Former Texas State Insurance Commission Robert Hunter, now the CFA's director of Insurance, said many of the insurance industry's pricing practices are invalid and likely "violate actuarial standards." In recent months, the organization has also attacked the way insurers have been putting more emphasis on socioeconomic data -- such as a motorist's credit score -- and less on traditional factors like tickets and accidents.
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But James Lynch, an actuary with the Insurance Information Institute, an industry group, said insurers rely on hard data to set those rates.
"Insurance companies don't pull these variables out of the hat," he said. "They look very closely to see what variables will reflect their likelihood to have accidents and adjust rates accordingly"
While he acknowledged that charging widows more "sounds cold and calculated," he said that actuarial data gathered over a long period shows that "married people are less likely to be in an accident."
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As for factoring other socioeconomic issues into rates, Lynch said insurers "have, over time, become more sophisticated" about determining what variables are included. "Now, insurance companies, as all companies, have ability to gather information over a broader scale and analyze it," he said. "(As a result) insurance rates today are fairer than they've ever been."
The latest CFA study focused specifically on how insurance companies adjust rates according to a customer's marital status. It looked at six major insurance firms: State Farm, GEICO, Farmers, Progressive, Nationwide and Liberty. The study then compared rates for two women, one aged 30, another 50, with otherwise perfect driving records, in 10 major cities.
All but State Farm penalized a new widow an average 20 percent. GEICO, meanwhile, added a premium of as much as 226 percent, in part depending upon which of the cities a woman lived in, the study found.
More broadly, the study concluded that in all but one city - Tampa -- rates were higher for a women who was single, separated, divorced or widowed, though there was "a great deal of variation" by insurer and location, noted Brobeck.
Farmers, for example, will charge a single, separated or divorced women as much as 34 percent more than a married women, with all other factors being equal, the study found.
"It's hard for us to imagine why becoming a widow makes you a worse driver," said Hunter, adding that the CFA found it difficult to make any direct correlation between driving risk and marital status. That also was true with most of the other socioeconomic factors the consumer group has looked at as part of an ongoing study of insurance industry pricing, he said.
In previous reports, the CFA revealed that lower-income motorists and those with lower-than-average credit scores were routinely charged significantly higher premiums than wealthier motorists and those with higher credit ratings. Meanwhile, CFA also found that insurers seldom adjust rates for those who clocked lower mileage each year even though there is a correlation with fewer accidents.
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According to Hunter, a trained actuarial, the insurance industry has been moving away from the traditional approach of basing premiums on known risk factors, such as the number of tickets a motorist has, and whether they have been involved in accidents. Instead, he said, there is more use of what he described as "spurious" data for which it can be difficult to show a real cause-and-effect.
In a telephone news conference, the two CFA officials suggested that companies may be favoring wealthier married couples simply because such customers are more likely to insure multiple vehicles - as well as their homes.
NBC News reached out to GEICO, which was singled out for especially strong criticism in the CFA study, but received no response. A spokesperson for Farmers could not be reached for comment.