CFA Program Level I
Credit risk, expected loss and credit spreads: CFA Level I
Expected credit loss is probability of default x exposure at default x loss given default, where loss given default is 1 minus the recovery rate. The credit spread is a corporate bond's yield minus a government bond yield of similar maturity. It covers more than expected default loss: liquidity, tax and risk premiums are part of it too.
The three inputs to expected loss
Probability of default (PD): the chance the borrower defaults within the period, usually one year.
Exposure at default (EAD): the amount outstanding if default happens.
Loss given default (LGD): the percentage of the exposure lost after recoveries from collateral and work-out. LGD = 1 - recovery rate.
Expected loss = PD x EAD x LGD. As a percentage of the exposure, it is PD x LGD. The Basel Committee notes that banks treat expected loss as a cost of doing business and cover it through pricing and provisions; capital is held for losses above it.
Worked example
A EUR10,000,000 loan has a one-year PD of 1.2%. The lender expects to recover 35% if the borrower defaults, so LGD = 65%.
Expected loss = 0.012 x 10,000,000 x 0.65 = EUR78,000, or 0.78% of the exposure.
A common mistake is to multiply by the recovery rate: 0.012 x 10,000,000 x 0.35 = EUR42,000, which is the expected recovery on default, not the expected loss.
What a credit spread pays for
The San Francisco Fed measures the credit spread as the yield on a corporate bond minus the yield on a government bond of comparable maturity. Spreads widen in recessions and narrow in expansions.
Default risk is only part of the spread. One estimate cited there puts expected default losses at under 20% of the spread. Other parts are state taxes on corporate interest and compensation for the bond market's illiquidity.
Measured default probabilities vary less over the cycle than spreads do. In bad times, investors demand more compensation for risk than fundamentals explain, so spreads widen more than default risk alone would imply.
Seniority, collateral and recovery
A secured bond is backed by specific pledged assets. On default, its holders have a legal right to foreclose on that collateral.
Unsecured bonds, or debentures, have a general claim on the issuer's assets and cash flows. Senior debentures rank ahead of junior (subordinated) debentures.
The Basel note says LGD depends, among other things, on the type and amount of collateral. A credit rating estimates relative default risk; it does not measure liquidity risk or say whether a price is good value.
Where the exam catches people
- Believing LGD is the recovery rate: LGD is 1 minus the recovery rate.
- Believing the whole credit spread is compensation for expected default losses: liquidity, tax and risk premiums make up much of it.
- Believing spreads widen in recessions only because default risk differences between rating classes grow: research finds default probabilities vary less than spreads do.
- Believing a senior unsecured debenture ranks ahead of a secured bond on the pledged collateral: the secured holders have the claim on that asset.
- Believing two bonds with the same rating have the same liquidity or value: a rating addresses default risk only.