Auto insurance rates have increased at more than twice the rate of inflation recently, with premiums hitting a national average of $1,427, an online marketplace has found.

Catastrophic weather drove some of the rate increases last year, the Zebra says. What the report only hints at, however, is how unfair these rates are to some — and how ineffectual state regulators have become at regulating them.

Consumer advocates say insurers have become adept at using Big Data to set rates for drivers using formulas that are complex and sometimes hidden from view. In the crazy, mixed-up world of car insurance, credit ratings and college diplomas can have a bigger bearing on car insurance premiums than someone’s driving record. The people most often hurt are low-income drivers who can least afford to buy state-mandated insurance, they say.

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“We feel that auto insurers have made rampant use of Big Data without adequate scrutiny from the state insurance regulators,” said Chuck Bell, programs director for Consumers Union.

The Zebra, a website that allows people to shop for auto insurance, analyzed more than 50 million quotes to compile its annual report on the state of auto insurance nationwide. The report says auto insurance rates have climbed more than 20 percent since 2011. Among its findings are these:

Adam Lyons, the Zebra’s founder and executive chairman, attributed the higher rates to extreme weather last year, such as  Hurricane Harvey. Rates have also increased partly because of the cyclical nature of the insurance business and partly because more people are on the road, he said. Lyons also said that insurers, who partner on the website, have to navigate state-by-state regulation that makes innovation difficult.

In testimony last month before the D.C.’s Department of Insurance, Securities and Banking,  an official with the Insurance Information Institute said car insurance rates have risen 15 percent in just the past two years nationwide. Yet insurance company profits declined from more than 10 percent to 1.6 percent in that time.

James Lynch, chief actuary and vice president of research and education at the Insurance Information Institute, said part of the reason is that the cost of crashes has been rising — as much as 46 percent just because of personal injury claims. Among the factors he listed was distracted driving: people are paying more attention to smartphones and fancy dashboard gadgets than to the road.

“The situation on our nation’s roads is an everyday catastrophe reaching epidemic proportions,” Lynch said in written testimony.

And there is a reason some insurers use credit scores, the Zebra says. The Federal Trade Commission has done studies showing that drivers with low credit scores are more likely to file insurance claims than drivers with higher scores. The report also says those claims tend to be costlier than claims filed by people with better credit scores.

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But count Robert Hunter a skeptic on that theory. Hunter, who is director of insurance for the Consumer Federation of America, said the reason people with lower credit scores might file more claims is that wealthier drivers sometimes refrain from filing claims because they have the means to cover the cost of some collisions out of pocket and would prefer to do so rather than risk a rate hike or policy cancellation.

If anything, Hunter said, the industry could use more, not less regulation, particularly when it comes to using factors that have little to do with one’s driving record.

“If you have more education, you pay less,” Hunter said. “If you have a higher-paying job, you pay less. If you have a better credit score, you pay less. If you own a home, you pay less. If you live in high-value areas, you pay less.”

In 2015, Consumer Reports issued a special report detailing a number of factors that insurance companies use to set rates that have nothing to do with driving risk. These included “price optimization” that relied on personal data and statistical models to figure out how willing a person is to shop around for a deal or tolerate gradual price increases, the publication says.

Hunter believes the insurers’ decision to use such factors has more to do with profits and business preferences. Using credit ratings and college degrees to set insurance rates has the effect, intended or not, of driving low-income motorists away, he said.

“We don’t think they want to serve lower-income people,” Hunter said.