Survival Analysis for Marketing

Time-to-event modeling with proper censored data handling. Three-tier approach: Kaplan–Meier (nonparametric) → Cox PH (semiparametric) → Time-to-Event prediction.

Core Equations (Katsov §2.6.2)

Survival Function (eq. 2.107–2.109)

S(t) = Pr(T > t) = 1 − F(t)           # probability of surviving past t

# Kaplan-Meier estimator (eq. 2.109):
Ŝ(t) = ∏_{i ≤ t}  (1 − d_i / n_i)    # product over observed event times