Definite loss: The loss takes place at a known time, in a known place, and from a known cause. The classic example is death of an insured person on a life insurance policy. Fire, automobile accidents, and worker injuries may all easily meet this criterion. Other types of losses may only be definite in theory. Occupational disease, for instance, may involve prolonged exposure to injurious conditions where no specific time, place, or cause is identifiable. Ideally, the time, place, and cause of a loss should be clear enough that a reasonable person, with sufficient information, could objectively verify all three elements.
In the United States, the most prevalent form of self-insurance is governmental risk management pools. They are self-funded cooperatives, operating as carriers of coverage for the majority of governmental entities today, such as county governments, municipalities, and school districts. Rather than these entities independently self-insure and risk bankruptcy from a large judgment or catastrophic loss, such governmental entities form a risk pool. Such pools begin their operations by capitalization through member deposits or bond issuance. Coverage (such as general liability, auto liability, professional liability, workers compensation, and property) is offered by the pool to its members, similar to coverage offered by insurance companies. However, self-insured pools offer members lower rates (due to not needing insurance brokers), increased benefits (such as loss prevention services) and subject matter expertise. Of approximately 91,000 distinct governmental entities operating in the United States, 75,000 are members of self-insured pools in various lines of coverage, forming approximately 500 pools. Although a relatively small corner of the insurance market, the annual contributions (self-insured premiums) to such pools have been estimated up to 17 billion dollars annually.
Limited risk of catastrophically large losses: Insurable losses are ideally independent and non-catastrophic, meaning that the losses do not happen all at once and individual losses are not severe enough to bankrupt the insurer; insurers may prefer to limit their exposure to a loss from a single event to some small portion of their capital base. Capital constrains insurers' ability to sell earthquake insurance as well as wind insurance in hurricane zones. In the United States, flood risk is insured by the federal government. In commercial fire insurance, it is possible to find single properties whose total exposed value is well in excess of any individual insurer's capital constraint. Such properties are generally shared among several insurers, or are insured by a single insurer who syndicates the risk into the reinsurance market.
There are also companies known as "insurance consultants". Like a mortgage broker, these companies are paid a fee by the customer to shop around for the best insurance policy amongst many companies. Similar to an insurance consultant, an 'insurance broker' also shops around for the best insurance policy amongst many companies. However, with insurance brokers, the fee is usually paid in the form of commission from the insurer that is selected rather than directly from the client.
The first life insurance policies were taken out in the early 18th century. The first company to offer life insurance was the Amicable Society for a Perpetual Assurance Office, founded in London in 1706 by William Talbot and Sir Thomas Allen. Edward Rowe Mores established the Society for Equitable Assurances on Lives and Survivorship in 1762.
Calculable loss: There are two elements that must be at least estimable, if not formally calculable: the probability of loss, and the attendant cost. Probability of loss is generally an empirical exercise, while cost has more to do with the ability of a reasonable person in possession of a copy of the insurance policy and a proof of loss associated with a claim presented under that policy to make a reasonably definite and objective evaluation of the amount of the loss recoverable as a result of the claim.