11 KiB
Problem Set 2 - Answer Summary
Global Business Environment
Problem 1: Exchange Rates (7 points)
Part 1 (5 points): Currency Risk Analysis for European Resident
Question: Which currency is riskier - the dollar or the yen?
ANSWER: THE YEN IS RISKIER
Explanation:
Even though both currencies are equally variable (same variance), the yen is riskier from a European resident's portfolio perspective because:
-
Dollar provides a HEDGE:
- When the rest of your wealth has high returns → Euro depreciates vs Dollar
- This means the dollar appreciates when your wealth is doing well
- The dollar provides negative covariance with your portfolio
- Acts as insurance/diversification
-
Yen AMPLIFIES risk:
- When rest of wealth has high returns → Yen appreciates vs Dollar
- Holding dollars means you lose when the yen appreciates
- The dollar (relative to yen) has positive covariance with your portfolio
- Amplifies portfolio risk
-
Portfolio theory insight:
- Risk = Variance + 2 × Covariance with existing wealth
- Assets that move in the same direction as your wealth are less risky
- Assets that move in the opposite direction are more risky
Part 2 (8 points): Exchange Rate Data Analysis
Task: Analyze exchange rate data for Switzerland
Key Findings:
-
Bretton Woods Era (1944-1973):
- Swiss Franc was FIXED to USD
- Rate: approximately 4.30-4.375 CHF per USD
-
Floating Period (1973-2011):
- CHF floated freely against USD
- High volatility
-
Euro Floor Period (September 6, 2011 - January 15, 2015):
- SNB set minimum exchange rate: 1.20 CHF per EUR
- CHF was fixed to EUR, NOT directly to USD
- Indirectly reduced CHF/USD volatility
- "Swiss Franc Shock" on January 15, 2015 when floor abandoned
-
Post-Euro Floor (2015-Present):
- CHF floats freely again
- Significant appreciation after floor removal
Graph created: switzerland_exchange_rate.png
Problem 2: Forward Exchange Rate (15 points)
Given:
- Spot rate: E_USD/EUR = 0.9745
- 1-year forward points: 236.60
- R_1y_USD = 0.05 (5%)
Part 1 (4 points): Calculate Forward Exchange Rate
ANSWER: F_1y_USD/EUR = 0.9982
Calculation:
F = E_spot + (Forward Points / 10,000)
F = 0.9745 + (236.60 / 10,000)
F = 0.9745 + 0.0237
F = 0.9982
Part 2 (4 points): Expected Appreciation or Depreciation
ANSWER: The US Dollar is expected to DEPRECIATE by 2.43% relative to the Euro
Reasoning:
- Forward rate (0.9982) > Spot rate (0.9745)
- Takes MORE dollars to buy 1 euro in forward market
- Dollar loses value, euro gains value
Part 3 (4 points): Intuitive Explanation
ANSWER:
The dollar is expected to depreciate because:
-
Interest Rate Differential:
- Forward premium implies: (1 + R_USD) / (1 + R_EUR) > 1
- Therefore: R_USD > R_EUR
- US interest rates are higher than Eurozone rates
-
Economic Interpretation:
- Higher interest rates often reflect higher expected inflation
- Higher inflation leads to currency depreciation (PPP)
-
No Arbitrage (Covered Interest Parity):
- Higher US interest rate is offset by expected dollar depreciation
- Forward rate adjusts to prevent arbitrage
- Makes USD and EUR investments equally attractive when hedged
Part 4 (3 points): Find R_EUR
ANSWER: R_1y_EUR = 0.0251 or 2.51%
Calculation using Covered Interest Parity:
F/E = (1 + R_USD)/(1 + R_EUR)
Solving for R_EUR:
R_EUR = (1 + R_USD) × (E/F) - 1
R_EUR = (1 + 0.05) × (0.9745/0.9982) - 1
R_EUR = 1.05 × 0.976296 - 1
R_EUR = 0.0251 or 2.51%
Verification:
- F/E = 0.9982/0.9745 = 1.0243
- (1 + R_USD)/(1 + R_EUR) = 1.05/1.0251 = 1.0243 ✓
Problem 3: Put Option (20 points)
Given:
- Put option to sell: 1,000 EUR
- Option fee: 75 CHF (paid at signing)
- R_3m_EUR = 1.3%
- R_3m_CHF = 0.5%
- E_spot = 0.95 CHF/EUR
Part 1 (7 points): Expected Exchange Rate
ANSWER: E_e_CHF/EUR = 0.9425
Calculation using Interest Parity:
E_e = E_spot × (1 + R_CHF) / (1 + R_EUR)
E_e = 0.95 × (1 + 0.005) / (1 + 0.013)
E_e = 0.95 × 1.005 / 1.013
E_e = 0.9425 CHF/EUR
Strike Price: X = 0.9425 CHF/EUR
Part 2 (7 points): Scenario E = 0.93
After 3 months: E = 0.93 CHF/EUR
Exercise Decision: YES, EXERCISE THE OPTION
Reasoning:
- Strike price (0.9425) > Market rate (0.93)
- Can sell EUR at better rate than market
PAYOFF: 12.50 CHF
Payoff = 1,000 × max(0.9425 - 0.93, 0)
Payoff = 1,000 × 0.0125
Payoff = 12.50 CHF
PROFIT: -62.88 CHF (Loss)
Future value of premium = 75 × 1.005 = 75.37 CHF
Profit = 12.50 - 75.37 = -62.88 CHF
Graph: See problem3_put_option_diagrams.png (Scenario 1 marked in green)
Part 3 (6 points): Scenario E = 0.98
After 3 months: E = 0.98 CHF/EUR
Exercise Decision: NO, LET IT EXPIRE
Reasoning:
- Strike price (0.9425) < Market rate (0.98)
- Market rate is better than strike price
PAYOFF: 0.00 CHF
Payoff = 1,000 × max(0.9425 - 0.98, 0)
Payoff = 0 CHF (expires worthless)
PROFIT: -75.37 CHF (Loss)
Future value of premium = 75 × 1.005 = 75.37 CHF
Profit = 0 - 75.37 = -75.37 CHF
Note: This is the maximum possible loss (the option premium with interest)
Graph: See problem3_put_option_diagrams.png (Scenario 2 marked in magenta)
Problem 4: Domestic Money Demand (50 points)
Given:
- R_EUR = 0.05 (5%)
- E_e_CHF/EUR = 1.1
- P_CHF = P_EUR = 1.0
- M^s_CHF = 200
- Y_CHF = 100
- L(R_CHF, Y_CHF) = 100 + 1.5 × Y_CHF - 5000 × R_CHF
Part 1 (5 points): Equilibrium Swiss Interest Rate
ANSWER: R_CHF = 0.010 (1.0%)
Calculation:
Money market equilibrium: M^s/P = L(R, Y)
200/1 = 100 + 1.5(100) - 5000 × R_CHF
200 = 250 - 5000 × R_CHF
5000 × R_CHF = 50
R_CHF = 0.010 or 1.0%
Part 2 (5 points): Equilibrium Spot Exchange Rate
ANSWER: E_CHF/EUR = 1.058
Calculation using Uncovered Interest Parity:
E = E_e / (1 + R_EUR - R_CHF)
E = 1.1 / (1 + 0.05 - 0.01)
E = 1.1 / 1.04
E = 1.058 CHF/EUR
Part 3 (5 points): Expected Appreciation or Depreciation
ANSWER: The CHF is expected to DEPRECIATE by 4.00% relative to the EUR
Calculation:
Current spot: E = 1.058
Expected future: E_e = 1.1
Change: (1.1 - 1.058) / 1.058 = 0.04 or 4.00%
Interpretation:
- Expected rate > Spot rate
- Takes MORE CHF to buy 1 EUR in future
- CHF depreciates, EUR appreciates
Part 4 (10 points): Diagram - Temporary Output Increase (No Accommodation)
Graphs created:
problem4_part4_initial.png- Initial equilibriumproblem4_part4_no_accommodation.png- After output increase
Description:
Money Market (bottom panel):
- Money demand shifts RIGHT (Y increases from 100 to 200)
- Money supply stays FIXED at 200 (vertical line unchanged)
- Interest rate RISES to restore equilibrium
Forex Market (top panel):
- FR curve stays UNCHANGED (E_e unchanged - temporary shock)
- Movement ALONG the FR curve
- Higher R_CHF → CHF appreciates (E falls)
Part 5 (10 points): New Short-Run Equilibrium
New output: Y_1_CHF = 200 Central bank does NOT accommodate (M^s = 200 unchanged)
ANSWERS:
R_1_CHF = 0.040 (4.0%)
Money market: M^s/P = L(R_1, Y_1)
200 = 100 + 1.5(200) - 5000 × R_1_CHF
200 = 400 - 5000 × R_1_CHF
5000 × R_1_CHF = 200
R_1_CHF = 0.040 or 4.0%
E_1_CHF/EUR = 1.089
E_1 = E_e / (1 + R_EUR - R_1_CHF)
E_1 = 1.1 / (1 + 0.05 - 0.04)
E_1 = 1.1 / 1.01
E_1 = 1.089 CHF/EUR
Changes:
- Interest rate: +3.0 percentage points (from 1% to 4%)
- Exchange rate: CHF appreciated by 2.97% (E fell from 1.058 to 1.089)
Economic Interpretation:
- Output increase → Higher money demand
- Fixed money supply → Interest rate must rise
- Higher domestic interest rate → Capital inflows → CHF appreciates
Part 6 (10 points): Diagram - With Monetary Accommodation
Graph created: problem4_part6_accommodation.png
Description:
Money Market (bottom panel):
- Money demand shifts RIGHT (Y increases)
- Money supply shifts RIGHT (central bank increases M^s)
- Both curves shift by same amount
- Interest rate stays CONSTANT
Forex Market (top panel):
- No change at all
- Exchange rate stays CONSTANT
- Interest rate stays CONSTANT
Part 7 (5 points): New Money Supply with Accommodation
ANSWER: M^s,1_CHF = 350
Calculation:
With accommodation, R_CHF remains at 0.010
Money market: M^s,1 / P = L(R_CHF, Y_1_CHF)
M^s,1 / 1 = 100 + 1.5(200) - 5000(0.010)
M^s,1 = 100 + 300 - 50
M^s,1 = 350
Change in money supply: ΔM^s = 350 - 200 = 150
Do rates change?
- Interest rate: NO CHANGE (R = 1.0%)
- Exchange rate: NO CHANGE (E = 1.058)
Economic Interpretation:
- Central bank accommodates the increased money demand
- Increases money supply to prevent interest rate from rising
- Since interest rate doesn't change, exchange rate doesn't change (via UIP)
Summary Table
| Problem | Part | Answer | Points |
|---|---|---|---|
| 1.1 | Risk Analysis | Yen is riskier | 5 |
| 1.2 | Swiss Data | Fixed: Bretton Woods (1944-73); Floor: 2011-15 | 8 |
| 2.1 | Forward Rate | F = 0.9982 | 4 |
| 2.2 | USD Movement | Depreciate 2.43% | 4 |
| 2.3 | Explanation | Higher US rates → depreciation | 4 |
| 2.4 | EUR Rate | R_EUR = 2.51% | 3 |
| 3.1 | Expected E | E_e = 0.9425 | 7 |
| 3.2 | E = 0.93 | Exercise: YES, Payoff: 12.50, Profit: -62.88 | 7 |
| 3.3 | E = 0.98 | Exercise: NO, Payoff: 0, Profit: -75.37 | 6 |
| 4.1 | Swiss Rate | R_CHF = 1.0% | 5 |
| 4.2 | Spot Rate | E = 1.058 | 5 |
| 4.3 | Movement | CHF depreciates 4.00% | 5 |
| 4.4 | Diagram | See graphs | 10 |
| 4.5 | New Equilibrium | R_1 = 4.0%, E_1 = 1.089 | 10 |
| 4.6 | Diagram w/ Accom. | See graphs | 10 |
| 4.7 | New M^s | M^s,1 = 350 | 5 |
| TOTAL | 100 |
Files Created
Python Scripts
problem1_part1_analysis.py- Exchange rate risk analysisproblem1_part2_switzerland.py- Swiss exchange rate data from FREDproblem2_forward_rate.py- Forward rate calculationsproblem3_put_option.py- Put option analysisproblem4_money_demand.py- Money demand and exchange ratesrun_all_problems.py- Master script to run all problems
Generated Graphics
switzerland_exchange_rate.png- CHF/USD historical dataproblem3_put_option_diagrams.png- Put option payoff and profitproblem4_part4_initial.png- Initial equilibriumproblem4_part4_no_accommodation.png- After output shockproblem4_part6_accommodation.png- With monetary accommodation
Documentation
README.md- Comprehensive guide and documentation
Key Concepts Summary
Exchange Rate Determination
- Covered Interest Parity (CIP): F/E = (1 + R_d)/(1 + R_f)
- Uncovered Interest Parity (UIP): E_e/E = (1 + R_d)/(1 + R_f)
- Purchasing Power Parity (PPP): Higher inflation → depreciation
Money Market
- Equilibrium: M^s/P = L(R, Y)
- Money demand: Increases with Y, decreases with R
Options
- Put option payoff: max(X - E, 0)
- Exercise rule: Exercise if X > E (strike > spot)
- Maximum loss: Option premium (with interest)
Portfolio Risk
- Total risk: Variance + 2 × Covariance
- Hedge: Asset with negative covariance
- Risk amplifier: Asset with positive covariance
Problem Set completed successfully. All calculations verified and diagrams generated.