Large number of similar exposure units: Since insurance operates through pooling resources, the majority of insurance policies are provided for individual members of large classes, allowing insurers to benefit from the law of large numbers in which predicted losses are similar to the actual losses. Exceptions include Lloyd's of London, which is famous for ensuring the life or health of actors, sports figures, and other famous individuals. However, all exposures will have particular differences, which may lead to different premium rates.
Insurance can influence the probability of losses through moral hazard, insurance fraud, and preventive steps by the insurance company. Insurance scholars have typically used moral hazard to refer to the increased loss due to unintentional carelessness and insurance fraud to refer to increased risk due to intentional carelessness or indifference. Insurers attempt to address carelessness through inspections, policy provisions requiring certain types of maintenance, and possible discounts for loss mitigation efforts. While in theory insurers could encourage investment in loss reduction, some commentators have argued that in practice insurers had historically not aggressively pursued loss control measures—particularly to prevent disaster losses such as hurricanes—because of concerns over rate reductions and legal battles. However, since about 1996 insurers have begun to take a more active role in loss mitigation, such as through building codes.
Protected self-insurance is an alternative risk financing mechanism in which an organization retains the mathematically calculated cost of risk within the organization and transfers the catastrophic risk with specific and aggregate limits to an insurer so the maximum total cost of the program is known. A properly designed and underwritten Protected Self-Insurance Program reduces and stabilizes the cost of insurance and provides valuable risk management information.