Indemnification

A large number of homogeneous exposure units. The vast majority of insurance policies are provided for individual members of very large classes. Automobile insurance, for example, covered about 175 million automobiles in the United States in 2004. The existence of a large number of homogeneous exposure units allows insurers to benefit from the so-called “law of large numbers,” which in effect states that as the number of exposure units increases, the actual results are increasingly likely to become close to expected results. There are exceptions to this criterion. Lloyd's of London is famous for insuring the life or health of actors, actresses and sports figures. Satellite Launch insurance covers events that are infrequent. Large commercial property policies may insure exceptional properties for which there are no ‘homogeneous’ exposure units. Despite failing on this criterion, many exposures like these are generally considered to be insurable. Definite Loss. The event that gives rise to the loss that is subject to the insured, at least in principle, take 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.

Accidental Loss. The event that constitutes the trigger of a claim should be fortuitous, or at least outside the control of the beneficiary of the insurance. The loss should be ‘pure,’ in the sense that it results from an event for which there is only the opportunity for cost. Events that contain speculative elements, such as ordinary business risks, are generally not considered insurable.

Limited risk

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.

Limited risk of catastrophically large losses. The essential risk is often aggregation. If the same event can cause losses to numerous policyholders of the same insurer, the ability of that insurer to issue policies becomes constrained, not by factors surrounding the individual characteristics of a given policyholder, but by the factors surrounding the sum of all policyholders so exposed. Typically, insurers prefer to limit their exposure to a loss from a single event to some small portion of their capital base, on the order of 5 percent. Where the loss can be aggregated, or an individual policy could produce exceptionally large claims, the capital constraint will restrict an insurer's appetite for additional policyholders. The classic example is earthquake insurance, where the ability of an underwriter to issue a new policy depends on the number and size of the policies that it has already underwritten. Wind insurance in hurricane zones, particularly along coast lines, is another example of this phenomenon. In extreme cases, the aggregation can affect the entire industry, since the combined capital of insurers and reinsurers can be small compared to the needs of potential policyholders in areas exposed to aggregation risk. 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.

Insurers' business model

An entity seeking to transfer risk (an individual, corporation, or association of any type, etc.) becomes the 'insured' party once risk is assumed by an 'insurer', the insuring party, by means of a contract, called an insurance 'policy'. Generally, an insurance contract includes, at a minimum, the following elements: the parties (the insurer, the insured, the beneficiaries), the premium, the period of coverage, the particular loss event covered, the amount of coverage (i.e., the amount to be paid to the insured or beneficiary in the event of a loss), and exclusions (events not covered). An insured is thus said to be "indemnified" against the loss covered in the policy.

When insured parties experience a loss for a specified peril, the coverage entitles the policyholder to make a 'claim' against the insurer for the covered amount of loss as specified by the policy. The fee paid by the insured to the insurer for assuming the risk is called the 'premium'. Insurance premiums from many insureds are used to fund accounts reserved for later payment of claims—in theory for a relatively few claimants—and for overhead costs. So long as an insurer maintains adequate funds set aside for anticipated losses (i.e., reserves), the remaining margin is an insurer's profit.

The business model can be reduced to a simple equation: Profit = earned premium + investment income - incurred loss - underwriting expenses. Insurers make money in two ways: (1) through underwriting, the process by which insurers select the risks to insure and decide how much in premiums to charge for accepting those risks and (2) by investing the premiums they collect from insured parties.

Insured parties

The most complicated aspect of the insurance business is the underwriting of policies. Using a wide assortment of data, insurers predict the likelihood that a claim will be made against their policies and price products accordingly. To this end, insurers use actuarial science to quantify the risks they are willing to assume and the premium they will charge to assume them. Data is analyzed to fairly accurately project the rate of future claims based on a given risk. Actuarial science uses statistics and probability to analyze the risks associated with the range of perils covered, and these scientific principles are used to determine an insurer's overall exposure. Upon termination of a given policy, the amount of premium collected and the investment gains thereon minus the amount paid out in claims is the insurer's underwriting profit on that policy. Of course, from the insurer's perspective, some policies are winners (i.e., the insurer pays out less in claims and expenses than it receives in premiums and investment income) and some are losers (i.e., the insurer pays out more in claims and expenses than it receives in premiums and investment income).

An insurer's underwriting performance is measured in its combined ratio. The loss ratio (incurred losses and loss-adjustment expenses divided by net earned premium) is added to the expense ratio (underwriting expenses divided by net premium written) to determine the company's combined ratio. The combined ratio is a reflection of the company's overall underwriting profitability. A combined ratio of less than 100 percent indicates underwriting profitability, while anything over 100 indicates an underwriting loss.

Insurance cycle

“Float” or available reserve is the amount of money, at hand at any given moment, that an insurer has collected in insurance premiums but has not been paid out in claims. Insurers start investing insurance premiums as soon as they are collected and continue to earn interest on them until claims are paid out. The Association of British Insurers (gathering 400 insurance companies and 94% of UK insurance services) has almost 20% of the investments in the London Stock Exchange.

In the United States, the underwriting loss of property and casualty insurance companies was $142.3 billion in the five years ending 2003. But overall profit for the same period was $68.4 billion, as the result of float. Some insurance industry insiders, most notably Hank Greenberg, do not believe that it is forever possible to sustain a profit from float without an underwriting profit as well, but this opinion is not universally held. Naturally, the “float” method is difficult to carry out in an economically depressed period. Bear markets do cause insurers to shift away from investments and to toughen up their underwriting standards. So a poor economy generally means high insurance premiums. This tendency to swing between profitable and unprofitable periods over time is commonly known as the "underwriting" or insurance cycle. Property and casualty insurers currently make the most money from their auto insurance line of business. Generally better statistics are available on auto losses and underwriting on this line of business has benefited greatly from advances in computing. Additionally, property losses in the United States, due to unpredictable natural catastrophes, have exacerbated this trend.

Insurance companies

Insurance companies also earn investment profits on “float”. “Float” or available reserve is the amount of money, at hand at any given moment, that an insurer has collected in insurance premiums but has not been paid out in claims. Insurers start investing insurance premiums as soon as they are collected and continue to earn interest on them until claims are paid out. The Association of British Insurers (gathering 400 insurance companies and 94% of UK insurance services) has almost 20% of the investments in the London Stock Exchange.

In the United States, the underwriting loss of property and casualty insurance companies was $142.3 billion in the five years ending 2003. But overall profit for the same period was $68.4 billion, as the result of float. Some insurance industry insiders, most notably Hank Greenberg, do not believe that it is forever possible to sustain a profit from float without an underwriting profit as well, but this opinion is not universally held. Naturally, the “float” method is difficult to carry out in an economically depressed period. Bear markets do cause insurers to shift away from investments and to toughen up their underwriting standards. So a poor economy generally means high insurance premiums. This tendency to swing between profitable and unprofitable periods over time is commonly known as the "underwriting" or insurance cycle.

Property and casualty insurers currently make the most money from their auto insurance line of business. Generally better statistics are available on auto losses and underwriting on this line of business has benefited greatly from advances in computing. Additionally, property losses in the United States, due to unpredictable natural catastrophes, have exacerbated this trend.

A professional cyclist

In biology, energy is an attribute of all biological systems from the biosphere to the smallest living process. In an individual organism it is responsible for growth and development of a biological cell or an organelle of a biological organism. Energy is thus often said to be stored by cells in the structures of molecules of substances such as carbohydrates (including sugars) and lipids, which release energy when reacted with oxygen. In human terms, the human equivalent (H-e)[8] indicates, for a given amount of energy expenditure, the relative quantity of energy needed for human metabolism, assuming an average human energy expenditure of 12,500 kJ per day and a basal metabolic rate of 80 watts. The human equivalent assists understanding of energy flows in physical and biological systems by expressing energy units in human terms: it provides a “feel” for the use of a given amount of energy. A professional cyclist can maintain a rate of energy use of 400 watts, or 5 H-e, for a prolonged period.

In chemistry, energy is an attribute of a substance as a consequence of its atomic, molecular or aggregate structure. Since a chemical transformation is accompanied by a change in one or more of these kinds of structure, it is invariably accompanied by an increase or decrease of energy of the substances involved. In geology, continental drift, mountain ranges, volcanoes, and earthquakes are phenomena that can be explained in terms of energy transformations in the Earth's interior.[9] While meteorological phenomena like wind, rain, hail, snow, lightning, tornadoes and hurricanes, are all a result of energy transformations brought about by solar energy on the planet Earth. In cosmology and astronomy the phenomena of stars, nova, supernova, quasars and gamma ray bursts are the universe's highest-output energy transformations of matter. All stellar phenomena (including solar activity) are driven by various kinds of energy transformations. Energy in such transformations is either from gravitational collapse of matter (usually molecular hydrogen) into various classes of astronomical objects (stars, black holes, etc.), or from nuclear fusion (of lighter elements, primarily hydrogen).