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.
In determining premiums and premium rate structures, insurers consider quantifiable factors, including location, credit scores, gender, occupation, marital status, and education level. However, the use of such factors is often considered to be unfair or unlawfully discriminatory, and the reaction against this practice has in some instances led to political disputes about the ways in which insurers determine premiums and regulatory intervention to limit the factors used.
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.