Upon termination of a given policy, the amount of premium collected minus the amount paid out in claims is the insurer's underwriting profit on that policy. Underwriting performance is measured by something called the "combined ratio", which is the ratio of expenses/losses to premiums. A combined ratio of less than 100% indicates an underwriting profit, while anything over 100 indicates an underwriting loss. A company with a combined ratio over 100% may nevertheless remain profitable due to investment earnings.
Insurance involves pooling funds from many insured entities (known as exposures) to pay for the losses that some may incur. The insured entities are therefore protected from risk for a fee, with the fee being dependent upon the frequency and severity of the event occurring. In order to be an insurable risk, the risk insured against must meet certain characteristics. Insurance as a financial intermediary is a commercial enterprise and a major part of the financial services industry, but individual entities can also self-insure through saving money for possible future losses.
Plans vary greatly. But the general rule of thumb is that the less you pay per month, the higher your deductible is. Higher premiums are usually associated with lower deductibles. Generally it is beneficial for those with existing health issues to opt to pay more per month and less out-of-pocket for services. Those in good health often opt for a high deductible option in hopes that they never have to actually pay the deductible but would mostly be covered if something major happened.
Marine insurance and marine cargo insurance cover the loss or damage of vessels at sea or on inland waterways, and of cargo in transit, regardless of the method of transit. When the owner of the cargo and the carrier are separate corporations, marine cargo insurance typically compensates the owner of cargo for losses sustained from fire, shipwreck, etc., but excludes losses that can be recovered from the carrier or the carrier's insurance. Many marine insurance underwriters will include "time element" coverage in such policies, which extends the indemnity to cover loss of profit and other business expenses attributable to the delay caused by a covered loss.
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.