Cost of Capitalintermediate

Risk-Free Rate, Equity and Country Risk Premiums

Three premiums anchor the cost of capital. The risk-free rate $k_{rf}$ is the base return on a safe asset, usually a Treasury yield matched to the cash-flow horizon. The equity risk premium $(k_m - k_{rf})$ is the extra return the whole market demands for bearing equity risk. The country risk premium is an add-on for valuations in emerging or politically exposed markets, where sovereign and geopolitical risk raise the return investors require. For a Vietnamese listed firm, a country premium is layered on top of a mature-market equity premium.

Try it yourself

Building the after-tax WACC

A firm's cost of capital is the market-value-weighted blend of what debt and equity holders require: WACC = w_d·k_d·(1 − T) + w_e·k_e. Equity is priced by the CAPM, k_e = r_f + β·ERP, while debt is taken after the interest tax shield, k_d·(1 − T). Only debt earns the shield, so it usually sits below equity in the blend.

Weighted average cost of capital7.50%

Cost of equity k_e 9.50%After-tax k_d 4.50%WACC 7.50%

Weight of debt w_d40%

Equity weight w_e = 60%

Pre-tax cost of debt k_d6.0%

Tax rate T25%

Cost of equity (CAPM)

Risk-free rate r_f4.0%

Equity beta β1.10x

Equity risk premium ERP5.0%

Equity costs 9.50% (=4.0% + 1.10x × 5.0%), debt costs 4.50% after the 25% shield. Blended at 40/60 they give a WACC of 7.50%.

Try this

Shift weight toward debt and WACC usually falls, because shielded debt is cheaper than equity. Raising the tax rate deepens the shield and lowers the after-tax cost of debt.

Note: only debt carries the (1 − T) tax shield, since interest is tax-deductible and dividends are not. The weights w_d and w_e should be market values of debt and equity, not book values, because WACC is the return the market requires today.

Reflect: if cheap shielded debt always lowers WACC, why not finance the firm almost entirely with debt? What does this model leave out about how k_d and k_e respond as leverage climbs?

Why it matters

Build the cost of capital from the ground up. Start with what a safe asset pays, add what the market charges for taking on equity risk, then for a riskier jurisdiction add what investors demand for sovereign and political exposure. A useful critical-thinking point is that even Treasuries are not truly risk-free once liquidity and inflation risk are admitted. The country premium is where macro and geopolitical risk enters valuation directly, and it is exactly the channel studied in the connected research below.

Formulas

Cost of equity with a country premium

k_e = k_{rf} + \beta_e\,(k_m - k_{rf}) + CRP

The country risk premium

CRP

is added for valuations in emerging or politically exposed markets. One common estimate scales a sovereign default spread by relative equity volatility, following Damodaran.

Equity risk premium

ERP = k_m - k_{rf}

The market’s excess return over the risk-free rate. It can be estimated from long-run historical averages or implied from current prices, and the two often disagree.

Worked examples

Scenario

An analyst values a Vietnamese listed firm. The risk-free rate is 3 percent, the firm’s beta is 1.0 and the mature-market equity risk premium is 5 percent. A country risk premium of 3.5 percent is added for sovereign and geopolitical exposure. Estimate the cost of equity.

Solution

Build it up in three layers. The base risk-free rate is 3 percent. The equity component is $\,1.0 \times 5\% = 5\%$ . The country premium adds 3.5 percent. The cost of equity is $\,3\% + 5\% + 3.5\% = 11.5\%$ . Without the country premium the estimate would be only 8 percent, which would understate the return investors require for an emerging-market position and overstate the firm’s value.

Common mistakes

✗The risk-free rate is genuinely riskless. Even Treasuries embed liquidity and inflation risk, so the label is an approximation rather than a fact.
✗One risk-free rate fits all cash flows. Match the maturity to the horizon. Short-horizon work may use a short Treasury, long-horizon valuations a ten-year rate.
✗The equity risk premium is a fixed, known constant. Historical and implied estimates differ, and the premium shifts with market conditions, so it is a judgement, not a given.
✗Country risk is just higher company risk and needs no separate term. Sovereign and geopolitical risk is a market-wide add-on, the country risk premium, layered on top of the equity premium.

Revision bullets

•Risk-free rate is the safe base return, matched to the cash-flow horizon
•Equity risk premium is the market’s excess return over the risk-free rate
•Country risk premium is added for emerging or politically exposed markets
•Even Treasuries are not truly risk-free once liquidity and inflation are admitted
•Historical and implied equity premium estimates often disagree
•A Vietnam valuation layers a country premium on a mature-market premium

Quick check

For an emerging-market firm with a beta of 1.0, a risk-free rate of 4 percent, an equity risk premium of 5 percent and a country risk premium of 3 percent, the cost of equity is

The equity risk premium is best defined as

Connected topics

Macro & Geo Risk WACC Cost of Equity (CAPM)Cost of Debt Debt Beta

Sources

Titman & Martin
Titman, S. & Martin, J. D. Valuation: The Art and Science of Corporate Investment Decisions. Pearson.
Chapter on the risk-free rate and the market equity risk premium as CAPM inputs.
Damodaran (2022)
Damodaran, A. "Equity Risk Premiums: Determinants, Estimation and Implications." NYU Stern Working Paper, 2022.
Standard reference for estimating the equity risk premium and the country risk premium for emerging markets.
Connected research: Nguyen et al. (2024, 2025)
Nguyen, V-P. et al. "The Role of Geopolitical Risks in Shaping National Reserves and Resource Management Strategies: A Global Perspective." Resources Policy, 2024; "Geopolitical Risks, Monetary Trilemma, and Global Stagflation." International Economics and Economic Policy, 2025.
Course author research on how geopolitical risk shapes the macro environment, the channel behind the country risk premium added for emerging-market valuations.

How to cite this page

Dr. Phil's Quant Lab. (2026). Risk-Free Rate, Equity and Country Risk Premiums. Derivatives Atlas. https://phucnguyenvan.com/concept/sabv-risk-premiums

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