Main Issues
- Why does international asset pricing differ from domestic?
- Computing returns across currencies: the domestic investor’s perspective
- The CAPM and the tangency portfolio argument
- Why CAPM breaks internationally: which market portfolio? FX risk?
- The 2×2 ICAPM framework with worked examples
- Currency risk factors: carry, dollar, momentum, volatility
- Connection: this gives us the discount rate for APV Step 1 (Lecture 10)
Returns in International Markets
Computing Returns in Domestic Currency
A US investor buying German stocks earns two components:
- Local return (\(r_{local}\)): the DAX return in EUR
- FX return (\(\Delta s\)): the change in EUR/USD
Exact formula: \[r_{domestic} = (1 + r_{local})(1 + \Delta s) - 1\]
Approximation (for small returns): \[r_{domestic} \approx r_{local} + \Delta s\]
Key principle: We always evaluate returns from the perspective of the domestic investor
Example: Local Return + FX Return
Variance of Domestic Returns
The variance of the domestic return has three components:
\[\text{Var}(r_{dom}) = \text{Var}(r_{local}) + \text{Var}(\Delta s) + 2\text{Cov}(r_{local}, \Delta s)\]
Key implication: Even a risk-free foreign bond is risky to a domestic investor!
- German 1-year T-bill: riskless for a German investor
- For a US investor: \(\text{Var}(r_{dom}) = 0 + \text{Var}(\Delta s) + 0 = \text{Var}(\Delta s)\)
- EUR/USD can move 10–15% per year — far from riskless!
Unless PPP holds perfectly (which it doesn’t — Lecture 3)
Why This Matters for Asset Pricing
- Investors in different countries see different risk–return profiles for the same asset
- This violates the homogeneous expectations assumption of the CAPM
- The US investor’s tangency portfolio differs from the German investor’s
- They disagree on which assets are “risky”
- We need a model that accounts for this heterogeneity
Two ingredients needed:
- Which market portfolio to use (financial integration)
- Whether FX risk is separately priced (product market integration)
Mean-Variance Optimization
Tangency Portfolio = Market Portfolio
Homogeneous opportunities: all investors face the same assets and risk-free rate
Homogeneous expectations: all investors agree on means, variances, covariances
\(\Rightarrow\) Everyone holds the same tangency portfolio as their risky allocation
Equilibrium: demand = supply
\(\Rightarrow\) Tangency portfolio (demanded) = Market portfolio (supplied)
This is the key insight of the CAPM: in equilibrium, the market portfolio is the tangency portfolio
The CAPM Equation
Risk is measured relative to the market portfolio:
\[\beta_j = \frac{\text{Cov}({\widetilde{r}}_j, {\widetilde{r}}_M)}{\text{Var}({\widetilde{r}}_M)}\]
The CAPM:
\[E[{\widetilde{r}}_j] = r_f + \beta_j \times \underset{\color{#2E86AB}{\small\textbf{market risk premium}}}{\bbox[#dbeafe,5px,border:1px solid #2E86AB]{\;(E[{\widetilde{r}}_M] - r_f)\;}}\]
- \(\beta = 0\): earn the risk-free rate (no systematic risk)
- \(\beta = 1\): earn the market return
- \(\beta > 1\): amplified market risk, higher expected return
CAPM: Numerical Examples
Suppose the market premium is 5% and \(r_f = 2\%\):
| 0 |
2% |
Risk-free rate |
| 1 |
7% |
Market return |
| 2 |
12% |
Aggressive (amplified risk) |
| \(-0.5\) |
\(-0.5\%\) |
Hedge asset (insurance) |
- In practice: beta services provide estimates for industries/firms
- But they typically assume the CAPM holds country-by-country with the domestic market
- Is this the right benchmark? \(\rightarrow\) Not always!
Why CAPM Breaks Internationally
Problem 1: Financial Integration
A country is financially integrated if:
- Firms borrow and raise funds in international capital markets
- Investors directly invest across borders
- Cross-border capital flows are substantial
If integrated (US, UK, Germany, Japan): benchmark = world market portfolio
If segmented (some EM with capital controls): benchmark = domestic market portfolio
Practical proxy for world market: Vanguard Total World Stock ETF (VT), FTSE Global All Cap Index, expense ratio 10bp
Venus and Mars: Segmented Markets
Imagine two planets with the same currency (no FX risk for now):
| Risk-free rate |
5% |
5% |
| Market volatility |
30% |
30% |
| Risk aversion (\(\gamma\)) |
0.45 |
0.65 |
Expected returns on domestic markets:
\[\mu_M = 5\% + 0.45 \times 0.30^2 = 9.05\%\] \[\mu_V = 5\% + 0.65 \times 0.30^2 = 10.85\%\]
Sharpe ratios: 0.135 (Mars) vs. 0.195 (Venus)
Segmented: Cost of Capital Differs!
A project on Venus with \(\beta = 0.75\):
Venus investor (uses Venus market, premium = 5.85%):
\[E[r] = 5\% + 0.75 \times 5.85\% = 9.39\%\]
Mars investor (uses Mars market, premium = 4.05%):
\[E[r] = 5\% + 0.75 \times 4.05\% = 8.04\%\]
Same project, same beta, DIFFERENT cost of capital!
\(\Rightarrow\) When markets are segmented, who you are matters
Integrated: Cost of Capital Is the Same
Now open the border — markets are financially integrated:
| Aggregate risk aversion (\(\gamma\)) |
0.53 |
| World market return |
7.38% |
| World market volatility |
21.21% |
Same project on Venus, \(\beta = 0.75\):
\[E[r] = 5\% + 0.75 \times 2.38\% = 6.79\%\]
\(\Rightarrow\) Same for both investors! Who you are doesn’t matter. Only systematic risk (relative to the world) is priced.
Problem 2: Exchange Rate Risk
Now add different currencies. Ignore FX risk?
- If product markets are integrated (PPP holds):
- No real exchange rate risk \(\rightarrow\) single-factor CAPM suffices
- Just pick the right market portfolio (world or domestic)
- If product markets are not integrated (PPP fails):
- Investors see different real returns on the same asset
- A UK investor sees the US T-bill as risky; a US investor sees it as risk-free
- \(\rightarrow\) Violation of homogeneous expectations
\(\Rightarrow\) Need an additional factor for FX risk
The Two-Factor International CAPM
When PPP fails and financial markets are integrated:
\[E[{\widetilde{r}} - r] = \underset{\color{#2E86AB}{\small\textbf{world market risk}}}{\bbox[#dbeafe,5px,border:1px solid #2E86AB]{\;\beta_W \times (E[{\widetilde{r}}_W] - r)\;}} \;+\; \underset{\color{#D45500}{\small\textbf{exchange rate risk}}}{\bbox[#fce7d6,5px,border:1px solid #D45500]{\;\beta_s \times (E[{\widetilde{s}}] + r^{FC} - r)\;}}\]
where:
- \(\beta_W = \frac{\text{Cov}(\widetilde{r}, {\widetilde{r}}_W)}{\text{Var}({\widetilde{r}}_W)}\) — world market beta
- \(\beta_s = \frac{\text{Cov}(\widetilde{r}, \widetilde{s})}{\text{Var}(\widetilde{s})}\) — exchange rate beta
\(\Rightarrow\) Two sources of systematic risk, two risk premia
Three Key Questions
Before applying the 2×2 framework, consider:
Q1: What if UIP holds (\(E[{\widetilde{s}}] + r^{FC} - r = 0\))?
- FX risk premium is zero \(\rightarrow\) \(\beta_s\) drops out; single-factor CAPM suffices
Q2: What if the carry trade is profitable?
- FX risk premium \(\neq 0\) \(\rightarrow\) \(\beta_s\) matters; sign depends on FX correlation
Q3: What if the firm hedges all its currency exposure?
- \(\beta_s = 0\) by construction \(\rightarrow\) FX term drops out
- Another reason hedging can be valuable (Lecture 6)
The Four Cases
Case 1: Both Integrated (e.g., within EU)
Product markets integrated (PPP holds) + Financial markets integrated
- Use your home currency risk-free rate
- Use a global index as proxy for market portfolio
- No FX risk — PPP eliminates real exchange rate risk
- Run a univariate regression to estimate \(\beta_W\)
\[E[\widetilde{r}] = r_f + \beta_W \times (E[{\widetilde{r}}_W] - r_f)\]
This is just the standard CAPM with a global market portfolio
Case 2: PM Segmented, FM Integrated (e.g., UK–US)
Product markets segmented (PPP fails) + Financial markets integrated
- Use your home currency risk-free rate
- Use a global index as proxy for market portfolio
- FX risk matters — PPP deviations create real exchange rate risk
- Run a multivariate regression for \(\beta_W\) and \(\beta_s\)
\[E[{\widetilde{r}}] = r_f + \beta_W(E[{\widetilde{r}}_W] - r_f) + \beta_s(E[{\widetilde{s}}] + r^{FC} - r_f)\]
If the company is perfectly hedged: \(\beta_s = 0\) \(\rightarrow\) reduces to Case 1
Case 3: PM Integrated, FM Segmented (e.g., EU–Greece pre-crisis)
Product markets integrated (PPP holds) + Financial markets segmented
- Use your home currency risk-free rate
- Use the domestic market portfolio (financial markets are segmented)
- No FX risk — PPP holds
- This is just the single-country CAPM
\[E[\widetilde{r}] = r_f + \beta_M \times (E[{\widetilde{r}}_M] - r_f)\]
Back to the textbook domestic CAPM — but with a domestic benchmark
Case 4: Both Segmented (e.g., UK–India)
Product markets segmented (PPP fails) + Financial markets segmented
- Use your home currency risk-free rate
- Use the domestic market portfolio (capital markets segmented)
- FX risk matters — PPP deviations plus limited hedging options
- Run a multivariate regression for \(\beta_M\) and \(\beta_s\)
\[E[\widetilde{r}] = r_f + \beta_M(E[{\widetilde{r}}_M] - r_f) + \beta_s(E[\widetilde{s}] + r^{FC} - r_f)\]
If the company is perfectly hedged: \(\beta_s = 0\) \(\rightarrow\) reduces to Case 3
Worked Example: Data
Country A investor valuing a project in Country B. Financial markets are segmented.
| Risk-free rate, Country A |
\(r^A\) |
3% |
| Risk-free rate, Country B |
\(r^B\) |
5% |
| E[return on A market] |
\(E[{\widetilde{r}}_A]\) |
10% |
| E[return on world market] |
\(E[{\widetilde{r}}_W]\) |
8% |
| E[exchange rate return] |
\(E[\widetilde{s}]\) |
1% |
| Var(A market) |
\(\text{Var}[{\widetilde{r}}_A]\) |
0.0324 |
| Cov(project, A market) |
\(\text{Cov}[{\widetilde{r}}_j, {\widetilde{r}}_A]\) |
0.0432 |
| Cov(project, FX) |
\(\text{Cov}[{\widetilde{r}}_j, \widetilde{s}]\) |
0.004 |
| Var(FX) |
\(\text{Var}[\widetilde{s}]\) |
0.02 |
Testing Product Market Integration
We estimate a PPP regression:
\[\ln\left(\frac{S_{t+1}}{S_t}\right) = -0.06 + 0.89 \times (I^A_{t,t+1} - I^B_{t,t+1})\]
- The slope coefficient (0.89) is not significantly different from 1
- The constant (\(-0.06\)) is not significantly different from 0
- \(\Rightarrow\) Cannot reject Relative PPP
Conclusion: Product markets are integrated
Financial markets segmented + Product markets integrated = Case 3
Worked Example: Solution
Case 3: Domestic CAPM (FM segmented, PM integrated)
\[E[r_j] = r^A + \beta_A \times (E[{\widetilde{r}}_A] - r^A)\]
Compute beta against the domestic (A) market:
\[\beta_A = \frac{\text{Cov}[{\widetilde{r}}_j, {\widetilde{r}}_A]}{\text{Var}[{\widetilde{r}}_A]} = \frac{0.0432}{0.0324} = 1.333\]
Expected return:
\[E[r_j] = 0.03 + 1.333 \times (0.10 - 0.03) = 0.03 + 0.0933 = \mathbf{12.33\%}\]
Note: we used the domestic market premium, not the world market premium, even though we’re valuing a foreign project!
The Practical Problem with Bilateral Betas
The 2×2 framework uses \(\beta_s\) for one bilateral exchange rate
But a multinational faces MANY currencies:
- A European firm with subsidiaries in the US, Japan, UK, Brazil…
- Cannot reliably estimate \(N\) separate bilateral betas
Solution: Factor models
- Identify common risk factors in currency markets
- Just as Fama-French replaced single-beta CAPM in equities
- A firm’s currency exposure can be decomposed into factor loadings
\(\Rightarrow\) From bilateral \(\beta_s\) to systematic factor exposures
From UIP Failure to Risk Factors
Recall from Lecture 5: UIP fails dramatically
- 75+ studies: average slope \(b = -0.88\) (should be \(+1\))
- \(\Rightarrow\) FX risk premia exist and are economically large
But how are they structured?
Key insight (Lustig, Roussanov, Verdelhan, RFS 2011):
- Sort currencies by interest rate into portfolios
- This sorting reveals systematic factor structure
- High interest rate currencies earn high returns \(\rightarrow\) carry factor
The cross-section of currency returns is not random — it has structure
The Carry Factor (HML)
Construction: Sort currencies into 6 portfolios by interest rate
- Long highest interest rate portfolio
- Short lowest interest rate portfolio
- The difference is the HML carry factor
Key statistics (LRV 2011):
| HML Carry |
3.31% |
9.56% |
0.35 |
- Positive returns most months — but severe crashes in crises
- “Picking up pennies in front of a steamroller”
Carry Trade: Cumulative Returns
Carry Trade: Crash Risk
The Dollar Factor (DOL)
Average return of all currencies against the USD
- Captures broad dollar strength/weakness
- Acts as the “level” factor (carry is the “slope”)
When global risk appetite falls:
- USD strengthens (flight to safety)
- DOL turns negative; carry also crashes (high-yield currencies fall)
\(\Rightarrow\) DOL and carry are correlated but distinct
- DOL: directional dollar bet
- Carry: cross-sectional bet (long high minus short low)
Momentum and Volatility Factors
Momentum:
- Past currency winners continue to outperform (3-12 month horizon)
- Similar to equity momentum, but in FX
- Sharpe ratio \(\approx\) 0.45 — higher than carry!
Volatility:
- When global FX volatility spikes, carry crashes
- A “volatility innovation” factor captures this
- Negative correlation with carry returns
- Sharpe ratio \(\approx\) 0.30
These factors capture different dimensions of currency risk
Factor Sharpe Ratio Comparison
The Modern Factor Model
Replace bilateral \(\beta_s\) with systematic factor exposures:
\[E[rx_i] = \beta_{DOL} \times \lambda_{DOL} + \beta_{HML} \times \lambda_{HML} + \beta_{MOM} \times \lambda_{MOM} + ...\]
where \(\lambda\) are factor risk premia and \(\beta\) are factor loadings
Advantages over bilateral \(\beta_s\):
- Handles multiple currencies simultaneously
- Factors are tradeable (can be hedged)
- More robust estimation (fewer parameters)
A firm’s currency exposure = its factor loadings:
- High carry loading \(\rightarrow\) exposed to crash risk \(\rightarrow\) higher cost of equity
- Can hedge specific factors selectively
Three Questions Revisited with Factors
Q1: UIP holds \(\rightarrow\) all factor risk premia = 0
- No compensation for currency risk \(\rightarrow\) factors don’t matter
- But UIP fails empirically, so this case is rejected
Q2: Carry trade profitable \(\rightarrow\) \(\lambda_{HML} > 0\)
- Firms exposed to high-carry currencies face higher cost of equity
- This is compensation for bearing crash risk
Q3: Firm hedges FX \(\rightarrow\) all currency factor loadings \(\rightarrow 0\)
- Factor exposures drop out
- Another reason hedging can reduce the cost of capital
This Gives Us the APV Discount Rate
Lecture 10 established the APV framework:
\[V^{APV} = \underset{\text{Step 1: Base case}}{\sum_t \frac{E[\text{FCF}_t]}{(1 + r_{project})^t}} + \text{PV(financing)} + \text{Country risk adj.}\]
Now we can fill in \(r_{project}\):
- Determine the integration case (2×2 framework)
- Estimate the appropriate betas (market + FX or factor loadings)
- Apply the correct ICAPM formula
The rest of APV (Steps 2–5) is unchanged from Lecture 10
EuroCorp Revisited
Recall from Lecture 10: EuroCorp (German) evaluating a US project
US–Germany: PM segmented (PPP fails), FM integrated = Case 2
\[E[r] = r_f^{EUR} + \beta_W(E[r_W] - r_f^{EUR}) + \beta_s(\text{FX premium})\]
If EuroCorp hedges its USD exposure:
- \(\beta_s = 0\) \(\rightarrow\) reduces to global CAPM
- This is how we justified the 10% unlevered cost of equity in Lecture 10
If EuroCorp does not hedge:
- USD/EUR exposure adds a risk premium (positive or negative depending on \(\beta_s\))
- Cost of equity differs from the hedged case
Summary
Domestic CAPM: one factor (market), homogeneous expectations
\(\rightarrow\) International CAPM: two factors (world market + FX), PPP deviations
\(\rightarrow\) Factor models: carry, dollar, momentum, volatility
| Domestic CAPM |
FM segmented, PM integrated |
\(\beta_M\), domestic premium |
| Global CAPM |
FM integrated, PM integrated |
\(\beta_W\), global premium |
| ICAPM (2-factor) |
FM integrated, PM segmented |
\(\beta_W\), \(\beta_s\) |
| Factor model |
Multi-currency exposure |
Factor loadings |
Next lecture: Country Risk — the other missing piece (APV Step 4)
Course Connections
- Lecture 3 (PPP): PPP failure is why we need the FX factor
- Lecture 5 (UIP): UIP failure means FX risk premia exist (carry trade evidence)
- Lectures 6–8 (Hedging): Hedging eliminates \(\beta_s\) — reduces cost of capital
- Lecture 9 (Financing): Basis affects cost of debt; this lecture addresses cost of equity
- Lecture 10 (Valuation): This fills in the discount rate for APV Step 1
Next: Country Risk completes the APV framework (Step 4)
- How should country risk enter valuation?
- Adjust cash flows or discount rates?
- The “500bp fallacy” revisited