Risk Pooling
The practice of combining many individual risks into a group so that losses of the few are covered by contributions of the many.
What is Risk Pooling?
Risk pooling is the foundational mechanism of insurance, in which many individuals or entities contribute premiums into a shared pool from which claims are paid. By aggregating risks, the insurer leverages the law of large numbers: while any individual's loss is unpredictable, the aggregate loss across a large pool is statistically foreseeable and manageable. Effective risk pooling requires that the pool be large and diverse enough to prevent adverse selection (the tendency of higher-risk individuals to disproportionately seek coverage) from destabilizing the pool's finances. Governments mandate participation in certain pools — such as the ACA's health insurance markets and state workers' compensation systems — specifically to ensure broad, balanced risk sharing.
Example
A health insurer covers 100,000 members, each paying a $500 monthly premium ($600M annually). Actuaries project that 2% of members will incur catastrophic claims averaging $250,000, totaling $500M. The remaining $100M covers administrative costs and profit. No individual member can predict whether they will be among the 2%, but the pool absorbs each loss without financial hardship to the individual.
Source: National Association of Insurance Commissioners — Insurance Basics