At the most basic level, initial ratemaking involves looking at the frequency and severity of insured perils and the expected average payout resulting from these perils. Thereafter an insurance company will collect historical loss data, bring the loss data to present value, and compare these prior losses to the premium collected in order to assess rate adequacy. Loss ratios and expense loads are also used. Rating for different risk characteristics involves at the most basic level comparing the losses with "loss relativities"—a policy with twice as many losses would therefore be charged twice as much. More complex multivariate analyses are sometimes used when multiple characteristics are involved and a univariate analysis could produce confounded results. Other statistical methods may be used in assessing the probability of future losses.
Some communities prefer to create virtual insurance amongst themselves by other means than contractual risk transfer, which assigns explicit numerical values to risk. A number of religious groups, including the Amish and some Muslim groups, depend on support provided by their communities when disasters strike. The risk presented by any given person is assumed collectively by the community who all bear the cost of rebuilding lost property and supporting people whose needs are suddenly greater after a loss of some kind. In supportive communities where others can be trusted to follow community leaders, this tacit form of insurance can work. In this manner the community can even out the extreme differences in insurability that exist among its members. Some further justification is also provided by invoking the moral hazard of explicit insurance contracts.
In the United Kingdom, The Crown (which, for practical purposes, meant the civil service) did not insure property such as government buildings. If a government building was damaged, the cost of repair would be met from public funds because, in the long run, this was cheaper than paying insurance premiums. Since many UK government buildings have been sold to property companies and rented back, this arrangement is now less common and may have disappeared altogether.
Know when to cut coverage. Don’t strip away coverage just for the sake of cheaper insurance. You’ll need full coverage car insurance to satisfy the terms of an auto loan, and you’ll want it as long as your car would be a financial burden to replace. But for older cars, you can drop comprehensive and collision coverage, which only pay out up to your car’s current value, minus the deductible.