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Thursday, November 30, 2006

The Advantages of Pay-As-You-Drive Insurance

In a recent Economic Scene article for The New York Times posted here, Hal Varian explains the benefits of per-mile auto insurance. He also *patiently* answers many of the questions that come up in comments to the post (his answers are here and there are more rounds of questions and answers in the comments to that post complete with supporting models).

In the article, Hal Varian discusses work by Aaron S. Edlin and Pinar Karaca-Mandic from their paper, “The Accident Cost From Driving.” In this article from Economist's Voice, Aaron Edlin summarizes work in this area with a focus on the political advantages of using per-mile auto insurance to reduce gasoline consumption:

If Voters Won’t Go for Taxing Oil to Conserve Energy, How Do We Do It?, by Aaron S. Edlin, Economist's Voice, November, 2006: ...Lowering our dependence on oil would give the United States considerably more flexibility in Middle East policy. It would also help us to fight global climate change. Yet precious little has been done. The obvious solution of European-size taxes on gasoline and other uses of oil is just too unpopular in the United States to become law. ...

What can be done to decrease America’s energy dependence, given the public’s apparently well entrenched fear of increases in the cost of driving? One way forward may be a simple reform to auto insurance: Pay as You Drive.

Pay-as-you drive-insurance: how it would work

Currently, auto insurance is largely, but not entirely, independent of the amount of driving a person does. If an individual drives 5,000 miles per year, instead of 25,000, then her insurance rate is reduced only slightly: often, by 15% or less. ...

Suppose that, instead, ... that auto insurers were required to quote premiums on a per-mile driven basis instead of a per-year basis.

Consider a given class of drivers ... whom insurance companies currently charge $1000 per year, and who currently drive 10,000 miles per year on average. Instead of charging these drivers $1000 per year, insurers might charge 10 cents per mile driven.

The average driver ... would continue to pay the same amount—$1000 per year— assuming no change in driving behavior. However, suppose this driver chooses to cut her driving in half, to 5,000 miles per year... Then she would save $500/year, much more than under the current pricing system. Moreover, if the same driver were to double her driving, she would double her insurance cost... Such a pricing system would give her a significant incentive to reduce her driving. Elsewhere, I have estimated that such pay-as-you-drive insurance could reduce driving and gasoline consumption by 10–15%.

The political advantage of pay-as-you-drive insurance over a gas tax is that it doesn’t increase the total cost of driving, at least on average. ... Prices at the pump, of course, stay the same—making the measure much more palatable... And rather than voters simply fearing negative consequences, they can enjoy some positive ones: lowered insurance prices as a reward for changes in behavior. ...

The change won’t be painless for everyone, of course. Those who drive twice the average will pay twice as much. But that’s only fair: They also cause more accidents, and burden the environment, and worsen our dependence issue, twice as much. And charging high mileage drivers more is exactly what will give people an incentive to drive less.

The peculiar all-you-can-drive way that auto insurance is currently priced

The late Nobel Laureate William Vickrey wrote almost forty years ago that “the manner in which [auto insurance] premiums are computed and paid fails miserably to bring home to the automobile user the costs he imposes in a manner that will appropriately influence his decisions.”

The costs to which Vickrey referred were accident costs, not terrorism, climate, and national security costs. The great thing, though, is that by switching our insurance system to pay-as-you-drive insurance, we can reduce accident costs with more efficient accident pricing, and reduce these other costs as a bonus. ...

Vickrey’s point is that with each mile we drive, there is a cost in the form of accident risk. When we don’t pay the costs we impose, the incentives are obvious: we drive more than is economically efficient, causing accidents as we go. If we paid as we drove, and were charged a per-mile premium we would choose to drive less and there would be fewer accidents. And that would be fair: we would simply be forced to pay for the externalities of our conduct. ...

If Americans are successfully incentivized to drive less by pay-as-you-drive insurance, [accident] costs will fall appreciably... Several insurance carriers have begun to experiment with pay as you drive insurance, but they have not rushed to charge per-mile premiums on their own. Too many of the gains would not be captured by the company changing the policies. They need some encouragement.

The political salability of mandating pay-as-you-drive

...Per-mile premiums ... could lower the cost of driving for most people because most people drive less than the average. (Because driving quantities follow a skewed distribution, the median is considerably lower than the mean). Moreover, such premiums give drivers additional control over their costs, so they can choose to lower them still further.

There would, of course, be opposition. Although more than 50% of people drive less than the arithmetic average, many obviously drive more ... and would tend to oppose the change, at least if they vote their pocket books. Moreover, oil companies, the highway lobby and gas stations can be expected to oppose any change that leads to less driving. ...

[A] full-scale national shift to pay-as-you-drive insurance is too much to hope for. Still, a shift could be made in stages: if each insurance carrier had to issue 5% of its policies at per-mile rates, no carrier would be at a competitive disadvantage. ...

There are many pieces to a sound national energy policy, but per-mile premiums should be high on the list. What is needed is a jump start.

    Posted by on Thursday, November 30, 2006 at 12:24 AM in Economics, Environment, Market Failure, Oil, Policy | Permalink  TrackBack (0)  Comments (19)


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