set_seed(42)) and publicly anchoredOne individual customer, then seven cohort views (the annuity-analog discipline says quote the cohort, not the point). Cases 5–8 give the four customer-cohort lenses a reviewer can slice the book by — tenure, multi-product, producer book, and geography. Each case answers one question in plain language and covers one part of the paper.
| # | Case study | Grain | The one-line takeaway | Paper |
|---|---|---|---|---|
| 1 | Maria Chen — one customer, six models | individual | Six unrelated models value the same customer within ±9%. | §4, §6 |
| 2 | CLV segments → loss-ratio gradient | cohort | CLV rank tracks loss cost (1.73 → 0.17) — so it's filing-relevant. | §7.1 |
| 3 | Cross-sell — filing vs planning | cohort | Growth value is a separate, auditable $693/customer — never in a rate. | §2.1, §8 |
| 4 | New business is written at a loss | cohort | Year-1 margin is a fraction of year-2; acquisition is recouped over renewals. | §4.3, §7.4 |
| 5 | Seasoning — loss ratio by tenure | cohort | Early years run worse; the lifetime view weights them by certainty. | §7.2 |
| 6 | Multi-product cohorts | cohort | Each added product cuts the lapse hazard — cross-sell buys persistence. | §6, retention |
| 7 | Producer-book cohorts | cohort | Books vary ~2× in value; 20% of it sits with lapse-adjacent customers. | §7 agency mgmt |
| 8 | Geography cohorts | cohort | Regional CLV tracks loss ratio — and passes the four-fifths fairness screen. | §8 regulatory |
If six different models disagree, why trust any of them?
Maria is the proposal's illustrative customer, cast into the book: a 2-product household (auto + home), tenure 5, coverage tier 2, a clean low-risk file (claims ≈ $0), combined premium ≈ $3,428. Her 5-year filing CLV under all six families:
Reproduce: python docs/calls/case_studies_data.py (Case 1).
Is a CLV segmentation actually about loss cost — or just willingness to pay?
Rank the book into five equal segments by filing CLV and read each segment's loss ratio. The gradient is monotone at the extremes — the bottom quintile destroys value at a 1.73 loss ratio (mean CLV −$10,496), the top runs at 0.17 (mean CLV +$14,850):
The credibility-weighted relativity runs 3.01 (Q1) down to 0.34 (Q5) — and it is indicated by the loss-ratio column alone, so it would hold under any labeling. That is the filing-defensible use of CLV.
Reproduce: case_studies_data.py (Case 2) → clv_rate_relativities; paper §7.1.
Where does the value of a cross-sell program go — and does it touch a rate?
Every CLV comes in two versions from the identical calculation. The filing variant is the renewal book as it stands (P − L − E). The planning variant adds the value of growth you hope for (cross-sell + upsell). The gap between them is an exact, auditable dollar figure:
Reproduce: case_studies_data.py (Case 3); paper §2.1, §8.
Why does splitting acquisition vs renewal expense change the story?
Acquiring a customer costs far more than renewing one (40% of first-year premium vs 20% after). For one new customer (avg premium $4,013, loss $2,249, retention 0.934), the cumulative discounted margin climbs over the relationship:
On this book, at the default 0.40 acquisition ratio the customer breaks even within year 1; the classic "written at a loss" pattern deepens as acquisition cost rises (breakeven moves to year 2 near 0.55). Charging a renewal the sunk acquisition cost would understate the in-force book by ~$573/customer (§4.3).
Reproduce: case_studies_data.py (Case 4) → expense_recovery_exhibit.
Does a customer's loss experience change as the relationship ages?
Loss ratio by tenure year shows clear seasoning: new business runs hot (0.63 at tenure 0), settling into the low 0.40s by tenure 8+. Weighting each year's loss ratio by the certainty of reaching it gives the survival-weighted lifetime loss ratio of 0.536, above the pooled 0.525 — because the early, worse years are the ones you are sure to experience:
Reproduce: case_studies_data.py (Case 5) → retention_adjusted_loss_ratio.
Does cross-selling actually make customers stay — or just add premium?
The fitted product-state Markov model gives the annual lapse hazard for each product-count state directly. It falls sharply as the household holds more products:
Reproduce: case_studies_data.py (Case 6) → MarkovCLV.transition_.
Which producer's book is worth the most — and how much of it is about to walk?
Group every customer under their producer (12 books here). Each book's value is the sum of its customers' CLV; the at-risk slice is the value tied up in in-force customers whose renewal outlook is in the bottom quartile — the ones a retention call should reach first.
Reproduce: case_studies_data.py (Case 7). Producer assignment is a
deterministic synthetic split (customer_id % 12); paper §7 / notebook 05.
Does CLV differ by region — and is that difference fair?
Mean CLV by region tracks the region's loss experience: FL and CA (loss ratios ~0.51–0.53) sit highest, NY and GA (~0.60) lowest. So the CLV difference is a loss-cost difference, not a geographic preference:
Reproduce: case_studies_data.py (Case 8) → disparate_impact_test; paper §8.
Every toolkit figure on this page is printed by
python docs/calls/case_studies_data.py on the seeded synthetic book
(set_seed(42), 5,000 households, 2015–2025). Public anchors (premiums, loss ratios,
expense, retention, discount) are each cited to a loaded primary source in
research/data/calibration_benchmarks.md. Synthetic data only — no proprietary data.
Full detail: worked examples · the paper (§4–§8).