Depending on the jurisdiction, the insurance premium can be either mandated by the government or determined by the insurance company in accordance to a framework of regulations set by the government. Often, the insurer will have more freedom to set the price on physical damage coverages than on mandatory liability coverages.
When the premium is not mandated by the government, it is usually derived from the calculations of an actuary based on statistical data. The premium can vary depending on many factors that are believed to have an impact on the expected cost of future claims. Those factors can include the car characteristics, the coverage selected (deductible, limit, covered perils), the profile of the driver (age, gender, driving history) and the usage of the car (commute to work or not, predicted annual distance driven).
Gender
Men average more miles driven per year than women do, and consequently have a proportionally higher accident involvement at all ages. Insurance companies cite women's lower accident involvement in keeping the youth surcharge lower for young women drivers than for their male counterparts, but adult rates are generally unisex. Reference to the lower rate for young women as "the women's discount" has caused confusion that was evident in news reports on a recently defeated EC proposal to make it illegal to consider gender in assessing insurance premiums [Women drivers' insurance threat]. Ending the discount would have made no difference to most women's premiums.Age
Teenage drivers who have no driving record will have higher car insurance premiums. However, young drivers are often offered discounts if they undertake further driver training on recognized courses, such as the Pass Plus scheme in the UK. In the U.S. many insurers offer a good grade discount to students with a good academic record and resident student discounts to those who live away from home. Drivers under 25 are considered at higher risk of having an accident, and insurance premiums tend to become lower above the age of 25. Senior drivers are often eligible for retirement discounts reflecting lower average miles driven by this age group.
Marital Status
Statistically, married drivers tend to have fewer accidents than single drivers. Subsequently, drivers who are unmarried are often charged higher insurance premiums as opposed to married drivers.
Vehicle Classification
Owners of sports cars, muscle cars, some sport utility vehicles, and motorcycles would have higher insurance premiums as opposed to compact cars, midsized cars, or luxury cars. However, in the case of motorcycles, the chance of causing extensive damage to other vehicles is relatively low (as opposed to damage to oneself) and thus liability insurance premiums are often lower.
Driving Record
The better your record, the lower your premium. If you've had accidents or serious traffic violations, you will pay more than if you have a clean driving record. You may also pay more if you haven't been insured for a number of years.
Driving Frequency
Do you drive your vehicle to work or school each day? Or do you rarely use your vehicle? The less you drive, the lower your premium is likely to be. That's because when you spend less time driving, you're less likely to have an accident.
Other Covered Driver
Adding other drivers to your insurance policy will also add cost to your premium. You will, however, pay less if they are experienced drivers with good driving histories.
Annual Mileage
The more miles you drive, the more chance for accidents. If you drive a lower than average number of miles per year, less than 10,000, you will pay less. For instance, some companies will give discounts to policyholders who carpool.
Your Habitation
Insurance companies look at local trends, such as the number of accidents, car thefts and lawsuits, as well as the cost of medical care and car repair in your environment.
Reasonable Estimation
Several car insurance plans rely on a reasonable estimation of the average annual distance expected to be driven which is provided by the insured. This discount benefits drivers who drive their cars infrequently but has no actuarial value since it is unverified.
Odometer-based Systems
Cents Per Mile Now[10](1986) advocates classified odometer-mile rates. After the company's risk factors have been applied and the customer has accepted the per-mile rate offered, customers buy prepaid miles of insurance protection as needed, like buying gallons of gasoline. Insurance automatically ends when the odometer limit (recorded on the car’s insurance ID card) is reached unless more miles are bought. Customers keep track of miles on their own odometer to know when to buy more. The company does no after-the-fact billing of the customer, and the customer doesn't have to estimate a "future annual mileage" figure for the company to obtain a discount. In the event of a traffic stop, an officer could easily verify that the insurance is current by comparing the figure on the insurance card to that on the odometer.
Critics point out the possibility of cheating the system by odometer tampering. Although the newer electronic odometers are difficult to roll back, they can still be defeated by disconnecting the odometer wires and reconnecting them later. However, as the Cents Per Mile Now website points out:
As a practical matter, resetting odometers requires equipment plus expertise that makes stealing insurance risky and uneconomical. For example, in order to steal 20,000 miles (32,000 km) of continuous protection while paying for only the 2,000 miles (3,200 km) from 35,000 miles (56,000 km) to 37,000 miles (60,000 km) on the odometer, the resetting would have to be done at least nine times to keep the odometer reading within the narrow 2,000-mile (3,200 km) covered range. There are also powerful legal deterrents to this way of stealing insurance protection. Odometers have always served as the measuring device for resale value, rental and leasing charges, warranty limits, mechanical breakdown insurance, and cents-per-mile tax deductions or reimbursements for business or government travel. Odometer tampering—detected during claim processing—voids the insurance and, under decades-old state and federal law, is punishable by heavy fines and jail.
Under the cents-per-mile system, rewards for driving less are delivered automatically without need for administratively cumbersome and costly GPS technology. Uniform per-mile exposure measurement for the first time provides the basis for statistically valid rate classes. Insurer premium income automatically keeps pace with increases or decreases in driving activity, cutting back on resulting insurer demand for rate increases and preventing today's windfalls to insurers when decreased driving activity lowers costs but not premiums.
GPS-based System
In 1998, Progressive Insurance started a pilot program in Texas in which drivers received a discount for installing a GPS-based device that tracked their driving behavior and reported the results via cellular phone to the company.[11] Policyholders were reportedly more upset about having to pay for the expensive device than they were over privacy concerns.[12] The program was discontinued in 2000.
OBDII-based system
In 2008, The Progressive Corporation launched MyRate to give drivers a customized insurance rate based on how, how much, and when their car is driven. MyRate is currently available in Alabama, Kentucky, Louisiana, Michigan, Minnesota, Maryland, New Jersey and Oregon. Driving data is transmitted to the company using an on-board telematic device. The device connects to a car's OnBoard Diagnostic (OBD-II) port (all automobiles built after 1996 have an OBD-II.) and transmits speed, time of day and number of miles the car is driven. There is no GPS in the MyRate device, so no location information is collected. Cars that are driven less often, in less risky ways and at less risky times of day can receive large discounts. Progressive has received patents on its methods and systems of implementing usage-based insurance and has licensed these methods and systems to other companies. Progressive has service marks pending on the terms Pay As You Drive and Pay How You Drive.
Source:
http://en.wikipedia.org/wiki/
http://www.iii.org/individuals/auto/b/whatdetermines/
http://www.rbcinsurance.com/auto/auto-insurance-premiums.html
