Sharing risk can make the unmanageable manageable. A pooling arrangement is an agreement among insurers or other entities to combine premiums and losses for a defined portfolio of risks, each participant taking a predetermined share of the collective result.

Pools may be voluntary or mandated by law. They are used for residual markets, nuclear risks, terrorism, and other exposures that exceed individual appetite. A central administrator typically handles policy issuance, claims, and distribution of results. Governance rules address admission of new members, withdrawal, and deficit funding.

Pooling spreads volatility and can improve access to coverage. It also requires trust among participants and transparent accounting. When deficits arise, assessment mechanisms ensure that the pool can meet its obligations. The structure is a practical application of the law of large numbers across multiple balance sheets.

• Agreement to share premiums and losses among participants
• Used for large or residual risks
• Administered centrally under formal rules
• Spreads volatility across multiple insurers