Worked case · Failure and stress · 12 figures

Recorded reserve versus available cover

Understand reserve structures

Figure 01 / 12

Separate probability, severity, and exposure

Separate probability, severity, and exposure — Recorded reserve versus available cover. One-year synthetic credit case. Exact values are in the figure data below.
One-year synthetic credit case

The simplified one-year expected loss is PD × LGD × EAD = $38,111.29. PD is 10.35%, LGD is 71.50%, and EAD is $515,000. This is a teaching expected-value calculation, not an accounting allowance method or a capital standard.

Figure data and text version
InputValueUnit
PD10.35Percent over one year
LGD71.5Percent of exposure lost conditional on default
EAD515,000USD at default
Expected loss38,111.29USD over the stated horizon

The ledger shows a reserve balance, but its usefulness depends on access, currency, legal rights, and competing claims. A reassuring balance may be unavailable when needed.

The reserve sits with the same counterparty that is under stress.

All amounts, rates, capacity limits, and outcomes in this case are synthetic. The three conditions are separate assumptions for comparison. A better result in the response condition is not measured proof that the proposed control causes that improvement. The figures expose the calculation and its limits; a real deployment needs its own evidence.

Read the result

The case has $515,000 of exposure. Its stated one-year PD and LGD imply $38,111.29 of expected loss, while the cover analysis leaves $332,000.00 of stress exposure. Monthly cash coverage is 0.83×. These are separate measures: one describes an average under probability assumptions, one describes available cover, and one describes a period’s funding capacity.

Model inputs and calculated values

Inputs below are the case-specific values. Each figure states the condition-specific assumptions and units used in its calculation. Calculated values are rounded for display.

InputValue
exposure515,000
collateral160,000
reserve95,000
pd0.045
cash28,000
debtService21,000
Calculated valueResult
ead515,000
pd0.1035
lgd0.715
expectedLoss38,111.29
eligibleCover88,000
reserve95,000
uncovered332,000
cash17,360
debt21,000
dscr0.8267
Figure 02 / 12

Probability and severity move the result together

Probability and severity move the result together — Recorded reserve versus available cover. USD expected loss; fixed exposure. Exact values are in the figure data below.
USD expected loss; fixed exposure

Each cell is the same exposure multiplied by the row default probability and the column loss severity. The grid makes joint stress visible. A downturn can affect both factors; the calculation does not assume that the two causes are independent.

Figure data and text version
PDLGD 25%LGD 50%LGD 75%
2%2,5755,1507,725
5%6,437.512,87519,312.5
10%12,87525,75038,625
20%25,75051,50077,250
Figure 03 / 12

Recorded collateral and eligible cover

Recorded collateral and eligible cover — Recorded reserve versus available cover. USD; some measures overlap. Exact values are in the figure data below.
USD; some measures overlap

The collateral record is $160,000, but a 45% illustrative haircut leaves $88,000.00 eligible in this scenario. Reserve cover adds $95,000. The resulting uncovered exposure is $332,000.00. Eligibility also needs enforceability and operational access; this arithmetic does not establish either.

Figure data and text version
MeasureUSD
Recorded collateral160,000
Eligible collateral88,000
Recorded reserve95,000
Combined usable cover183,000
Uncovered exposure332,000
Figure 04 / 12

Cash available for the period’s debt service

Cash available for the period’s debt service — Recorded reserve versus available cover. USD for one month. Exact values are in the figure data below.
USD for one month

Defined cash available is $17,360.00 against $21,000.00 of debt service, for a 0.83× ratio. The ratio uses one period and one defined cash measure. It does not establish affordability, suitability, or a required underwriting threshold.

Figure data and text version
ComponentUSDMeaning
Cash available17,360After the expenses included in this illustration
Debt service21,000Principal and interest due in the same period
Cash after debt service-3,640Negative means a modeled shortfall
Figure 05 / 12

A constant-hazard illustration

A constant-hazard illustration — Recorded reserve versus available cover. Percent of an initial synthetic cohort. Exact values are in the figure data below.
Percent of an initial synthetic cohort

The curve converts the stated one-year PD of 10.35% to a constant monthly hazard using h = 1 − (1 − PD)^(1/12). Survival after 12 months is therefore 1 − PD. Constant hazard is an assumption; seasonality and changing exposure are omitted. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
Months since startSurvival %
M0100
M298.2
M496.42
M694.68
M892.98
M1091.3
M1289.65
Figure 06 / 12

Cumulative expected loss at comparable age

Cumulative expected loss at comparable age — Recorded reserve versus available cover. Cumulative expected USD; fixed exposure. Exact values are in the figure data below.
Cumulative expected USD; fixed exposure

This curve multiplies cumulative modeled default probability by a fixed EAD and LGD. It is useful for separating observation age from the chosen assumptions. It omits amortization, recoveries over time, prepayment, and changing utilization. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
AgeExpected USD
M00
M26,644.51
M413,169.13
M619,576
M825,867.27
M1032,045.02
M1238,111.29
Figure 07 / 12

Expected loss sensitivity to PD

Expected loss sensitivity to PD — Recorded reserve versus available cover. USD; LGD and EAD held fixed. Exact values are in the figure data below.
USD; LGD and EAD held fixed

Exposure stays at $515,000 and LGD stays at 71.50% while PD changes. The linear relationship follows the simplified expected-loss formula. It is not evidence that real-world losses respond linearly to economic stress. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
One-year PDExpected USD
1%3,682.25
3%11,046.75
5%18,411.25
8%29,458
12%44,187
20%73,645
Figure 08 / 12

A shared dependency can dominate exposure

A shared dependency can dominate exposure — Recorded reserve versus available cover. USD; buckets sum to total exposure. Exact values are in the figure data below.
USD; buckets sum to total exposure

The four amounts are disjoint portions of this case’s exposure. The largest bucket represents one shared supplier, funding source, or other specified dependency. Counting customers alone would not reveal this common loss driver.

Figure data and text version
Dependency bucketExposure USD
reserve-holding counterparty — primary206,000
Independent group B154,500
Independent group C103,000
Independent group D51,500
Figure 09 / 12

A weak month can disappear inside an average

A weak month can disappear inside an average — Recorded reserve versus available cover. USD per month. Exact values are in the figure data below.
USD per month

The six-month path applies explicit seasonal factors to the defined monthly cash amount and compares it with fixed debt service. These are constructed cash assumptions, not a forecast. A negative month needs a funding or terms response even when the average ratio looks comfortable. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
MonthCash availableDebt service
M112,15221,000
M214,75621,000
M319,09621,000
M415,62421,000
M522,56821,000
M619,96421,000
Figure 10 / 12

Terms belong in the decision record

Terms belong in the decision record — Recorded reserve versus available cover. Synthetic underwriting record. Exact values are in the figure data below.
Synthetic underwriting record

This record concerns understand reserve structures. A binary approval omits the amount, observation horizon, cover assumptions, and review trigger. Retaining those terms makes the decision reproducible and identifies when changed facts require another assessment.

Figure data and text version
FieldIllustrative value
entityRecorded reserve versus available cover
exposure_usd515,000
horizonOne year for PD; one month for cash coverage
pd_percent10.35
lgd_percent71.5
review_triggerThe reserve sits with the same counterparty that is under stress.
Figure 11 / 12

One cause can affect several loss components

One cause can affect several loss components — Recorded reserve versus available cover. Scenario logic. Exact values are in the figure data below.
Scenario logic

The stress path connects reserve-holding counterparty to repayment cash, default probability, recovery, and funding needs. Arrows state the scenario’s assumed causal chain. They are hypotheses to test with evidence, not proof that every affected customer will default.

Figure data and text version
StageMechanism
Dependency shockThe reserve sits with the same counterparty that is under stress.
Cash pressureReceipts fall or essential payments move earlier
Default and severityRepayment probability and recovery can both worsen
ResponseReassess terms, usable cover, and exposure within the approved process
Figure 12 / 12

Expected loss, uncovered exposure, and cash gap

Expected loss, uncovered exposure, and cash gap — Recorded reserve versus available cover. USD; distinct horizons and meanings. Exact values are in the figure data below.
USD; distinct horizons and meanings

Expected loss ($38,111.29), uncovered exposure ($332,000.00), and monthly cash gap ($3,640.00) answer different questions. The bars are deliberately separated measures and must not be added. A low expected value can coexist with a large stress exposure.

Figure data and text version
MeasureUSD
Expected one-year loss38,111.29
Uncovered stress exposure332,000
Monthly cash gap3,640

Connect the result to the system

State eligibility assumptions and report gross exposure, recorded reserve, usable cover, and residual exposure.

Check the population, evidence, permitted action, and actual effect together. A balanced calculation can still use the wrong population; a successful response can still leave an unknown financial outcome. The case’s numerical result applies only to its stated assumptions.

Sources and further reading

The chapter sources support the concepts and scope. They do not prescribe the synthetic model rates.

  1. OCC Comptroller’s Handbook: merchant processing
  2. OCC Comptroller’s Handbook: rating credit risk