The financial stability and strength of an insurance company should be a major consideration when buying an insurance contract. An insurance premium paid currently provides coverage for losses that might arise many years in the future. For that reason, the viability of the insurance carrier is very important. In recent years, a number of insurance companies have become insolvent, leaving their policyholders with no coverage (or coverage only from a government-backed insurance pool or other arrangement with less attractive payouts for losses). A number of independent rating agencies provide information and rate the financial viability of insurance companies.
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.
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.
NerdWallet averaged rates for 40-year-old men and women for 20 ZIP codes in each state and Washington, D.C., from the largest insurers, up to 12 in each state. “Good drivers” had no moving violations on record and credit in the “good” tier as reported to each insurer. For the other two driver profiles, we changed the credit tier to “poor” or added one at-fault accident, keeping everything else the same. Sample drivers had the following coverage limits: