Closely associated with underwriting is the rate-making function. If, for example, the underwriter decides that the most important factor in discriminating between different risk characteristics is age, the rates will be differentiated according to age.

The rate is the price per unit of exposure. In fire insurance, for example, the rate may be expressed as $1 per $100 of exposed property; if an insured has $1,000 of exposed property, the premium will thus be $10. The rate reflects three major elements: the loss cost per unit of exposure, the administrative expenses, or “loading,” and the profit. In property insurance, approximately one-third of the premium covers expenses and profit, and two-thirds covers the expected cost of loss payments. These percentages vary somewhat according to the particular type of insurance.

Rates are calculated in the following way. A policy, for instance, may be written covering a class of automobiles with an expected loss frequency of 10 percent and an average collision loss of $400. The expenses of the insurer are to average 35 percent of the premium, and there must be a profit of 5 percent. The pure loss cost per unit is 10 percent of $400, or $40. The gross premium is calculated by the formula L/[1 - (E + P)], in which L equals the loss cost per unit, E equals the expense ratio, and P equals the profit ratio. In this case the gross premium would be $40/[1 - (.35 + .05)], or $66.67.

Four basic standards are used in rate making: (1) the structure of rates should allocate the burden of expenses and costs in a way that reflects as accurately as possible the differences in risk—in other words, rates should be fair; (2) a rate should produce a premium adequate to meet total losses but should not bring unreasonably large profits; (3) the rate should be revised often enough to reflect current costs; and (4) the rate structure should tend to encourage loss prevention among those who are insured.

Some examples will illustrate the nature and application of the criteria outlined above. In life insurance, the rate is generally more than adequate to meet all reasonably anticipated losses and expenses; in other words, the insured is charged an excessive premium, part of which is then returned as a dividend according to actual losses and expenses. The requirement that the rate reflect fairly the risk involved is much more difficult to achieve. In workers’ compensation insurance, the rate is expressed as a percentage of the employer’s payroll for each occupational class. This may seem fair enough, but an employer with relatively high-paid workers has fewer employees for a given amount of payroll than one whose workers are paid a lower wage. If the two employers fall into the same occupational class and have the same total payroll, they are charged the same premium even though one may have a larger number of workers than the other and hence greater exposure to loss. Fairness may be an elusive goal.

Insurance rates are revised only slowly, and, since they are based upon past experience, they tend to remain out of date. In life insurance, for example, the mortality tables used are changed only every several years, and rate adjustments are reflected in dividends. In automobile insurance, rates are revised annually or even more often, but they still tend to be out of date.

Two basic rate-making systems are in use: the manual, or class-rating, method and the individual, or merit-rating, method. Sometimes a combination of the two methods is used.

A manual rate is one that applies uniformly to each exposure unit falling in some predetermined class or group, such as people of the same age, workers of one employer, drivers meeting certain characteristics, or all residences in a given area. Presumably the members of each class are so homogeneous as to be indistinguishable so far as risk characteristics are concerned.

Merit rating is used to give recognition to individual characteristics. In commercial buildings, for example, fire insurance rates depend on such individual characteristics as the type of occupancy, the number and type of safety features, and the quality of housecleaning. In an attempt to reflect the true quality of the risk, a percentage charge or credit may be applied to the base rate for each of these features. Another example is found in employer group health insurance plans where the premium or the rate may be adjusted annually depending on the loss experience or on the amount of claims service provided.

In order to obtain broader and statistically sounder rates, insurers often pool loss and claims experience by setting up rating bureaus to calculate rates based on industrywide experience. They may have an agreement that all member companies must use the rates thus developed. The rationale for such agreements is that they help insurers meet the criteria of adequacy and fairness. Rating bureaus are used extensively in fire, marine, workers’ compensation, automobile, and crime insurance.

Profits in property and liability insurance have tended to rise and fall in fairly regular patterns lasting between five and seven years from peak to peak; this phenomenon is termed the underwriting cycle. Stages of the underwriting cycle may be described as follows: initially, when profits are relatively high, some insurers, wishing to expand sales, start to lower prices and become more lenient in underwriting. This leads to greater underwriting losses. Rising losses and falling prices cause profits to suffer. In the second stage of the cycle, insurers attempt to restore profits by increasing rates and restricting underwriting, offering coverage only to the safest risks. These restrictions may be so severe that insurance in some lines becomes unavailable in the marketplace. Insurers are able to offset a portion of their underwriting loses through earnings on investments. Eventually the increased rates and reduced underwriting losses restore profits. At this point, the underwriting cycle repeats itself.

The general effect of the underwriting cycle on the public is to cause the price of property and liability insurance to rise and fall fairly regularly and to make it more difficult to purchase insurance in some years than in others. The competition among insurers caused by the underwriting cycle tends to create cost bargains in some years. This is especially evident when interest rates are high, because greater underwriting losses will, in part, be offset by greater investment earnings.