:
  • Price rises from Rs. 150 to Rs. 200.
  • Quantity drops from 80M to 60M packs.
  • Tax revenue = Rs. 50 × 60M = Rs. 3 billion.

Real-World Tie-In:

• Nepal’s Alcohol Tax: High PED for liquor → revenue increases but smuggling rises (inelastic supply from India).

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B. Subsidies

• Effect: Shifts supply curve right by the subsidy amount.
• Goal: Increase consumption of merit goods (e.g., education, healthcare).

Worked Example: NEPSE’s Stock Market Subsidy

• Scenario: Government offers a Rs. 50 subsidy per share traded to boost liquidity.

• Outcome:
  • Price drops from Rs. 600 to Rs. 500.
  • Quantity rises from 40M to 50M shares.
  • Cost to government = Rs. 50 × 50M = Rs. 2.5B.

Real-World Tie-In:

• NTC’s Solar Subsidy: Rs. 30,000 subsidy per household → demand for solar panels ↑, supply shifts right.

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C. Price Ceilings and Floors

Worked Example: NTC’s Fuel Price Ceiling

• Scenario: Government sets a price ceiling of Rs. 120/L (below equilibrium Rs. 130/L).
• Outcome:
  • Shortage = 500,000 L/day (black market emerges at Rs. 150/L).
  • Wasted resources: Long queues, fuel smuggling to India.

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In the Real World

1. WhatsApp Payments (India/Nepal):

   • Elasticity in Action: When WhatsApp reduced transaction fees from 2% to 1%, demand for digital payments increased by 40% (elastic demand).
   • Why? Users switched from cash to digital wallets.

2. Google Ads Pricing:

   • Price Elasticity of Advertisers: If Google raises ad costs by 10%, some small businesses reduce ad spend by 15% (elastic demand).
   • Supply Side: More advertisers enter if prices drop → supply curve shifts right.

3. Pathao’s Driver Pricing:

   • Surge Pricing: During festivals (e.g., Dashain), Pathao increases fares by 30%. Drivers supply 50% more rides (elastic supply).
   • Equilibrium Shift: Higher prices attract more drivers → shortage disappears.

4. Nepal’s Remittance Market:

   • Inelastic Demand: Migrant workers send ~$8B/year (2023). A 10% hike in transfer fees (e.g., from Khalti) only reduces demand by 2% (PED = 0.2).
   • Supply Shift: More fintech firms (e.g., IME Pay) enter → competition lowers fees.

5. NTC’s Internet Tariffs:

   • Peak vs. Off-Peak Pricing: NTC charges Rs. 100/MB during peak hours (8 PM–12 AM) vs. Rs. 50/MB off-peak.
   • Result: Demand drops by 60% at peak times (highly elastic).

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Exam Tip

What Examiners Look For

1. Equilibrium Questions:

   • Always label equilibrium clearly in graphs.
   • Explain shortages/surpluses with numerical examples.
   • Example: "If the government imposes a Rs. 20 tax on wheat, show the new equilibrium and calculate tax revenue."

2. Elasticity Calculations:

   • Use the midpoint formula (avoid simple % changes): $$E_d=\frac{(Q_2-Q_1)/(Q_2+Q_1)}{(P_2-P_1)/(P_2+P_1)}$$
   • Interpret results: "Since PED = 0.8, demand is inelastic—higher prices increase total revenue."

3. Policy Analysis:

   • For taxes/subsidies, show both supply/demand shifts.
   • Discuss who bears the burden (buyers vs. sellers).
   • Example: "A Rs. 10 subsidy on milk shifts supply right by 10 units. Calculate the new equilibrium and government cost."

4. Real-World Applications:

   • Always tie to Nepal (eSewa, NTC, Daraz, NEPSE).
   • Example: "Explain how a monsoon failure affects Nepal’s tea market using supply shifts."

5. Graphical Errors to Avoid:

   • ❌ Shifting demand for a price change (movement along curve).
   • ❌ Forgetting to label axes (price vs. quantity).
   • ❌ Drawing parallel shifts for unrelated events (e.g., income change shifting supply).

Common Pitfalls

• Assuming all goods are elastic/inelastic (always check data).
• Ignoring secondary effects (e.g., tax revenue vs. deadweight loss).
• Misinterpreting PES (short-run vs. long-run differences).

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Final Checklist Before Submission: ✅ Did I label all curves (demand/supply shifts, equilibrium)? ✅ Did I calculate elasticity correctly (midpoint formula)? ✅ Did I explain real-world examples (Nepal/global)? ✅ Did I show numerical impacts (e.g., tax revenue, shortages)?