FRM Exam Part I · Country Risk: Determinants, Measures, and Implications

Sovereign Default Risk and Credit Ratings for FRM Part I

Updated 11 October 2026 · Fact-checked

Sovereign default risk is the chance a government fails to pay its debt on time. Agencies such as Moody's and S&P assign letter ratings using political, economic and fiscal factors. Ratings map to default spreads, the extra yield over a risk-free rate. Ratings are lagging, coarse and can be biased, so spreads from markets often move first.

Understand Sovereign Default Risk and Credit Ratings

A sovereign default happens when a government fails to meet its debt obligations in full or on time. Unlike a company, a government cannot be easily forced into liquidation. It can tax, print its own currency, or negotiate with creditors. So sovereign risk depends on both ability to pay and willingness to pay.

Rating agencies turn this into a letter grade. They look at factors such as the size and growth of the economy, debt and deficit levels, external position (reserves, current account), political stability, institutional quality, and past default history. Ratings from Baa3 (Moody's) or BBB- (S&P) upward are investment grade. Anything below is speculative grade, or junk.

A key point is currency. Ratings are often issued separately for foreign-currency debt and local-currency debt. A government can print its own currency, so local-currency ratings are often higher than foreign-currency ratings. Default on foreign-currency debt is more likely, since the government cannot print dollars or euros.

The link to pricing is the default spread. This is the yield a government bond pays above a risk-free benchmark, such as a US Treasury for USD bonds. A worse rating usually means a wider spread. In the Damodaran approach, you take the average spread for each rating class and use it as the default spread for countries with that rating. You can then add it to the risk-free rate to get a cost of debt, or scale it up to estimate a country risk premium for equities.

Ratings have clear limitations. They are lagging, because agencies change them after the problems appear. They are coarse, because a country sits in a broad bucket even though risk differs inside it. They can be biased or inconsistent across agencies, and agencies are paid by the issuers they rate. They are also sticky, since agencies avoid frequent changes. Market-based measures such as sovereign bond yields and CDS spreads adjust daily and often react faster.

Key formulas to remember

Default spread: Default spread = Yield on sovereign bond − Risk-free rate; Both bonds must be in the same currency and have the same maturity. For example, a USD-denominated sovereign bond versus a US Treasury.
Cost of sovereign debt: Yield = Risk-free rate + Default spread; The default spread is the sovereign's compensation for default risk in that currency.
Rating-based default spread: Default spread for country = Average spread of bonds in the same rating class; Used when a country has no traded bond or CDS. It treats all countries with the same rating as equally risky.
Approximate expected loss link: Default spread ≈ Probability of default × Loss given default; A rough approximation for small values. It ignores risk premium, liquidity and other components, so actual spreads are usually wider.
Investment-grade boundary: Investment grade: Baa3/BBB- or higher; below is speculative grade; Moody's uses Baa3 and S&P and Fitch use BBB- as the lowest investment-grade rating.

How to solve Sovereign Default Risk and Credit Ratings questions

Use this method for any question on sovereign ratings, spreads or their limits.

1Identify what is asked: how a rating is set, a limitation, or a calculation involving a spread.
2If it is about determinants, sort the factors into economic, fiscal, external, political and institutional groups, and remember ability versus willingness to pay.
3Check the currency of the debt. Foreign-currency and local-currency ratings can differ, and this often explains the answer.
4For a spread calculation, subtract the risk-free yield from the sovereign yield, keeping currency and maturity the same.
5For a cost of debt, add the default spread to the risk-free rate. Convert percentages carefully, since 150 basis points is 1.50%.
6For limitations, link each one to a cause: lagging, coarse buckets, bias, stickiness, or agency conflicts.
7Compare with market measures, such as bond spreads or CDS, when the question asks which is more timely.
8Check that the final answer has the right sign and units, and that the spread is positive.

Quickest way: Spread and rating shortcut

When to use it: Use this when a multiple-choice question gives yields or a rating and asks for a spread, a cost of debt or the best-fitting statement.

Convert everything to the same units first: percent or basis points.
Spread = sovereign yield − risk-free yield. Add it back if you need a cost of debt.
If options are statements, eliminate any claim that ratings are timely, perfectly accurate or identical across agencies.
Remember that a lower rating means a wider spread, and local-currency ratings are usually equal or higher than foreign-currency ratings.
Pick the option that matches this logic.

Common mistakes in Sovereign Default Risk and Credit Ratings

Treating a rating as a precise default probability.
Letter grades look like exact measures.
Fix: Remember that a rating is an ordinal rank within a broad bucket. Default probabilities come from historical default studies, and they vary over time.
Mixing currencies when computing the default spread.
The sovereign yield and the benchmark are taken from different markets.
Fix: Always compare a USD sovereign bond with a US Treasury, and a EUR bond with a EUR risk-free benchmark.
Confusing basis points with percentages.
Spreads are quoted in basis points but yields in percent.
Fix: Divide basis points by 100 to get percent. 250 bp = 2.50%.
Saying ratings lead markets.
Ratings seem authoritative, so students assume they are early signals.
Fix: State that ratings tend to lag market spreads and CDS prices, and agencies change them slowly.
Assuming local-currency and foreign-currency ratings must be equal.
Students think one country has one rating.
Fix: A government can print its own currency, so local-currency risk is often lower. Check which currency the question refers to.
Treating the spread as pure expected loss.
The formula PD × LGD is memorised without its limits.
Fix: Use it only as an approximation. Actual spreads also include risk premium and liquidity compensation.

Worked examples

Example 1

A government has a 10-year USD bond yielding 6.80%. The 10-year US Treasury yields 4.30%. The country is rated Ba2. Calculate the default spread in basis points, and say what it implies for a USD loan priced off this bond if the risk-free rate rises to 4.80% and the spread stays the same.

Show the solution

Default spread = sovereign yield − risk-free rate.
Spread = 6.80% − 4.30% = 2.50%.
Convert to basis points: 2.50% × 100 = 250 bp.
New cost of debt = 4.80% + 2.50% = 7.30%.

Answer: The default spread is 250 bp. If the spread stays fixed and the risk-free rate rises to 4.80%, the cost of debt becomes 7.30%.

Example 2

Which statement about sovereign credit ratings is most accurate? A) Ratings react to deterioration faster than bond spreads. B) Ratings from all agencies are always identical. C) Ratings tend to lag market-based measures and group countries into broad buckets. D) Ratings measure only willingness to pay.

Show the solution

Test A: ratings are adjusted slowly, while spreads move daily. A is false.
Test B: agencies use different methods and often give different ratings. B is false.
Test C: ratings are lagging and coarse, which are standard limitations. C is true.
Test D: ratings consider both ability and willingness to pay. D is false.

Answer: C

Exam tips

Expect conceptual questions on limitations. Learn the list: lagging, coarse, sticky, biased, inconsistent across agencies.
Know the investment-grade line: Baa3 or BBB- and above.
Always check the currency of the debt before comparing ratings or spreads.
Practice converting between basis points and percent quickly, since spread questions are short calculations.
Know why spreads from bonds or CDS can be more timely than ratings, and why they can still be noisy due to liquidity.

Practice questions from Country Risk: Determinants, Measures, and Implications

Sovereign Default Risk and Credit Ratings in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Sovereign Default Risk and Credit Ratings: frequently asked questions

How are sovereign credit ratings determined?

Agencies assess economic strength, fiscal position, external balance, political and institutional quality, and debt history. They combine these into an assessment of ability and willingness to pay, then assign a letter grade. Each agency uses its own methodology and judgement.

What is the link between a sovereign rating and the default spread?

Lower ratings are associated with wider default spreads. In the Damodaran approach, the average spread of bonds in each rating class is used as the default spread for countries with that rating. This is useful when a country has no traded bonds or CDS.

What are the main limitations of sovereign ratings for FRM Part I?

Ratings lag the market, group different risks into broad buckets, and change slowly. Agencies can also differ in views and may face conflicts of interest. Market spreads and CDS tend to react faster.

Why can local-currency ratings be higher than foreign-currency ratings?

A government can print its own currency to repay local-currency debt, which lowers default risk on that debt. It cannot print foreign currency, so foreign-currency debt is riskier. The two ratings can therefore differ.