Phase 1 — Framework & Reference Foundations

Customer Lifetime Value Pricing · CAS Ratemaking Working Group
Phase 1 — Done
CAS window Jun 11–24 · Framework updated Jul 2 (§ two-variant CLV)
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Literature corpus
16 papers
Research streams
4 → 1 toolkit
Framework
CLV definition + taxonomy ✓
First model
BG/NBD built & tested

The CLV framework for P&C ratemaking

Proposed working definition — for POG endorsement

Customer Lifetime Value is the expected present value of a P&C customer's future underwriting cash flows — premium net of losses and expenses — across the multi-year renewal relationship, weighted at each renewal by the probability the customer is still with us.

Three commitments this definition bakes in — i.e. how the work is framed:

  • An actuarial annuity, not a marketing score. Retention plays the role of survival; cash flows are analyzed in cohorts with uncertainty bands, not false-precision per-customer dollars.
  • A bright line between filing-eligible and business-only. The premium/loss/retention core must correlate with expected loss (defensible in a rate filing); cross-sell / referral (the X term) is business-optimization, carved out of rate indications in strict jurisdictions (NY §2304). Regulatory defensibility is a design constraint from day one.
  • Renewal = a purchase occasion, so one definition spans every model family (probabilistic, survival, multi-state, ML/hybrid) under a single predict_clv() contract — the probabilistic form drives the filing exhibits.

Asking POG to confirm three conventions that change the exhibits: (a) residual vs total CLV horizon · (b) discount-rate basis (prescribed / risk-free + margin / sensitivity-only) · (c) cross-sell excluded from rate indications across all target states or only the strict ones.

CLV supplements single-term loss projection with a multi-horizon view of the customer relationship. For customer i over horizon T years, discounted at rate d:

CLVi = Σt=1..T  Si(t) · [ Pi(t) − Li(t) − Ei(t) + Xi(t) ] / (1 + d)t
TermMeaningWhere it comes from
S(t)Survival / retention probability to term t — the renewal analog of survival in lifeBrockett 2008 · Dong–Frees 2022
P(t)Expected premium (grows with tenure / coverage) Gupta 2004 (margin core)
L(t)Expected losses in term t actuarial loss linkage
E(t)Expenses (acquisition, servicing) Gupta 2004
X(t)Cross-sell / referral value business-optimization only Verhoef–Donkers 2001

Two framing decisions sit on top of the equation

Cohort, not point estimate CLV is structurally an actuarial annuity with retention as survival — so we report segment/cohort CLV with uncertainty bands, not false-precision per-customer dollars. (Orliński 2026 annuity analog.)
Actuarial vs business-optimization split Filing-eligible: retention-adjusted loss ratios, tenure-correlated loss differences (must correlate with expected loss). Operational only: cross-sell / referral value (the X term) — excluded from rate indications in strict jurisdictions (NY §2304).

Framework update (Jul 2) — every model reports CLV in two variants

Refinement for POG review — Call #2, Jul 2

The single CLV equation is reported as two side-by-side columns: an base variant valuing the renewal book as-is (P − L − E, with X = 0), and a with-growth variant that additionally counts explicit cross-sell + upsell value (the X term made concrete).

  • Base clv_base — the filing-defensible base; coincides with the "actuarially justified" side of the bright line; the rate-side number in strict jurisdictions (NY §2304).
  • Constrained clv_with_growth — the business-planning view under explicit cross-sell (products added to the household — Verhoef–Donkers 2001 potential value) and upsell (coverage-tier / limit upgrades — the Markov transition dynamics) assumptions; for marketing, distribution and agency management.
  • The gap between the two columns is exactly the discounted value attributed to business-development assumptions — an auditable decomposition for regulators and management.
  • Toolkit contract: every predict_clv() returns both columns; sensitivity_analysis() sweeps cross-sell and upsell as explicit grid dimensions.

Labels settled on POG review, 16 Aug 2026. These columns were clv_unconstrained / clv_constrained through paper v2.0. AJ Robinson's review established that actuaries read "constrained" as regulatorily constrained — the filing-safe variant — which is the opposite of the sense intended. Since the word is ambiguous in the direction it points, flipping it would have preserved the ambiguity; the pair was renamed to the neutral base / with growth. The old column names remain as deprecated aliases for one release, so nothing that already runs breaks. The decomposition itself is unchanged.

Model taxonomy — one predict_clv() contract across families

FamilyCapturesToolkit classStatus
Contractual probabilisticRenewal-cycle retention (each renewal = purchase occasion) BGNBD_CLV, ParetoNBD_CLV BG/NBD ✓
SurvivalTime-to-lapse hazardCox PH / AFT next
Multi-product transitionCoverage-tier / product-addition dynamics MarkovCLV, HMMPhase 3
Predictive ML3yr/5yr value from rich features EnsembleCLV (XGBoost/LightGBM)Phase 3
Hybrid (headline)BG/NBD base + ML residual correction; probabilistic form for filings EnsembleCLV (hybrid mode)POG-selected

How the framework came from the references

16-paper corpus organized into four research streams. For each reference: what we took into the framework — not just that it was read.

Customer-base valuation Insurance survival Multi-state churn Probabilistic BTYD + ML Practitioner / regulatory
ReferenceWhat we took into the frameworkFeeds
Gupta, Lehmann & Stuart (2004)
valuation
The discounted retention–margin core of CLVi (we generalize their scalar margin to time-varying P−L−E+X); cohort-reporting discipline; retention as the dominant value lever → why we run retention sensitivities first. CLV_i skeleton
Verhoef & Donkers (2001)
valuation
Current-vs-potential value framing for segmentation; justification for the X (cross-sell) term as forecastable. Caveat carried forward: business-optimization, stays out of strict-state rate indications. cross_sell_adjusted_premium()
Brockett et al. (2008)
survival
Household/portfolio grain for retention (not policy-level); the logistic + survival (hazard) specification for the S(t) term; "first-cancellation → total-defection window" → treat partial lapse as an early-warning state. Cox PH / AFT survival
Guillén, Pérez-Marín & Guelman (2013)
survival
The explicit retention ↔ price-elasticity ↔ profit linkage; heterogeneous-treatment framing for the proposal's "retention credit". Caveat: grey-lit presentation — cite peer-reviewed companions. clv_rate_relativities(),
retention_adjusted_loss_ratio()
Dong, Frees, Huang & Hui (2022)
multi-state
Direct template for MarkovCLV (coverage-tier transitions) + HMM latent-state extension; 2nd-order-Markov MLR as a benchmark row. The paper's own claim — multi-state retention yields more accurate CLV. Closest actuarial anchor. MarkovCLV, HMM
Schmittlein, Morrison & Colombo (1987)
BTYD
Foundational "buy-till-you-die" precedent for ParetoNBD_CLV (native hyp2f1, next in queue) and conceptual parent of the BG/NBD base. ParetoNBD_CLV
Fader, Hardie & Lee (2005)
BTYD
Direct basis for BGNBD_CLV — built & tested. Closed-form log-likelihood + eq.10 expectation via hyp2f1 + discounted DERT; each renewal = a purchase occasion. The probabilistic base of the hybrid headline model. BGNBD_CLV ✓
Haddadi & Hamidi (2025)
ML
Closest published template for the headline architecture — named support for EnsembleCLV and the hybrid (BG/NBD base + ML residual). Our answer to "is the hybrid grounded in the literature?" EnsembleCLV (hybrid)
Wong, Viloria Garcia & Lim (2025)
ML
Empirical precedent for probability + ML in a non-contractual setting; supports framing insurance renewals as purchase occasions. hybrid validation
Mahdiyasa, Pasaribu & Sari (2025)
multi-state
Validated insurance precedent for MarkovCLV (active/upgraded/lapsed + survival). (= the proposal's mis-cited "Widyawan et al. 2025".) MarkovCLV
Jena et al.
ML
A plain-regression CLV baseline for the model-comparison table — the contrast that shows what a deployable regressor gives up vs. probabilistic + hybrid models. comparison baseline
Orliński (2026)
practitioner
The annuity analog and skeptical discipline — CLV as a relative signal, reported at cohort grain with uncertainty bands, not false-precision dollars. cohort-reporting design
CAS (2004 & 2014)
CAS precedent
CAS's own precedent that CLV belongs in P&C pricing over a multi-renewal horizon under regulatory constraint — establishing that the gap we fill is an implementation-ready, reproducible toolkit, not the concept. (Exact works to confirm with POG.) positioning / gap
Parr Rud (2001)
practitioner
Practitioner LTV-scoring lineage (SUGI/SAS) — a "before" contrast point showing how far the field predates a regulator-ready, reproducible framework. related work / contrast
Balona (2025)
governance
Grounds the AI-usage disclosure discipline (docs/ai_usage_log.md, a contract requirement) and responsible-AI framing in the methodology section. AI disclosure / methods

The synthesis: marketing CLV gives the valuation skeleton; insurance survival/multi-state gives insurance-grade retention dynamics; BTYD gives the probabilistic engine; the 2025 hybrid papers give the named template. None ships a regulator-ready, reproducible ratemaking toolkit — that is our contribution.

Assumptions to validate & open questions for POG

VALIDATE assumptions baked into the framework that we'd like POG to confirm  ·  DECIDE genuine design choices where POG steer now saves rework before Phase 3/4 deepen.

VALIDATERenewal = purchase occasion
We bridge non-contractual BTYD to the quasi-contractual annual renewal by treating each renewal as a purchase occasion. Confirm this framing is sound for P&C.
VALIDATEDiscount rate = 8%
Proposal uses 8%. Anchor on a prescribed/regulatory rate, risk-free + risk margin, or present discount rate only as a sensitivity (no single headline rate)?
VALIDATEExpense ratio = 0.25; loss basis
Single 0.25 expense ratio vs. split acquisition/renewal + ULAE/commission? Losses on an ultimate (developed) vs incurred basis — should synthetic data carry loss development?
VALIDATECross-sell excluded from filings
The X term is business-optimization only. Confirm exclusion from rate indications across all target states (CA/TX/NY/CO), or only strict NY with others allowed?
DECIDECLV horizon basis
Report residual CLV (future renewals only — current default) or total CLV including the current term? Different conventions for filing exhibits.
DECIDEReporting grain
Filing exhibits at segment/cohort grain with uncertainty bands (our lean), or per-customer point estimates as well?
DECIDEHybrid: interpretability vs accuracy
For the probabilistic filing form, how to weight explainability/defensibility vs raw accuracy in the ML-residual layer? (monotonic constraints, SHAP exhibits, capped residual influence)
DECIDELines: per-line vs pooled BOP
Both, personal-led is confirmed. For commercial BOP (different retention dynamics) — separate models per line or a pooled model with line covariates?
DECIDERegulatory proxy rigor
For CA Prop 103 & CO SB21-169 disparate-impact testing — which protected-class proxy set and what thresholds? Scopes Phase 4.
DECIDEWorked-example calibration
Should the toolkit reproduce the proposal's ~$4,890 5-yr CLV (Maria-Chen) as a validation target, or is that purely illustrative?

Two reference housekeeping items to surface

Dropped reference Proposal ref "Bolaños/Guillén/Nielsen 2012 (JRI)" couldn't be located/confirmed; substitute scan was image-only. Dropped — Guillén et al. (2013) covers the same Barcelona-group ground.
Citation corrections "Widyawan et al. (2025)" = Mahdiyasa et al. (2025); "Wardani et al. (2015)" = the ITB-Bandung 2015 AIP paper, superseded by Mahdiyasa 2025. Ask POG to confirm the exact CAS 2004/2014 works.
This research project has been funded by the Casualty Actuarial Society.