A deductible (or excess) is the portion of a loss retained by the insured before the policy responds, directly influencing both risk-sharing behavior and premium levels. Higher deductibles generally reduce premium but increase the insured’s volatility, making the choice a key tool in tailoring programmes to risk appetite and cash‑flow tolerance. For insurers, deductible structures affect claims frequency, administrative burden, and the shape of portfolio loss distributions, informing pricing, wording, and reinsurance strategy.
