Worked case · Reference condition · 12 figures

Synthetic profile lifecycle

Synthetic identity is a lifecycle problem

Figure 01 / 12

The evaluated population

The evaluated population — Synthetic profile lifecycle. Count; one closed observation cohort. Exact values are in the figure data below.
Count; one closed observation cohort

The cohort contains 16,000 account lifecycles, of which 288 have the defined synthetic outcome: Synthetic fabricated-profile outcome. The outcome is known by construction here. In production, label uncertainty and selection must be recorded separately.

Figure data and text version
OutcomeCount
Synthetic fabricated-profile outcome288
Other labeled outcomes15,712

A fabricated profile can accumulate credible-looking history before a high-value action. The relevant unit is the account lifecycle, not one isolated application screen.

The reference case starts with the stated population and a functioning evidence path. The owner is risk operations.

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 rule flags 466 of 16,000 account lifecycles. Of those flags, 230 meet the synthetic target, giving 49.36% precision. It misses 58 target events. Under the stated cost assumptions, residual loss and operating friction total $42,142. The important result is the connection between the population, action, capacity, and outcome—not one isolated score.

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
population16,000
prevalence0.018
severity650
reviewCost7
Calculated valueResult
population16,000
positive288
negative15,712
tp230
fp236
fn58
tn15,476
loss37,700
severity650
precision49.36
recall79.86
Figure 02 / 12

Four outcomes of the rule

Four outcomes of the rule — Synthetic profile lifecycle. Counts; rows are actual labels, columns are actions. Exact values are in the figure data below.
Counts; rows are actual labels, columns are actions

The rule flags 230 synthetic positives and 236 negatives. It misses 58 positives. A flagged item is a decision to intervene; it is not proof of fraud, a legal prohibition, or any other real-world conclusion.

Figure data and text version
Known outcomeFlaggedNot flagged
Synthetic fabricated-profile outcome23058
Other outcome23615,476
Figure 03 / 12

Three rates with different denominators

Three rates with different denominators — Synthetic profile lifecycle. Rates within this cohort. Exact values are in the figure data below.
Rates within this cohort

Precision is 49.36%, recall is 79.86%, and the false-positive rate is 1.5%. Changing the denominator changes the meaning. This record keeps each numerator attached to the population from which it came.

Figure data and text version
MetricNumeratorDenominatorResult
Precision23046649.36%
Recall23028879.86%
False-positive rate23615,7121.5%
Figure 04 / 12

Precision changes with prevalence

Precision changes with prevalence — Synthetic profile lifecycle. Percent; fixed conditional detection rates. Exact values are in the figure data below.
Percent; fixed conditional detection rates

This sensitivity plot holds recall at 80% and false-positive rate at 1.5%, then changes prevalence. It is an algebraic comparison, not a forecast. Even unchanged detection quality can produce a very different review queue when the base rate changes. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
Assumed prevalencePrecision %
0.1%5.07
0.5%21.14
1%35.01
2%52.12
5%73.73
10%85.56
Figure 05 / 12

The threshold trade-off

The threshold trade-off — Synthetic profile lifecycle. Count in the same cohort. Exact values are in the figure data below.
Count in the same cohort

Six illustrative score bands use a stated pair of detection rates. Lower sensitivity can reduce false alarms but miss more target events. These points do not come from a trained model and do not establish the best operating threshold. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
Score bandTrue positivesFalse positives
Band 12822,357
Band 22711,257
Band 3248550
Band 4207189
Band 514463
Band 67216
Figure 06 / 12

A transparent loss-and-friction calculation

A transparent loss-and-friction calculation — Synthetic profile lifecycle. Illustrative USD; expected cost under stated intervention assumptions. Exact values are in the figure data below.
Illustrative USD; expected cost under stated intervention assumptions

At $650 severity per missed synthetic positive, residual loss is $37,700. Review costs $3,262; lost contribution on false alarms is $1,180. The calculation assumes intervention prevents all flagged-positive loss and each false alarm loses the stated contribution. Relax those assumptions before applying it to a real policy.

Figure data and text version
Cost componentUSD
Missed-positive loss37,700
Review cost3,262
False-alarm contribution1,180
Figure 07 / 12

Observed outcomes mature over time

Observed outcomes mature over time — Synthetic profile lifecycle. Count; final outcome fixed. Exact values are in the figure data below.
Count; final outcome fixed

The final synthetic positive count is 288. Earlier observations reveal only a stated fraction. Comparing a day-1 cohort with a day-30 cohort would confuse label age with control quality. This curve models observation delay only; it does not change the final outcome. Horizontal positions are the labeled observations or scenarios; equal spacing does not imply equal numerical increments.

Figure data and text version
Days after eventObserved positives
152
3101
7173
14236
30288
Figure 08 / 12

Review demand and available capacity

Review demand and available capacity — Synthetic profile lifecycle. Items in the cohort window. Exact values are in the figure data below.
Items in the cohort window

The flag count is 466. The comparison capacity is an illustrative 640 reviews per cohort window. A mathematical rule can be coherent while its resulting workload exceeds the operating team’s capacity. Capacity is not permission to ignore an applicable mandatory control.

Figure data and text version
Queue measureItems
Flagged for review466
Available capacity640
Excess demand0
Figure 09 / 12

A feature is an observation with provenance

A feature is an observation with provenance — Synthetic profile lifecycle. Illustrative data contract. Exact values are in the figure data below.
Illustrative data contract

This evidence contract supports synthetic identity is a lifecycle problem. A value needs its event time, arrival time, scope, and source. Keeping unavailable evidence distinct from a measured zero prevents an outage from becoming a falsely reassuring feature.

Figure data and text version
FieldExampleMeaning
entity_refSynthetic profile lifecycleSubject of this case
event_time2026-09-18T09:00:00ZWhen the event occurred
received_time2026-09-18T09:00:02ZWhen the system learned it
signal_statusavailableEvidence quality, not an outcome
label_definitionSynthetic fabricated-profile outcomeThe target used in these calculations
Figure 10 / 12

Missing evidence changes the observed population

Missing evidence changes the observed population — Synthetic profile lifecycle. Count; each row is the same cohort. Exact values are in the figure data below.
Count; each row is the same cohort

The cells show an explicitly constructed completeness profile for three signal groups. The stress condition removes more history and device evidence. Missingness does not prove the target outcome; it changes what the decision process knows.

Figure data and text version
Signal groupAvailableMissing
Identity evidence15,840160
Activity history15,680320
Context signal15,200800
Figure 11 / 12

Evidence, score, and action remain separate

Evidence, score, and action remain separate — Synthetic profile lifecycle. Decision lifecycle. Exact values are in the figure data below.
Decision lifecycle

The policy can use synthetic identity is a lifecycle problem only within its approved scope. The action record must retain which evidence was available, which model or rule ran, and which action was actually applied. The final action can differ from the score recommendation when a separate constraint applies.

Figure data and text version
StageRecord
ObserveSynthetic profile lifecycle: evidence as of the decision time
EvaluateRule flags 466 of 16,000 account lifecycles
ApplyRecord action, reason, owner, and expiry
ReconcileJoin the action to later outcomes without overwriting history
Figure 12 / 12

What the result cannot establish

What the result cannot establish — Synthetic profile lifecycle. Interpretation boundary. Exact values are in the figure data below.
Interpretation boundary

Observed classifications do not reveal every counterfactual. The synthetic labels make arithmetic possible, but production decline data is selected by prior policy. Keep measured outcomes, assumed prevention, and unknown alternatives separate when reporting impact.

Figure data and text version
ClaimEvidence in this caseLimit
Detected target230 known synthetic positives flaggedProduction labels may be delayed or wrong
Prevented lossAssumed 149,500 USDRequires an intervention-effect assumption
Customer impact236 synthetic negatives flaggedNot every flag causes abandonment
Unobserved alternativeOutcome without the actionNeeds a valid evaluation design

Connect the result to the system

Retain provenance and evaluate later authority changes against the full event history.

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. NIST SP 800-63A-4: identity proofing
  2. NIST SP 800-63B-4: authentication